0001]The present invention is an affinity substance for the soluble protein, relates to such compounds or salts thereof having a cleavable moiety and a reactive group. BACKGROUND [0002]Recently, antibody-drug conjugate: research and development (Antibody Drug Conjugation ADC) has been actively conducted. The ADC as the name, the drug (e.g., anti-cancer agent) to antibodies is the a conjugation with drugs have direct cytotoxic activity against such cancer cells. Exemplary ADC, Immunogene Corporation and Roche Inc. T-DM1 developed jointly: there is (tradename Kadosaira (R)) (Non-Patent Documents 1-3). [0003] 　ADC, including T-DM1, the non-uniformity is a problem from the beginning of development. That is, for 70-80 degree is Lys residue in the antibody, since by reacting low molecular drug randomly drug antibody ratio (Drug Antibody Ratio: DAR) and the conjugation position is not constant. Usually it ranges DAR becomes such a random conjugation method 0-8, the bonding number of drugs have been found to differ more agents occur. Changing the number of bonds and the bonding position of recent ADC drug, it has been reported that the release rate of pharmacokinetics and drug, the effect changes. These are required to control the number and location of drug conjugation in the next-generation type ADC since. If the number and position is constant, is believed to efficacy as expected, variations of the conjugation agent, the lot difference called regulation problem solving (Non-Patent Document 4). [0004] 　Regioselective modification method of an antibody has been studied in the world, most of which are modified method using genetic engineering techniques or enzyme. With respect to genetic engineering modification method, regioselectivity, although the number selectivity can be controlled, problems such as expression efficiency of the antibody itself is reduced (decreased total yield in preparing ADC) has been pointed out. Also, it takes a long time to such construction of an antibody expression systems has become a problem (Non-Patent Documents 5-7). [0005] 　Further, a method for chemically modifying the protein contaminating an environment, such as in a cell utilizing a small molecule probe has been reported recently. This approach is utilized such as the receptors identified in performing repositioning imaging and small molecule drugs. Further, in chemical biology field, synthetic small molecule organic chemical protein modification methods using a probe has been attracting attention (Non-Patent Documents 8-10). [0006] 　Recently, C-CAP (Chemical Conjugation by Affinity Peptide) method has been developed. The method, by a method in which the peptide reagents affinity peptide (Affinity Peptide) NHS active against esters and drug are linked reacted with antibody (i.e., a manufacturing method of the ADC via a linker comprising a peptide moiety), It has been successful in position selective modification of the antibody. The method first in the world, by chemical synthesis techniques, which were successfully regioselectively modified antibody Fc region with the drug, yet practically even better results [reaction time 30 min, 70% yield (for DAR 1), regioselectivity 100%] has been confirmed. The addition of peptide reagent 5 eq approximately, has been demonstrated to be able to control the DAR 2 is a breakthrough in that it can also control modification position (Patent Document 1). CITATION Patent Document [0007] Patent Document 1: International Publication No. WO 2016/186206 Non-patent literature [0008] Non-Patent Document 1: Reichert JM et al. , Nat Biotechnol 2005; 23: 1073-8 Non-Patent Document 2: Kubota T et al. , Cancer Sci 2009; 100: 1566-72 Non-Patent Document 3: Wu AM et al. , Nat Biotechnol 2005; 23: 1137-46 Non-Patent Document 4: Junutula JR et al. , Nat Biotechnol 2008; 26: 925-32 Non-Patent Document 5: Shen BQ et al. , Nat Biotechnol 2012; 30: 184-9 Non-Patent Document 6: Hofer T et al. , Biochemistry 2009; 48: 12047-57 Non-Patent Document 7: Liu W et al. , Nat Methods 2007; 4: 239-44 Non-Patent Document 8: S. T. Laughlin et al. , Science 2008; 320,664 Non-Patent Document 9: A. E. Speers et al. , ChemBioChem 2004; 5,41 Non-Patent Document 10: Y. Takaoka et al. , Angew. Chem. Int. Ed. 2013; 52,4088 Summary of the Invention Problems that the Invention is to Solve [0009] 　The present invention, modification of soluble proteins, in particular, aims to develop techniques that allow regioselective modification of soluble protein. Means for Solving the Problems [0010] 　The present inventors have made intensive studies, as a result, (1) affinity substance to soluble proteins, and (2) a soluble protein reactive group to the amino acid residues constituting the, and (3) the affinity substance and the reaction includes a cleavable moiety between gender groups, including (4) a structural unit having a bio-orthogonal functional group to a reactive group side by cleavage at cleavage moiety (i.e., bio-orthogonal functional group and a reactive group has structural characteristic that can produce structural unit), a novel and unique based on design concept developed compounds were found to be useful in site-specific modification of soluble protein (e.g., FIG. 1 1, Figure 1-2, Figure 1-3, Figure 2). The inventors have also, by using such a compound, a peptide-free portion as a linker, the functional material (e.g., drugs) regioselective in a soluble protein (e.g., antibody drug conjugates (ADC) ) it has been found and that the can be prepared. Have potential immunogenicity, also avoids the use of a linker containing easily peptide moiety is hydrolyzed in the blood is desirable in clinical applications of the ADC. That is, the method developed by the present inventors first time, by chemical synthesis techniques, yet without using a linker comprising a peptide moiety, that was able to regioselectively modified antibody Fc region with drug be able to. The inventors also (1) to (4) structural features successfully development of various compounds having a like (eg, FIGS. 1-1, Figure 1-2, Figure 1-3 , 2), and completed the present invention. [0011] 　That is, the present invention is as follows. [0012] 　In the first embodiment, the present invention is an affinity substance for the soluble protein, a compound or a salt thereof with a cleavable moiety and a reactive group, as well as the compound or a salt thereof, regioselective modification reagent of soluble protein provide. [1] the following formula (I): A-L-B-R (I) wherein, 　A is an affinity substance to soluble proteins, 　cleavage L is a divalent group containing a cleavable moiety a sexual linker, 　B is a divalent group that does not contain a divalent group or (b) bio-orthogonal functional groups, comprising (a) a bio-orthogonal functional group, 　R is the response to the soluble protein it is a gender group. ] Represented by the affinity substance to soluble protein, a compound or a salt thereof with a cleavable moiety and a reactive group. [2] L is, (i) a biological orthogonal by the biometric orthogonality divalent cleavable linker is a group containing a cleavable moiety which a functional group having an ability to produce the reactive group side or (ii) cut by the cutting a divalent cleavable linker is a group containing no cleavage moiety capable of generating a reactive group side sexual functional group, or a salt thereof (1). [3] L is a cleavable linker of the (i), or a salt thereof [2]. [4] L is a cleavable linker of the (i), and, B is a divalent group of the (b), or a salt thereof [2] or [3]. [5] L is a cleavable linker of the (ii), and, B is a divalent group of the (a), or a salt thereof [2]. [6] affinity substance to soluble protein is a peptide, any compound or a salt thereof of [1] to [5]. [7] peptide is a binding peptide to the Fc region of a monoclonal antibody, or a salt thereof [6]. [8] binding peptide, a binding peptide to the Fc region of IgG, or a salt thereof [7]. [9] the affinity substance is an affinity substance for the following (A) comprises any one of the Fc region protein selected from the group consisting of ~ (C), and antibodies with antigen binding ability, [1] any compound or a salt thereof to [8]: (a) Fc region protein comprising the amino acid sequence of SEQ ID NO: 1; the amino acid sequence of (B) SEQ ID NO: 1, insertion of one or several amino acid residues, additions, deletions or Fc region protein comprising the amino acid sequence replaced; or (C) of SEQ ID NO: 1 amino acid sequence Fc region protein comprising the amino acid sequence of at least 90% identity. [10] binding peptide, the following formula (i): (X 1-3 ) -C- (X 2 ) -H- (Xaa1) -G- (Xaa2) -L-V-W-C-(X 1-3 ) (SEQ ID NO: 94) (i) wherein, 　X is the same or different, is any amino acid residue except cysteine, 　C is a cysteine residue, 　H is histidine 　residues, Xaa1 is an arginine residue, a leucine residue, a lysine residue, aspartic acid, glutamic acid residues, 2-aminosuberic acid residue, or a di-aminopropionic acid residue, 　G is a glycine residue, 　Xaa2 is lysine residue, a glutamine residue, a glutamic acid residue, asparagine residue or aspartic acid residue,, 　L is leucine residue a group, 　V is a valine residue, and 　W is a tryptophan residue. ] Represented by, comprises an amino acid sequence consisting of 13-17 amino acid residues, and a peptide or a salt thereof is capable of binding to human IgG and / or rabbit IgG, one of [7] to [9] the compound or a salt thereof. [11] binding peptide, the following formulas (i-1): (X 1-3 ) -C- (X 2 ) -H- (Xaa1) -G- (Xaa2) -L-V-W-C- (X 1-3 ) (SEQ ID NO: 95) (i-1) wherein, 　X is the same or different, is any amino acid residue except cysteine, 　C is a cysteine residue, 　H is histidine residues, 　Xaa1 is lysine residues, cysteine residues, aspartic acid, glutamic acid residues, 2-aminosuberic acid residue, or diaminopropionic acid residue, 　G is glycine residue a group, 　Xaa2 is a glutamate or aspartate residue, 　L is leucine residue, 　V is a valine residue, and 　W is a tryptophan residue. ] Represented by, comprises an amino acid sequence consisting of 13-17 amino acid residues, and a peptide or a salt thereof is capable of binding to human IgG and / or rabbit IgG, one of [7] to [9] the compound or a salt thereof. [12] binding peptide, the following formulas (i-2): (X 1-3 ) -C- (X 2 ) -H- (Xaa1) -G- (Xaa2) -L-V-W-C- (X 1-3 ) (SEQ ID NO: 96) (i-2) wherein, 　X is the same or different, is any amino acid residue except cysteine, 　C is a cysteine residue, 　H is a histidine 　residue, Xaa1 is a arginine residue or a leucine residue, 　G is a glycine 　residue, Xaa2 is lysine residue, a glutamine residue or aspartic acid residue,, 　L is a leucine residue, 　V is a valine residue, and, 　W is , it is a tryptophan residue. Represented by] comprises an amino acid sequence consisting of 13-17 amino acid residues, and a peptide or a salt thereof is capable of binding to human IgG and / or rabbit IgG, one of [7] to [10] the compound or a salt thereof. [13] binding peptide, the following formula (v): (X 1-3 ) -C- (Xaa3) - (Xaa4) -H- (Xaa1) -G- (Xaa2) -L-V-W-C - (Xaa5) - (Xaa6) - (Xaa7) ( SEQ ID NO: 102) (v) wherein, 　X is the same or different, is any amino acid residue except cysteine, 　C is a cysteine residue 　There, Xaa3 is alanine or lysine 　residue,, Xaa4 is tryptophan residue or a tyrosine residue,, 　H is histidine 　residues, Xaa1 is an arginine residue, a leucine residue, lysine residue, aspartic acid, glutamic acid residues, 2-aminosuberic acid residue or diaminopropionic acid residue,, 　G is a glycine residue, 　Xaa2 is lysine residue, a glutamine residue, a glutamic acid residue, asparagine residue or aspartic acid residue,, 　L is a leucine residue, 　V is a valine residue, 　W is tryptophan residue a 　group, Xaa @ 5 is a threonine residue or lysine 　residue, Xaa @ 6 is a tyrosine residue, a lysine residue or without, and 　Xaa7 is histidine residue, without or lysine residue, . Represented by] comprises an amino acid sequence consisting of 13-17 amino acid residues, and a peptide or a salt thereof is capable of binding to human IgG and / or rabbit IgG, one of [7] to [12] the compound or a salt thereof. [14] binding peptides, the following formula (vi): D-C-(Xaa3) - (Xaa4) -H- (Xaa1) -G- (Xaa2) -L-V-W-C-(Xaa @ 5) - (Xaa6) - (Xaa7) (SEQ ID NO: 103) (vi) wherein, 　D is an aspartate residue, 　C is a cysteine 　residue, Xaa3 is alanine or lysine residue, 　There, Xaa4 is tryptophan residue or a tyrosine residue,, 　H is histidine residues, 　Xaa1 is an arginine residue, a leucine residue, a lysine residue, aspartic acid, glutamic acid residues, 2-aminosuberic acid residue or diaminopropionic acid residue,, 　G is a glycine residue, 　Xaa2 is lysine residue, a glutamine residue, a glutamic acid residue, asparagine residue or aspartic acid residue,, 　L is a leucine residue, 　V is a valine residue, 　W is tryptophan residue a 　group, Xaa @ 5 is a threonine residue or lysine 　residue,, Xaa @ 6 is a tyrosine residue, a lysine residue or 　without,, Xaa @ 7 is histidine residue, without or lysine residues. ] Represented by a 13-15 comprises an amino acid sequence consisting of amino acid residues, and a peptide, or a salt thereof, characterized in that it is capable of binding to human IgG and / or rabbit IgG, [7] - [13 any compound or a salt thereof]. [15] binding peptide, the following formula (vii): D-C-(Xaa3) - (Xaa4) -H- (Xaa1) -G- (Xaa2) -L-V-W-C-T (SEQ ID NO: 104) (vii) wherein, 　D is an aspartate residue, 　C is a cysteine 　residue, Xaa3 is alanine or lysine residue, 　Xaa4 is tryptophan residue or a tyrosine residue,, 　H is histidine 　residues, Xaa1 is an arginine residue, a leucine residue, a lysine residue, aspartic acid, glutamic acid residues, 2-amino a suberic acid residue or diaminopropionic acid residue, 　G is a glycine residue, 　Xaa2 is lysine residue, a glutamine residue, a glutamic acid residue, asparagine residue or aspartic acid residue, 　L is a leucine residue, 　V is a valine residue, 　W is a tryptophan residue, and 　T is expressed by a threonine residue], the amino acid sequence consisting of 13 amino acid residues It includes and a peptide, or a salt thereof, characterized in that it is capable of binding to human IgG and / or rabbit IgG, [7] to [14] Any compound or a salt thereof. [16] binding peptide, the following formula (viii): R-G-N-C-(Xaa3) - (Xaa4) -H- (Xaa1) -G- (Xaa2) -L-V-W-C- (Xaa5) - (Xaa6) - (Xaa7) ( SEQ ID NO: 105) (viii) wherein, 　R is an arginine residue, 　G is a glycine residue, 　N is asparagine residue, 　C is a cysteine residue, 　Xaa3 is alanine or lysine 　residue,, Xaa4 is tryptophan residue or a tyrosine residue,, 　H is histidine 　residues, Xaa1 is an arginine residue, a leucine residue, a lysine residue group, aspartic acid, glutamic acid residues, 2-aminosuberic acid residue or diaminopropionic acid residue,, 　G is a glycine residue, 　Xaa2 is lysine residue, a glutamine residue, glutamate residue group, an asparagine residue or aspartic acid residue,, 　L is a leucine residue, 　V is a valine residue, 　W is a tryptophan residue, 　Xaa @ 5 is a threonine residue or lysine, a residue, 　Xaa @ 6 is a tyrosine residue, a lysine residue or without, and 　Xaa7 is histidine residues, lysine residues, Or without. ] Represented by a 13-15 comprises an amino acid sequence consisting of amino acid residues, and a peptide, or a salt thereof, characterized in that it is capable of binding to human IgG and / or rabbit IgG, [7] - [13 any compound or a salt thereof]. [17] binding peptide, characterized in that it is capable of binding to human IgG, either the compound or a salt thereof [7] - [16]. [18] binding peptide, in the amino acid sequence of (a) FNMQCQRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 92), is any amino acid residue, lysine residue, aspartic acid, glutamic acid residues, 2- aminosuberic acid residue , and one has been replaced by an amino acid residue, and selected from the group consisting of diamino propionic acid residue containing (b) an amino acid sequence having 90% identity to the amino acid sequence of SEQ ID NO: 92 is affinity peptide, or a salt thereof, or a compound or a salt thereof [7] to [9]. [19] cutting moiety is, (a) an acidic substance, basic substance, a reducing agent, oxidizing agent, treatment with one or more substances selected from the group consisting of enzymes, physical selected from the group consisting of (b) Light a cleavable moiety by any one of the left in the case of using the cleavable linker comprising a cleavable moiety of the chemical stimulation by treatment, or (c) autolytic, of any one of [1] to [18] the compound or a salt thereof. [20] The cutting resistance portion, disulfide residue, acetal residue, ketal residue, an ester residue, carbamoyl residue, alkoxyalkyl residue, an imine residue, a tertiary alkyloxy carbamate residue, silane residue, hydrazone-containing residues, phosphoramidite Romantic residue, aconityl residue, trityl residue, azo residue, vicinal diol residues, selenium residue, an aromatic ring-containing residue with an electron withdrawing group, coumarin-containing residues , sulfone-containing residue, an unsaturated bond-containing chain residue, selected from the group consisting of glycosyl residues, any of the compounds or salts thereof of [1] to [19]. Cutting portions of [21] wherein (i) is, disulfide residue, an ester residue, acetal residue, ketal residue, an imine residue, selected from the group consisting of vicinal diol residues, [2] - [ any compound or a salt thereof 20]. [22] the cleavage moiety of (ii), an ester residue, carbamoyl residue, alkoxyalkyl residue, an imine residue, a tertiary alkyloxy carbamate residue, silane residue, hydrazone-containing residues, phosphoramidite Dating residues, aconityl residue, trityl residue, azo residue, vicinal diol residues, selenium residue, an aromatic ring-containing residue with an electron withdrawing group, coumarin-containing residues, sulfone-containing residues, unsaturated bond-containing chain residue, selected from the group consisting of glycosyl residues, any compound or a salt thereof [2] - [20]. [23] cutting moiety is the following: [Formula 1] [wherein the wavy line perpendicular to the binding indicates the cleavage site, 　a plurality of R 2a , a plurality of R 2b and a plurality of R, 2c are the same or different Te, (i) a hydrogen atom or a halogen atom,; (ii) 1 monovalent hydrocarbon group; (iii) aralkyl; (iv) 1-valent heterocyclic group; (v) R c -O-, R c -C (= O) -, R c -O-C (= O) -, or R c -C (= O) -O- (R c is a hydrogen atom or a monovalent hydrocarbon group,.); (vi) NR d R e -, NR d R e -C (= O) -, NR d R e -C (= O) -O-, or R d -C (= O) -NR e - (R d and R e are the same . or different, represent a hydrogen atom or a monovalent hydrocarbon group,); or (vii) a nitro group, a sulfuric acid group, a sulfonic acid group, a cyano group or a carboxyl group, selected from the group consisting of, 　J is - CH 2 -, - O-, or a -S-, 　r is any integer of 1 ~ 4, 　○ (white circle) represents the binding to a, ● (black circle) represents a bond to B. 　Chemical structure, if it is asymmetrical about the cleavage site, ● represents the binding to A, ○ it may indicate binding to B. Corresponding to any one chemical structure selected from the group consisting of], any compound or a salt thereof [1] to [20]. [24] cleavage moiety of said (i) is the following: [Formula 2] [wherein the wavy line perpendicular to the binding indicates the cleavage site, 　R 2a is the same as [23], 　○ (white circle ) represents binding to a, ● (black circle) represents a bond to B. 　Chemical structure, if it is asymmetrical about the cleavage site, ● represents the binding to A, ○ it may indicate binding to B. Corresponding to any one chemical structure selected from the group consisting of], [2] - [19], [21], any compound or a salt thereof [23]. [25] cleavage moiety of said (ii) is selected from the group consisting of: [Chemical Formula 3] [wherein the wavy line perpendicular to the binding indicates the cleavage 　site, R 2b , R 2c , J, r is the [23] are the same, 　○ (white circle) represents the binding to a, ● (black circle) represents a bond to B. 　Chemical structure, if it is asymmetrical about the cleavage site, ● represents the binding to A, ○ it may indicate binding to B. Corresponding to any one chemical structure selected from the group consisting of], [2] - [19], [22], any compound or a salt thereof [23]. [26] L is represented by the following formula (L1) ~ (L3): La-C-Lb (L1) 　　　La-C (L2) C-Lb (L3) wherein, 　La and Lb, respectively, divalent a group, 　C is a cleavable moiety. Represented by any one of], any compound or a salt thereof [1] to [25]. [27] the La and Lb, respectively, the following (La ') and (Lb'): [Formula 4] wherein, 　p and p 'are the same or different, any integer from 0 to 10 , q 　and q 'are the same or different, 0 is an arbitrary integer of ~ 10, 　X and X' are the same or different, a carbon atom, a nitrogen atom or a single bond (wherein,, X is a nitrogen atom If it is, R 1b is absent, 'when it is a nitrogen atom, R X 1b' if there is no .X is a single bond, R 1a and R 1b is absent, 'when is a single bond, R X 1a' and R 1b ' is does not 　exist), R 1a , R 1b , R 1a' and R 1b ' are the same or different, wherein (i) an atom or a group selected from the group consisting of ~ (vii). ] Represented by The compound or a salt thereof [26]. [28] is a divalent group containing a bio-orthogonal functional groups, azide residue, aldehyde residues, thiol residue, alkyne residue, alkene residue, tetrazine residue, nitrones residue, hydroxyl amine residue, a nitrile residues, hydrazine residue, a ketone residue, boron residue, cyano benzothiazole residue, allyl residue, a phosphine residue, maleimide residue, disulfide residue, thioester group, alpha-halo carbonyl residue, isonitrile remaining group, sydnone residue, a bio orthogonal functional group selected from the group consisting of selenium residue is a divalent group containing in the main chain, any of the compounds or salts thereof of [1] to [27]. [29] is a divalent group containing a bio-orthogonal functional groups, azide residue, aldehyde residues, thiol residue, alkyne residue, alkene residue, halogen residue, tetrazine residue, nitrones residue, hydroxylamine residues, nitrile residue, hydrazine residue, a ketone residue, boron residue, cyano benzothiazole residue, allyl residue, a phosphine residue, maleimide residue, disulfide residue, alpha-halo carbonyl residue, isonitrile residues, sydnone residues, biological orthogonal functional group selected from the group consisting of selenium residue is a divalent group containing a side chain, any of the compounds or salts thereof of [1] to [27]. [30] bio orthogonal functional group, the following: [Chemical Formula 5] 　wherein, R 1f , single or multiple R 1 g and a single or plurality of R 1h are the same or different, wherein (i) ~ atom or a group selected from the group consisting of (vii) or an electron withdrawing group, 　- is a bond. ) Is any one represented by, any compound or a salt thereof [1] to [29]. [31] a divalent group of the (b) is an alkylene optionally substituted, optionally substituted cycloalkylene, aryl which may be substituted, an optionally substituted divalent heterocyclic group, -NR A - (R A Hydrogen atom or a substituent),, - O-or any compound or salt thereof selected from the group consisting of two or more thereof, [1] to [30],. [32] B is a compound represented by the following formula (B-1): [Chemical Formula 6] wherein, 　Y is, -NH -, - O -, - CH 2 - or the following formula (B-2),: [Formula 7 ] (wherein, 　V and V 'are the same or different, -NH -, - O -, - CH 2 -, or a single 　bond, V1 is a divalent group containing a bio-orthogonal functional group There, 　s is any integer from 0 to 10, 　is ○ and ● in the formula (B-2), respectively, represented by the formula (B-1) in the same orientation as ○ and ● 　in.), Z (if Z is a hydrogen atom, -C (= Z) -, the -CH oxygen atom, a sulfur atom or a hydrogen atom, 2 -. showing a), and, 　○ in the formula (B-1) (white circles ) denotes the bond to the portion of the L-side, ● (black circle) represents a bond to portions of the R side. ] Represented by any of the compounds or salts thereof of [1] to [31]. [33] reactive groups, lysine residues, a specific reactive group on either one of the side chains of tyrosine residues or tryptophan residue, of any one of [1] to [32] the compound or a salt thereof. [34] reactive group is a specific reactive group to the side chain of a lysine residue, or a salt thereof [33]. [35] reactive groups, the following: [Formula 8] 　[wherein, R 5a and R 5c are the (i) atoms selected from the group consisting of ~ (vii) or a 　group, R 5b is electron a withdrawing group, 　j is an arbitrary integer from 1 to 5, 　k is an arbitrary integer of 1-4. Corresponding to any one chemical structure selected from the group consisting of], any compound or a salt thereof [1] to [34]. [36] A and atomic number of the main chain connecting the R is 4 to 20, any of the compounds or salts thereof of [1] to [35]. [37] backbone linking the A and R does not contain a cyclic structure, any compound or a salt thereof [1] to [36]. [38] partial structure represented by L-B does not include a peptide moiety, either a compound or a salt thereof [1] to [37]. [39] A compound represented by the formula (I) is the following (I '): 'A-B2-L'-B1 -R (I) in [wherein, 　A and R are the same as those of the formula (I) 　L' is a divalent group containing a cleavable moiety cleavage a sexual linker, 　B1 and B2 are the same or different, is a divalent group that does not contain a divalent group or (b) bio-orthogonal functional groups, comprising (a) a bio-orthogonal functional group, 　B1 and B2 may have a symmetrical structure around the L '. Is a compound represented by], any compound or a salt thereof [1] to [38]. [40] The formula (I ') compound represented by the following (I' '): [Chemical Formula 9] wherein, 　A and R are the same as those of the formula (I) of [1] There, 　C is a cleavable 　moiety, p, p ', q, q', X, X ', R 1a , R 1a' , R 1b , and R 1b ' is [27] the formulas described (La ') and (Lb' is the same as that of), 　Y and Y 'are the same or different, are the same as Y in the formulas described [32] (B-1), 　Z and Z 'are the same or different, is the same as Z in the above formula (B-1). ] Represented by The compound or a salt thereof [39]. [41] the following formula (I): A-L-B-R (I) wherein, 　A is an affinity substance to soluble proteins, 　cleavage L is a divalent group containing a cleavable moiety a sexual linker, 　B is a divalent group that does not contain a divalent group or (b) bio-orthogonal functional groups, comprising (a) a bio-orthogonal functional group, 　R is the response to the soluble protein it is a gender group. ] Represented by the affinity substance to soluble protein, compounds or salts thereof, regioselective modification reagents soluble protein having a cleavable moiety and a reactive group. [42] the following formula (I): A-L-B-R (I) wherein, 　A is an affinity substance for the antibody, 　L is cleavable a divalent group containing a cleavable moiety is a linker, 　B is a divalent group that does not contain a divalent group or (b) bio-orthogonal functional groups, comprising (a) a bio-orthogonal functional group, 　R is the side chain of a lysine residue a specific reactive groups relative. ] Represented by the affinity substance, compound or a salt thereof with a cleavable moiety and a reactive group to the antibody. [43] the following formula (I): 　the following formula (I): A-L-B-R ( I) in [wherein, 　A is an affinity substance for the antibody, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B is (a ) is a divalent group, or a bivalent group having (b) containing no bio orthogonal functional groups, including the biological orthogonal functional group, 　R is specific reactive groups to the side chain of a lysine residue it is. ] Represented by the affinity substance, compound or a salt thereof, regioselective modification reagent antibody with a cleavable moiety and a reactive group to the antibody. [0013] 　Second, the present invention provides affinity substance to soluble proteins, and soluble protein or a salt thereof with a cleavable moiety, and its manufacturing method. (Affinity substance to soluble proteins, and soluble protein or a salt thereof with a cleavable moiety) [44] following formula (II): A-L-B-R'-T (II) wherein, 　A is soluble an affinity substance to the protein, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B is (a) a divalent group containing a bio-orthogonal functional groups or, (b) a divalent group containing no bio orthogonal functional group, 　R 'is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein. ] Represented by the soluble protein, or a salt thereof having an affinity substance for the soluble protein, and a cleavable moiety. [45] soluble protein is a monoclonal antibody, a soluble protein, or a salt thereof [44]. [46] soluble protein is an IgG antibody, a soluble protein, or a salt thereof [44] or [45]. [47] soluble protein is human, either soluble protein or a salt thereof [44] - [46]. [48] soluble protein, comprises the following (A) ~ (C) any one of the Fc region protein chosen from the group consisting of, and is an antibody having an antigen binding capacity, either [44] - [47] Kano soluble protein or a salt thereof: Fc region protein comprising the amino acid sequence of (a) SEQ ID NO: 1; the amino acid sequence of (B) SEQ ID NO: 1, insertion of one or several amino acid residues, additions, deletions or Fc region protein comprising the substituted amino acid sequence; or (C) of SEQ ID NO: 1 amino acid sequence Fc region protein comprising the amino acid sequence of at least 90% identity. [49] soluble protein, the inclusion of certain amino acid residues, one or more in a target region of 1 to 50 amino acid residues contiguous, and, the particular amino acids in non-target regions in other than the target region comprising residues 5 or more, 　structural units represented by a-L-B-R 'is 30% or more positions selectivity for one or more specific amino acid residues contained in said target area in attached, either soluble protein or a salt thereof [44] - [48]. [50] The target region is a region of 1 to 10 amino acid residues contiguous, soluble protein, or a salt thereof [49]. [51] The target region is a region of 1 to 3 amino acid residues contiguous, soluble protein, or a salt thereof [50]. [52] the target region, (a) a region consisting of amino acid residues 246 to 248 of the human IgG Fc region, (b) a region comprising the amino acid residues 288-290 of the human IgG Fc region, or ( c) a region comprising the amino acid residues 317 of the human IgG Fc region, soluble protein or a salt thereof [51]. [53] The regioselectivity is 50% or more, either soluble protein or a salt thereof [49] - [52]. [54] The regioselectivity of at least 70%, soluble protein or a salt thereof [53]. [55] The regioselectivity is 90% or more, the soluble protein or a salt thereof [54]. [56] The specific amino acid residues, a number (where the respective N-terminal and C-terminal side around a particular amino acid present in a particular position, a is any integer from 1 to 10 in the region of up to a remote location of the amino acid residues in which) in addition to the specific amino acid residues present in said particular position, without amino acids residues of a particular amino acid residue of the same kind, [49] - [ either soluble protein or a salt thereof 55]. [57] wherein the soluble protein is a multimeric protein comprising a plurality of monomeric protein, 　T is the corresponding plurality of target regions in a plurality of monomeric protein, A-L-B-R 'results having a structural unit represented by the multimeric protein a-L-B-R' to plurality have a structural unit represented by, [44] either soluble protein to [56] or a salt. [58] wherein the soluble protein is an antibody that includes a plurality of heavy chains, 　T is the table in the plurality of target regions corresponding in a plurality of heavy chains, 'the result having a structural unit represented by the antibody A-L-B-R' A-L-B-R is to plurality have a structural unit, either soluble protein or a salt thereof [44] - [57]. [59] The number of the heavy chain is two, soluble protein or a salt thereof [58]. [60] the portion formed by the reaction between a reactive group with a soluble protein, a lysine residue, a tyrosine residue or for a tryptophan residue, a lysine residue, a tyrosine residue or any one of the tryptophan residues, one of a part produced by the reaction of the specific reactive group to the side chain, either soluble protein or a salt thereof [44] - [59]. [61] the portion formed by the reaction between the reactive group and soluble proteins, the portion formed by the reaction between a lysine residue, a specific reactive group to the side chain of a lysine residue there, either soluble protein or a salt thereof [44] - [60]. [62] The portion formed by the reaction is the following: [Formula 10] [wherein, ● (black circle) indicates the bond to the portion of the T side, ○ (white circle) shows binding to parts of the B-side . Straight line perpendicular to the bond indicates a bond formed by the reaction. Corresponding to any one chemical structure selected from the group consisting of], either soluble protein or a salt thereof [44] - [61]. [63] A and atomic number of the main chain connecting the R 'is 4 to 20, either soluble protein or a salt thereof [44] - [62]. [64] backbone linking the A and R does not contain a ring structure, either soluble protein or a salt thereof [44] - [63]. [65] partial structure represented by L-B does not include a peptide moiety, either soluble protein or a salt thereof [44] - [64]. [66] A compound represented by the formula (II) is represented by the following (II '): A-B2-L'-B1-R'-T (II') wherein, 　A, R 'and T are formula is the same as that of (II) 　L 'is a divalent cleavable linker is a group containing a cleavable moiety, 　the B1 and B2, the same or different, (a) biological orthogonal functional groups a divalent group that does not contain a divalent group or (b) bio-orthogonal functional groups, including, 　B1 and B2 may have a symmetrical structure around the L '. It is a compound represented by], either soluble protein or a salt thereof [44] - [65]. [67] above-mentioned formula (II ') compound represented by the following (II' '): [Formula 11] wherein, 　A, R' and T are those of formula (II) according [44] is the same as, 　C is a cleavable moiety, 　p and p 'are the same or different and can be any integer from 0 to 10, 　q and q' are the same or different, from 0 to 10 It is an arbitrary integer, 　X and X 'are the same or different, a carbon atom, a nitrogen atom or a single bond (wherein, when X is a nitrogen atom, R 1b is absent, X' when it is a nitrogen atom, R 1b ' If there is no .X it is a single bond, R 1a and R 1b is absent, X' when is a single bond, R 1a ' and R 1b' is does not 　exist), R 1a , R 1b , R 1a ' and R 1b' are the same or different, (i) a hydrogen atom or a halogen atom,; (ii) 1 monovalent hydrocarbon group; (iii) aralkyl; (iv) 1-valent heterocyclic group ; (v) R c -O-, R c -C (= O) -, R c -O-C (= O) -, or R c-C (= O) -O- (R c is a hydrogen atom or a monovalent hydrocarbon group,.); (Vi) NR d R e -, NR d R e -C (= O) -, NR d R e -C (= O) -O-, or R d -C (= O) -NR e - (R d and R e are the same or different, a hydrogen atom or a monovalent hydrocarbon group, shown);. or (vii) a nitro group, a sulfuric acid group, a sulfonic acid group, a cyano group or a carboxyl group, selected from the group consisting of, 　Y and Y 'are the same or different, [32] the formulas described ( B-1) is the same as the Y, 　Z and Z 'are the same or different, is the same as Z in the above formula (B-1). ] Represented by the soluble protein, or a salt thereof [66]. [68] the following formula (II): A-L-B-R'-T (II) wherein 　A is an affinity substance for the antibody, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B is or a divalent group, comprising (a) a bio-orthogonal functional group (b) a divalent group containing no bio orthogonal functional group, 　R 'is an antibody, the portion formed by the reaction between a specific reactive group to the side chain of a lysine residue Yes, 　T is an antibody. ] Represented by the antibody or its salt with an affinity substance for the antibody, and the cleavage moiety. [0014] (Affinity substance, and a method for producing a soluble protein or a salt thereof with a cleavable moiety to the soluble protein) a [69] affinity substance, and the soluble proteins with cleavable moiety or a salt thereof to soluble proteins , 　the following formula (I): a-L-B-R (I) wherein, 　a is an affinity substance for the soluble protein, 　L is a divalent group which is cleavable linker comprising a cleavable moiety and a, 　B is a divalent group that does not contain a divalent group or (b) bio-orthogonal functional groups, comprising (a) a bio-orthogonal functional group, 　R is a reactive group to said soluble protein it is. ] Represented by the affinity substance to soluble protein, compounds having cleavable moiety and a reactive group or a salt thereof, is reacted with a soluble protein, 　the following formula (II): A-L-B-R'- T (II) wherein, 　a, L, and B are the same as those of the formula (I), 　R 'is a moiety formed by the reaction between the reactive group and soluble proteins, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, and generating a soluble protein or a salt thereof with a cleavable portion. [70] a soluble protein antibody, reactive group is a specific reactive group to the side chain of a lysine residue, the method of [69]. [0015] 　Third, the present invention provides affinity substance to soluble proteins, cleavage moiety, complex or salt thereof with a functional material and soluble proteins, and a manufacturing method thereof. (Affinity substance to soluble proteins, cleavage moiety, complex or salt thereof with a functional material and soluble proteins) [71] following formula (III): A-L-B '(- F) -R'-T (III) wherein, 　a is an affinity substance for the soluble protein, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B ', the functional material and the biological orthogonality a divalent group containing a moiety formed by the reaction between a functional group, 　F is a functional material, 　R 'is a moiety formed by the reaction between the reactive group and soluble protein , 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, cleavage moiety, complex or salt thereof with a functional material and soluble proteins. [72] soluble protein is a monoclonal antibody, a complex or a salt thereof [71]. [73] soluble protein is an IgG antibody, conjugate, or a salt thereof [71] or [72]. [74] soluble protein is human, either complex or a salt thereof [71] - [73]. [75] soluble protein comprises any one of the Fc region protein selected from the group consisting of the following (A) ~ (C), and antibodies that have binding activity to the antigen, either [71] - [74] Kano complex or a salt thereof: Fc region protein comprising the amino acid sequence of (a) SEQ ID NO: 1; the amino acid sequence of (B) SEQ ID NO: 1, insertion of one or several amino acid residues, additions, deletions or Fc region protein comprising the substituted amino acid sequence; or (C) of SEQ ID NO: 1 amino acid sequence Fc region protein comprising the amino acid sequence of at least 90% identity. [76] soluble protein, the inclusion of certain amino acid residues, one or more in a target region of 1 to 50 amino acid residues contiguous, and, the particular amino acids in non-target regions in other than the target region the residue containing 5 or more, 　a-L-B - the structural unit represented by '(F) -R' is 30% for one or more specific amino acid residues contained in said target area attached at more regioselectivity, either complex or a salt thereof [71] - [75]. [77] The specific amino acid residues, a number (where the respective N-terminal and C-terminal side around a particular amino acid present in a particular position, a is any integer from 1 to 10 in the region of up to a remote location of the amino acid residues in which) in addition to the specific amino acid residues present in said particular position, without amino acids residues of a particular amino acid residue and the like, a composite of [76] body or a salt thereof. [78] wherein the soluble protein is a multimeric protein comprising a plurality of monomeric protein, 　T is, in a corresponding plurality of target regions in a plurality of monomeric protein, A-L-B - results having a structural unit represented by '(F) -R', said multimeric protein A -L-B - to plurality have a structural unit represented by '(F) -R', either complex or a salt thereof [71] - [77]. [79] wherein the soluble protein is an antibody that includes a plurality of heavy chains, 　T is at a plurality of target regions corresponding in a plurality of heavy chain, A-L-B '( - F) -R 'results having a structural unit represented by the antibody a-L-B' (- F) to a plurality have a structural unit represented by -R ', the composite of any one of [71] - [78] body or a salt thereof. Is a divalent group containing a moiety formed by the reaction between [80] functional materials and bio-orthogonal functional group, disulfide residue, acetal residue, ketal residue, an ester residue, carbamoyl residue, alkoxy alkyl residue, an imine residue, a tertiary alkyloxy carbamate residue, silane residue, hydrazone-containing residues, phosphoramidite Romantic residue, aconityl residue, trityl residue, azo residue, vicinal diol residues, selenium residues, aromatic ring-containing residue with an electron withdrawing group, coumarin-containing residues, sulfone-containing residue, an unsaturated bond-containing chain residue, divalent comprising a reactive moiety selected from the group consisting of glycosyl residues it is a group, either complex or a salt thereof [71] - [79]. [81] The portion formed by the reaction is the following: [Chem 12] [wherein the wavy line perpendicular to the bond indicates a bond formed by the reaction, 　a plurality of R 2a , a plurality of R 2bAnd a plurality of R 2c are the same or different, (i) a hydrogen atom or a halogen atom,; (ii) 1 monovalent hydrocarbon group; (iii) aralkyl; (iv) 1-valent heterocyclic group; (v ) R c -O-, R c -C (= O) -, R c -O-C (= O) -, or R c -C (= O) -O- (R c is a hydrogen atom or, . represent a monovalent hydrocarbon group); (vi) NR d R e -, NR d R e -C (= O) -, NR d R e -C (= O) -O-, or R d - C (= O) -NR e - (R d and R eAre the same or different, represent a hydrogen atom or a monovalent hydrocarbon group. ); Or (vii) a nitro group, a sulfuric acid group, a sulfonic acid group, a cyano group or a carboxyl group, selected from the group consisting of, 　J is, -CH 2 -, - O-, or a -S-, 　r is is any integer from 1 ~ 4, 　○ (white circle) represents the binding to a, ● (black circle) represents a bond to B. 　Chemical structure, if it is asymmetrical about the cleavage site, ● represents the binding to A, ○ it may indicate binding to B. Corresponding to any one chemical structure selected from the group consisting of], either complex or a salt thereof [71] - [80]. [82] the portion formed by the reaction between a reactive group with a soluble protein, a lysine residue, a tyrosine residue or a tryptophan residue, a lysine residue, a tyrosine residue or any one of the tryptophan residues, one of a part produced by the reaction between a specific reactive group to the side chain, either complex or a salt thereof [71] - [81]. [83] the portion formed by the reaction between the reactive group and soluble proteins, the portion formed by the reaction between a lysine residue, a specific reactive group to the side chain of a lysine residue there, either complex or a salt thereof [71] - [82]. [84] The portion formed by the reaction is the following: [Formula 13] [Here, ● (black circle) indicates the bond to the portion of the T side, ○ (white circle) shows binding to parts of the B-side. Corresponding to any one chemical structure selected from the group consisting of], either complex or a salt thereof [71] - [83]. [85] functional substance is a drug or label substance, either complex or a salt thereof [71] - [84]. [86] functional substance is a low molecular weight compound, either the complex or a salt thereof [71] - [85]. [87] drugs are anticancer agents, complex or a salt thereof [85] or [86]. [88] A and atomic number of the main chain connecting the R 'is 4 to 20, either complex or a salt thereof [71] - [87]. [89] backbone linking the A and R does not contain a ring structure, either complex or a salt thereof [71] - [88]. [90] partial structure represented by L-B does not include a peptide moiety, either complex or a salt thereof [71] - [89]. Compounds represented by [91] Formula (III) is a compound represented by the following formula (III '): A-B2' (- F2) -L'-B1 '(- F1) -R'-T (III') [ wherein, 　a, R 'and T are the same as those of the formula (II), 　L' is a divalent cleavable linker is a group containing a cleavable moiety, 　B1 'and B2' are , same or different, it is a divalent group containing a moiety formed by the reaction between the functional material and the biological orthogonal functional groups, 　F1 and F2 are the same or different, is a functional 　material, B1 '(- F1) and B2' (- F2) may have a symmetrical structure around the L '. ] Represented by either complex or a salt thereof [71] - [90]. [92] Formula (III ') compound represented by the following (III' '): [Formula 14] wherein, 　A, R' and T are those of [71] the formulas described (III) is the same as, 　C is a cleavable moiety, 　p and p 'are the same or different and can be any integer from 0 to 10, 　q and q' are the same or different, from 0 to 10 is any integer, 　X and X 'are the same or different, a carbon atom, a nitrogen atom or a single bond (wherein, when X is a nitrogen atom, R 1b is not present, X' is a nitrogen atom If it is, R '1b If there is no .X it is a single bond, R 1a and R 1b is absent, X' when is a single bond, R 1a ' and R 1b' is absent) with 　Yes, R 1A , R 1b , R 1a ' and R 1b' are the same or different, selected from the group consisting of the (i) ~ (vii), 　Y and Y 'are the same or different, [32] the formulas described (B -1) is a residue obtained by removing one hydrogen atom from Y of, 　Z and Z 'are the same or different, are the same as Z in the formula (B-1), 　F and F' are the same or different, is a functional material. ] Represented by complex or a salt thereof [91]. [93] the following formula (III): A-L-B '(- F) -R'-T (III) wherein, 　A is an affinity substance for the antibody, 　L comprises a cleavable moiety a cleavable linker is a divalent group, 　B 'is a divalent group containing a moiety formed by the reaction between the functional material and the biological orthogonal functional group, 　F is a functional material There, 　R 'is an antibody, a moiety formed by the reaction between a specific reactive group to the side chain of a lysine residue, 　T is an antibody. ] Represented by the affinity substance, a complex or a salt thereof with a functional material and antibodies. [0016] (Affinity substance to soluble proteins, cleavage moiety, functional materials and composite or a salt thereof having a soluble protein) affinity substance, cleavable moiety to [94] soluble protein, a functional substance and the soluble protein a complex or a salt thereof having, 　formula (II): a-L-B-R'-T (II) wherein, 　a is an affinity substance for the soluble protein, 　L is , a divalent cleavable linker is a group containing a cleavable moiety, 　B is (a) a divalent group comprising a bio-orthogonal functional group, 　R 'is a reactive group with a soluble protein a moiety formed by the reaction between, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, and the soluble protein or a salt thereof with a cleavable moiety, is reacted with a functional material, 　the following formula (III): A-L-B '(- F) -R'-T (III) wherein, 　a, L, R 'and T are the same as those of the formula (II), 　B' is between the functional material and the biological orthogonal functional groups a divalent group includes a portion of the product by the reaction, 　F is a functional material. ] Represented by, including affinity substance to soluble proteins, cleavage moiety, the complex having a functional substance and the soluble protein or to generate a salt thereof, method. [95] soluble protein is an antibody, reactive group is a specific reactive group to the side chain of a lysine residue, the method of [94]. [96] affinity substance to soluble proteins, cleavage moiety, a functional material and complexes or a salt thereof having a soluble protein, (A) the following formula (I): A-L-B-R (I) wherein, 　a is an affinity substance for the soluble protein, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B is (a) bio-orthogonal functional group a divalent group containing, 　R is a reactive group to the soluble protein. Compound represented by or a salt thereof in], is reacted with a soluble protein, 　the following formula (II): A-L-B-R'-T (II) wherein, 　A, L, and B, the They are the same as those of the formula (I) 　R 'is a moiety formed by the reaction between the reactive group and soluble proteins, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, and to produce a soluble protein or a salt thereof with a cleavable moiety, and (B) an affinity substance for the soluble protein, and soluble proteins with a cleavable moiety or the salt is reacted with the functional material, 　the following formula (III): a-L-B '(- F) -R'-T (III) wherein, 　a and L, the formula (I) is the same as that of, 　R 'and T are the same as those of the formula (II), 　2 B' may include a portion formed by the reaction between the functional material and the biological orthogonal functional groups the valence of the group, 　F is a functional material. ] Represented by, including affinity substance to soluble proteins, cleavage moiety, the complex having a functional substance and the soluble protein or to generate a salt thereof, method. [0017] 　Fourth, the present invention provides a method for producing a soluble protein having a biological orthogonal functional groups. [97] A method of manufacturing a soluble protein or a salt thereof having a biological orthogonal functional groups, 　the following formula (II): A-L-B-R'-T (II) wherein, 　A is a soluble protein for a affinity substance, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B is (a) a divalent group containing a bio-orthogonal functional group or (a) biological, a divalent group that does not contain an orthogonal functional group, 　R 'is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, and by cutting the soluble protein or cleavage moiety of a salt thereof with a cleavable moiety, 　the following formula (IV): L1-B-R'-T (IV) wherein, 　B, R 'and T are the same as those of the formula (II), 　L1 is (i') 1 monovalent group including the biological orthogonal functional group, or (ii ') a biological orthogonal is a monovalent group containing no sexual function. ] Represented by includes generating a soluble protein or a salt thereof having a biological orthogonal functional groups, methods. [98] L is, (i) a biological orthogonal by the biometric orthogonality divalent cleavable linker is a group containing a cleavable moiety which a functional group having an ability to produce the reactive group side or (ii) cut by the cutting a divalent cleavable linker is a group containing no cleavage moiety capable of generating a reactive group side sexual functional group, the method of [97]. [99] L is a cleavable linker of the 　(i), L1 is (i ') a monovalent group containing a bio-orthogonal functional group, 　2 and B, wherein (a) or (b) it is a valence of the group, the method of [98]. [100] L is the cleavable linker of the (i), 　L1 is a monovalent group containing the a (i ') bio orthogonal functional group, 　a divalent group of B is the (b), the method of [98] or [99]. [101] L is the cleavable linker of the (ii), 　L1 is (i ') a monovalent group that does not contain a bio-orthogonal functional group, 　B is a divalent group of the (a) the method of [98]. [102] a soluble protein antibody, reactive group is a specific reactive group to the side chain of a lysine residue, either the method of [97] - [101]. [103] A method of manufacturing a soluble protein or a salt thereof having a biological orthogonal functional group, (A) the following formula (I): A-L-B-R (I) wherein 　A is an affinity substance for the soluble protein, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B is a divalent group comprising (a) a bio-orthogonal functional group, or (a) a divalent group containing no bio orthogonal functional group, 　R is a reactive group to said soluble protein. Compound represented by or a salt thereof in], is reacted with a soluble protein, 　the following formula (II): A-L-B-R'-T (II) wherein, 　A, L, and B, the are the same as those of the formula (I) 　R 'is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, and to produce a soluble protein or a salt thereof with a cleavable moiety, and (B) an affinity substance for the soluble protein, and soluble proteins with a cleavable moiety or cutting the cutting portions of a salt thereof, 　the following formula (IV): L1-B-R'-T (IV) in 　[wherein, B, R 'and T are the same as those of the formula (II) Yes, 　L1 is a monovalent group that does not contain the 'monovalent group or (ii, including the biological orthogonal functions) bio orthogonal functional group (i)'. ] Represented by includes generating a soluble protein or a salt thereof having a biological orthogonal functional groups, methods. [0018] 　Fifth, the present invention provides a method for producing a soluble protein or a salt thereof with a functional material. [104] A method of manufacturing a soluble protein or a salt thereof with a functional material, 　the following formula (III): A-L-B '(- F) -R'-T (III) wherein, 　A is a affinity substance to soluble protein, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B 'is produced by the reaction between the functional material and the biological orthogonal functional groups a divalent group containing a moiety which, 　F is a functional material, 　R 'is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, cleavage moiety, complex or by cutting the cutting portions of a salt thereof with a functional material and soluble proteins, or 　the following formula (IV): L1-B- R'-T (IV) wherein, 　L1 is a monovalent group that does not contain the 'monovalent group or (ii, including the biological orthogonal functions) bio orthogonal functional group (i)', 　B is a divalent group that does not contain a divalent group or (b) bio-orthogonal functional groups, comprising (a) a bio-orthogonal functional group, 　R 'is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein. ] Represented by the soluble protein, or a salt thereof having a biological orthogonal functional group reacted with the functional material, 　the following formula (V): F- (L1-B) '- R'-T (V) [ wherein, 　L1 is a monovalent group that does not contain the 'monovalent group or (ii, including the biological orthogonal functions) bio orthogonal functional group (i)', 　B is (a) a biological orthogonal a divalent group that does not contain a divalent group or (b) bio-orthogonal functional groups, including sexual functional group, 　a structural unit represented by (L1-B) 'is the functional substance, (i ') and (a divalent structural units containing portion produced by the reaction between one or both of the biological orthogonal functional groups in a), 　F is a functional material, 　R' is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein. ] Represented by includes generating a soluble protein or a salt thereof with a functional substance, method. [105] The affinity substance to soluble proteins, cleavage moiety, by cutting the complex or cutting portions of a salt thereof with a functional material and soluble proteins, 　the following formula (V1): L1-B '(- F ) -R'-T (V1) [in the formula, 　L1 is a monovalent group that does not contain the 'monovalent group or (ii, including the biological orthogonal functions) bio orthogonal functional group (i)', 　B ', F, R' and T are it is the same as those of the formula (III). ] Represented by a method that includes generating a soluble protein or a salt thereof with a functional material, a method of [104]. [106] The soluble protein or a salt thereof having the biological orthogonal functional group is reacted with one or two functional substances, 　the following formula (V2): F-L1 '-B-R'-T ( V2) wherein, 　B, R 'and T are the same as those of the formula (IV), 　L1' is the functional substance, a monovalent group containing a (i ') bio orthogonal functional groups a divalent group containing a moiety formed by the reaction between, 　F is a functional material. ], Or 　the following formula (V3): Fa-L1 '-B' (- Fb) -R'-T (V3) wherein, 　R 'and T are the same as those of the formula (IV), 　L1 'is the same as in the formula (V2), 　B' is a divalent group containing a moiety formed by the reaction between the functional material and the biological orthogonal functional groups, 　Fa and Fb are respectively the same or different functional materials. ] Represented by a method that includes generating a soluble protein or a salt thereof with a functional material, a method of [104]. [107] a soluble protein antibody, reactive group is a specific reactive group to the side chain of a lysine residue, The method of any of [104] - [106]. [108] A method of manufacturing a soluble protein or a salt thereof with a functional material, (A) the following formula (II): A-L-B-R'-T (II) wherein, 　A is soluble an affinity substance to the protein, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B is a divalent group comprising (a) a bio-orthogonal functional group, 　R ' is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, and the soluble protein or a salt thereof with a cleavable moiety, is reacted with a functional material, 　the following formula (III): A-L-B '(- F) -R'-T (III) wherein, 　a, L, R 'and T are the same as those of the formula (II), 　B' is between the functional material and the biological orthogonal functional groups a divalent group includes a portion of the product by the reaction, 　F is a functional material. ] Represented by the affinity substance to soluble proteins, cleavage moiety, functional materials and composite or to produce a salt thereof having a soluble protein, and (B) an affinity substance for the soluble protein, cleavage moiety , by cutting the complex or cutting portions of a salt thereof with a functional material and soluble proteins, 　the following formula (V1): L1-B '(- F) -R'-T (V1) wherein, 　L1 is (i ') a monovalent group that does not include a monovalent group, or (ii, including the biological orthogonal functional group') bio orthogonal functional group, 　B ', F, R' and T, the is the same as in formula (III). ] Represented by includes generating a soluble protein or a salt thereof with a functional substance, method. [109] A method of manufacturing a soluble protein or a salt thereof with a functional material, (A) the following formula (I): A-L-B-R (I) wherein, 　A is the affinity for the soluble protein a sex material, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B is a divalent group comprising (a) a bio-orthogonal functional group, 　R is a soluble is a reactive group to the protein. ] Represented by the affinity substance to soluble protein, compounds having cleavable moiety and a reactive group or a salt thereof, is reacted with a soluble protein, 　Formula (II): A-L-B-R'-T (II) in 　[wherein, A, L, and B are the same as those of the formula (I) 　R 'is reacted with the soluble protein a moiety formed by the reaction between gender groups, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, and to produce a soluble protein or a salt thereof with a cleavable moiety, the soluble protein or with an affinity substance, and cleaving moiety to (B) said soluble protein the salt is reacted with the functional material, 　the following formula (III): a-L-B '(- F) -R'-T (III) wherein, 　a and L, the formula (I) are the same as ones, 　R 'and T are the same as those of the formula (II), 　B' is bivalent containing a moiety formed by the reaction between the functional material and the biological orthogonal functional groups a group, 　F is a functional material. ] Represented by the affinity substance to soluble proteins, cleavage moiety, functional materials and composite or to produce a salt thereof having a soluble protein, and (C) an affinity substance for the soluble protein, cleavage moiety , by cutting the complex or cutting portions of a salt thereof with a functional material and soluble proteins, 　the following formula (V1): L1-B '(- F) -R'-T (V1) wherein, 　L1 is, (i' a monovalent group or (ii ') bio orthogonal functional groups, including) bio orthogonal functional groups a monovalent group that does not contain, 　B ', F, R' and T are the same as the formula of (III). ] Represented by includes generating a soluble protein or a salt thereof with a functional substance, method. [110] A method of manufacturing a soluble protein or a salt thereof with a functional material, (A) the following formula (II): A-L-B-R'-T (II) wherein, 　A is soluble an affinity substance to the protein, 　L is a divalent cleavable linker is a group containing a cleavable moiety, 　B is (a) a divalent group containing a bio-orthogonal functional group or, (a) a divalent group containing no bio orthogonal functional group, 　R 'is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, and by cutting the soluble protein or cleavage moiety of a salt thereof with a cleavable moiety, 　the following formula (IV): L1-B-R'-T (IV) wherein, 　B, R 'and T are the same as those of the formula (II), 　L1 is a monovalent group that does not contain the 'monovalent group or (ii, including the biological orthogonal functions) bio orthogonal functional group (i)'. ] Represented by, generating a soluble protein or a salt thereof having a biological orthogonal functional groups, and (B) a soluble protein or a salt thereof having the biological orthogonal functional groups, one or more functions is reacted with sexual material, 　the following formula (V2) F-L1 '-B-R'-T (V2) wherein, 　B, R' and T are the same as those of the formula (IV), 　L1 'is the functional substance, (i' is a divalent group containing a moiety formed by the reaction between a monovalent group comprising a) bio-orthogonal functional group, 　F is a functional material . ], Or 　the following formula (V3): Fa-L1 '-B' (- Fb) -R'-T (V3) wherein, 　R 'and T are the same as those of the formula (IV), 　L1 'is the same as in the formula (V2), 　B' is a divalent group containing a moiety formed by the reaction between the functional material and the biological orthogonal functional groups, 　Fa and Fb are respectively the same or different functional materials. ] Represented by includes generating a soluble protein or a salt thereof with a functional substance, method. [111] A method of manufacturing a soluble protein or a salt thereof with a functional substance, (A) formula (I): A-L-B-R (I) wherein, 　A is an affinity substance to soluble proteins, 　cleavage L is a divalent group containing a cleavable moiety a sexual linker, 　B is a divalent group that does not contain a divalent group or (a) bio-orthogonal functional groups, comprising (a) a bio-orthogonal functional group, 　R is the response to the soluble protein it is a gender group. Compound represented by or a salt thereof in], is reacted with a soluble protein, 　the following formula (II): A-L-B-R'-T (II) wherein, 　A, L, and B, the are the same as those of the formula (I) 　R 'is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein. ] Represented by the affinity substance to soluble proteins, and to produce a soluble protein or a salt thereof with a cleavable moiety, the soluble protein or with an affinity substance, and cleaving moiety to (B) said soluble protein cutting the cutting portions of salt, 　the following formula (IV): L1-B-R'-T (IV) in 　[wherein, B, R 'and T are the same as those of the formula (II) , 　L1 is a monovalent group that does not contain the 'monovalent group or (ii, including the biological orthogonal functions) bio orthogonal functional group (i)'. ] Represented by, generating a soluble protein or a salt thereof having a biological orthogonal functional groups, and (C) a soluble protein or a salt thereof having the biological orthogonal functional groups, one or more functions is reacted with sexual material, 　the following formula (V2) F-L1 '-B-R'-T (V2) wherein, 　B, R' and T are the same as those of the formula (IV), 　L1 'is the functional substance, (i' is a divalent group containing a moiety formed by the reaction between a monovalent group comprising a) bio-orthogonal functional group, 　F is a functional material . ], Or 　the following formula (V3): Fa-L1 '-B' (- Fb) -R'-T (V3) wherein, 　R 'and T are the same as those of the formula (IV), 　L1 'is the same as in the formula (V2), 　B' is a divalent group containing a moiety formed by the reaction between the functional material and the biological orthogonal functional groups, 　Fa and Fb are respectively the same or different functional materials. ] Represented by includes generating a soluble protein or a salt thereof with a functional substance, method. [0019] 　Sixth, the present invention provides a soluble protein, or a salt thereof, and a method of manufacturing the bio-orthogonal functional groups regioselectively. (Bio orthogonal functional groups soluble protein or a salt thereof with a regioselective) a (1) a soluble protein or a salt thereof having a biological orthogonal function in position selectively, 　soluble protein, contiguous 1-50 It includes one or more specific amino acid residues in a target area consisting of pieces of amino acid residues, and wherein a particular amino acid residue comprises 5 or more, and in a non-target region other than the target area 　bio orthogonality functional groups, via a linker that does not contain a peptide portion, attached at more than 30% regioselectivity for one or more specific amino acid residues contained in the target region, bio orthogonality functional soluble protein or its salt with a base to regioselective. [2] the following formula (IV): L1-B-R'-T (IV) wherein, 　L1 is, (i ') 1 monovalent group including the biological orthogonal functional group, or (ii') a biological orthogonal a monovalent group containing no sexual functional groups, 　B is a divalent group that does not contain a divalent group or (b) bio-orthogonal functional groups, comprising (a) a bio-orthogonal functional group, 　R 'is a moiety formed by the reaction between the reactive group and soluble protein, 　T is a soluble protein, 　Wherein the soluble protein contains one or more specific amino acid residues in a target region of 1 to 50 amino acid residues contiguous, and, the particular amino acid residues in a non-target region other than the target region the including five or more. Represented by], and L1-B-R 'represented by the structural units, 30% or more positions selectivity for one or more specific amino acid residues contained in the target region of the soluble protein bonded to that, the soluble protein or a salt thereof having a biological orthogonal function in position selectively. [3] soluble protein is a monoclonal antibody, a soluble protein, or a salt thereof [1] or [2]. [4] soluble protein is an IgG antibody, either soluble protein or a salt thereof (1) to (3). [5] soluble protein is that derived from human, either soluble protein or a salt thereof (1) to (4). [6] soluble protein comprises any one of the Fc region protein selected from the group consisting of the following (A) ~ (C), and an antibody having an antigen binding ability, any of [1] to [5] Kano soluble protein or a salt thereof: Fc region protein comprising the amino acid sequence of (a) SEQ ID NO: 1; the amino acid sequence of (B) SEQ ID NO: 1, insertion of one or several amino acid residues, additions, deletions or Fc region protein comprising the substituted amino acid sequence; or (C) of SEQ ID NO: 1 amino acid sequence Fc region protein comprising the amino acid sequence of at least 90% identity. [7] The target region is a region consisting of 1 to 10 amino acid residues contiguous, either soluble protein or a salt thereof of [1] to [6]. [8] The target region is a region consisting of 1 to 3 amino acid residues contiguous, either soluble protein or a salt thereof [1] to [7]. [9] the target region, (a) a region consisting of amino acid residues 246 to 248 of the human IgG Fc region, (b) a region comprising the amino acid residues 288-290 of the human IgG Fc region, or ( c) a region comprising the amino acid residues 317 of the human IgG Fc region, soluble protein or a salt thereof [8]. [10] The regioselectivity is 50% or more, either soluble protein or a salt thereof [1] to [9]. [11] The regioselectivity of at least 70%, soluble protein, or a salt thereof [10]. [12] The regioselectivity is 90% or more, the soluble protein or a salt thereof [11]. [13] The specific amino acid residues, a number (where the respective N-terminal and C-terminal side around a particular amino acid present in a particular position, a is any integer from 1 to 10 in the region of up to a remote location of the amino acid residues in which) in addition to the specific amino acid residues present in said particular position, without amino acids residues of a particular amino acid residue of the same kind, [1] to [ either soluble protein or a salt thereof 12]. [14] wherein the soluble protein is a multimeric protein comprising a plurality of monomeric protein, 　biological in more specific amino acid residues present at the positions of a plurality of monomeric protein which contains a large amount of protein results with orthogonal functional groups, said multimeric protein has a plurality of biological orthogonal functional group, (1), either soluble protein or a salt thereof [3] to [13]. [15] wherein the soluble protein is an antibody that includes a plurality of heavy chains, 　results in a plurality of specific amino acid residues present at the positions in the plurality of heavy chain contained in antibodies with biological orthogonal functional groups, antibody has a plurality of biological orthogonal functional group, (1), either soluble protein or a salt thereof [3] to [14]. [16] wherein the soluble protein is a multimeric protein comprising a plurality of monomeric protein, 　T is a plurality of target regions corresponding of the plurality of monomeric protein, with A-L-B-R ' results having a structural unit represented by, a plurality have a structural unit multimeric protein is represented by a-L-B-R ' , either soluble protein or a salt thereof [2] to [13]. [17] wherein the soluble protein is an antibody that includes a plurality of heavy chains, 　T is a plurality of target regions corresponding in more heavy, a structural unit represented by A-L-B-R ' a result, the antibody is a plurality have a structural unit represented by a-L-B-R ' , [2] to [13], either soluble protein or a salt thereof [16]. [18] The number of the heavy chain is two, soluble protein or a salt thereof [15] or [17]. [19] L1 is a compound represented by the following formula (L1-1) ~ (L1-2): C1-Lb (L1-1) C1 (L1-2) wherein, 　Lb is a divalent group, 　C1 is a bio-orthogonal functional group or groups other than bio-orthogonal functional group. Represented by any one of], either soluble protein or a salt thereof [2] to [13], [16] - [18]. [20] the Lb satisfies the following formula (Lb '): [Formula 15] wherein, 　p is any integer of 0 ~ 10, 　q is any integer of 0 ~ 10, 　X is a carbon atom, a nitrogen atom or a single bond (wherein, when X is a nitrogen atom, R, 1b If there is no .X is a single bond, R 1a and R 1b is absent) 　and, R 1a , and R 1b are the same or different, selected from the group consisting of a hydrogen atom or the above substituents. 　○ (white circle) shows the binding to C1, ● (black circle) represents a bond to B. ] Represented by the soluble protein, or a salt thereof [19]. [21] is a divalent group containing a bio-orthogonal functional groups, azide residue, aldehyde residues, thiol residue, alkyne residue, alkene residue, tetrazine residue, nitrones residue, hydroxyl amine residue, a nitrile residues, hydrazine residue, a ketone residue, boron residue, cyano benzothiazole residue, allyl residue, a phosphine residue, maleimide residue, disulfide residue, thioester group, alpha-halo carbonyl residue, isonitrile remaining group, sydnone residue, a bio orthogonal functional group selected from the group consisting of selenium residue is a divalent group containing in the main chain, either soluble protein or its salt [1] to [20]. [22] is a divalent group containing a bio-orthogonal functional groups, azide residue, aldehyde residues, thiol residue, alkyne residue, alkene residue, halogen residue, tetrazine residue, nitrones residue, hydroxylamine residues, nitrile residue, hydrazine residue, a ketone residue, boron residue, cyano benzothiazole residue, allyl residue, a phosphine residue, maleimide residue, disulfide residue, alpha-halo carbonyl residue, isonitrile residues, sydnone residues, biological orthogonal functional group selected from the group consisting of selenium residue is a divalent group containing in the side chain, either soluble protein or its salt [1] to [20]. [23] bio orthogonal functional group, the following: [Chemical Formula 16] 　wherein, WE CLAIM A compound having an affinity substance to a soluble protein, a cleavable portion, and a reactive group represented by the following Formula (I): A-L-B-R (I) wherein A is the affinity substance to the soluble protein; L is a cleavable linker which is a divalent group comprising a cleavable portion; B is (a) a divalent group comprising a bioorthogonal functional group or (b) a divalent group comprising no bioorthogonal functional group; and R is the reactive group to the soluble protein; or a salt thereof. 2. The compound or salt thereof according to claim 1, wherein L is (i) a cleavable linker which is a divalent group comprising a cleavable portion having an ability to form a bioorthogonal functional group on a reactive group side by cleavage or (ii) a cleavable linker which is a divalent group comprising a cleavable portion having no ability to form a bioorthogonal functional group on a reactive group side by cleavage. 3. The compound or salt thereof according to claim 2, wherein L is the cleavable linker (i). 4. The compound or salt thereof according to claim 2 or 3, wherein L is the cleavable linker (i), and B is the divalent group (b). 5. The compound or salt thereof according to claim 2, wherein L is the cleavable linker (ii); and B is the divalent group (a). 6. The compound or salt thereof according to any one of claims 1 to 5, wherein the affinity substance to the soluble protein is a peptide. 7. The compound or salt thereof according to claim 6, wherein the peptide is a binding peptide to an Fc region of a monoclonal antibody. 8. The compound or salt thereof according to claim 7, wherein the binding peptide is a binding peptide to an Fc region of IgG. 9. The compound or salt thereof according to any one of claims 1 to 8, wherein the affinity substance is an affinity substance to an antibody comprising any one Fc region protein selected from the group consisting of the following (A) to (C) and having antigen-binding ability: (A) an Fc region protein comprising the amino acid sequence of SEQ ID NO: 1; (B) an Fc region protein comprising an amino acid sequence with one or several amino acid residues inserted, added, deleted, or substituted in the amino acid sequence of SEQ ID NO: 1; and (C) an Fc region protein comprising an amino acid sequence having 90% or more identity to the amino acid sequence of SEQ ID NO: 1. 10. The compound or salt thereof according to any one of claims 7 to 9, wherein the binding peptide is a peptide comprising an amino acid sequence consisting of 13 to 17 amino acid residues represented by the following Formula (i) : (Xi_3)-C-(X2)-H-(Xaal)-G-(Xaa2)-L-V-W-C-(Xi_3) (SEQ ID NO: 94) (i) wherein Xs are the same or different from each other, and are each any amino acid residue other than cysteine; C is a cysteine residue; H is a histidine residue; Xaal is an arginine residue, a leucine residue, a lysine residue, an aspartic acid residue, a glutamic acid residue, a 2-amino suberic acid residue, or a diaminopropionic acid residue; G is a glycine residue; Xaa2 is a lysine residue, a glutamine residue, a glutamic acid residue, an asparagine residue, or an aspartic acid residue; L is a leucine residue; V is a valine residue; and W is a tryptophan residue; and capable of binding to human IgG and/or rabbit IgG, or a salt thereof. 11. The compound or salt thereof according to any one of claims 7 to 9, wherein the binding peptide is a peptide comprising an amino acid sequence consisting of 13 to 17 amino acid residues represented by the following Formula (i-D : (X1-3)-C-(X2)-H-(Xaal)-G-(Xaa2)-L-V-W-C-(X1-3) (SEQ ID NO: 95) (i-1) wherein Xs are the same or different from each other, and are each any amino acid residue other than cysteine; C is a cysteine residue; H is a histidine residue; Xaal is a lysine residue, a cysteine residue, an aspartic acid residue, a glutamic acid residue, a 2-amino suberic acid residue, or a diaminopropionic acid residue; G is a glycine residue; Xaa2 is a glutamic acid residue or an aspartic acid residue; L is a leucine residue; V is a valine residue; and W is a tryptophan residue; and capable of binding to human IgG and/or rabbit IgG, or a salt thereof. 12. The compound or salt thereof according to any one of claims 7 to 10, wherein the binding peptide is a peptide comprising an amino acid sequence consisting of 13 to 17 amino acid residues represented by the following Formula (i-2) : (Xi_3)-C-(X2)-H-(Xaal)-G-(Xaa2)-L-V-W-C-(Xi_3) (SEQ ID NO: 96) (i-2) wherein Xs are the same or different from each other, and are each any amino acid residue other than cysteine; C is a cysteine residue; H is a histidine residue; Xaal is an arginine residue or a leucine residue; G is a glycine residue; Xaa2 is a lysine residue, a glutamine residue, or an aspartic acid residue; L is a leucine residue; V is a valine residue; and W is a tryptophan residue; and capable of binding to human IgG and/or rabbit IgG, or a salt thereof. 13. The compound or salt thereof according to any one of claims 7 to 12, wherein the binding peptide is a peptide comprising an amino acid sequence consisting of 13 to 17 amino acid residues represented by the following Formula (v) : (Xi-3) -C- (Xaa3) - (xaa4) -H- (Xaal) -G- (Xaa2) -L-V-W-C- (Xaa5) -(Xaa6)-(Xaa7) (SEQ ID NO: 102) (v) wherein Xs are the same or different from each other, and are each any amino acid residue other than cysteine; C is a cysteine residue; Xaa3 is an alanine residue or a lysine residue; Xaa4 is a tryptophan residue or a tyrosine residue; H is a histidine residue; Xaal is an arginine residue, a leucine residue, a lysine residue, an aspartic acid residue, a glutamic acid residue, a 2-amino suberic acid residue, or a diaminopropionic acid residue; G is a glycine residue; Xaa2 is a lysine residue, a glutamine residue, a glutamic acid residue, an asparagine residue, or an aspartic acid residue; L is a leucine residue; V is a valine residue; W is a tryptophan residue; Xaa5 is a threonine residue or a lysine residue; Xaa6 is a tyrosine residue, a lysine residue, or absent; and Xaa7 is a histidine residue, a lysine residue, or absent; and capable of binding to human IgG and/or rabbit IgG, or a salt thereof. 14. The compound or salt thereof according to any one of claims 7 to 13, wherein the binding peptide is a peptide comprising an amino acid sequence consisting of 13 to 15 amino acid residues represented by the following Formula (vi) : D-C-(Xaa3)-(Xaa4)-H-(Xaal)-G-(Xaa2)-L-V-W-C-(Xaa5)-(Xaa6)-(Xaa7) (SEQ ID NO: 103) (vi) wherein D is an aspartic acid residue; C is a cysteine residue; Xaa3 is an alanine residue or a lysine residue; Xaa4 is a tryptophan residue or a tyrosine residue; H is a histidine residue; Xaal is an arginine residue, a leucine residue, a lysine residue, an aspartic acid residue, a glutamic acid residue, a 2-amino suberic acid residue, or a diaminopropionic acid residue; G is a glycine residue; Xaa2 is a lysine residue, a glutamine residue, a glutamic acid residue, an asparagine residue, or an aspartic acid residue; L is a leucine residue; V is a valine residue; W is a tryptophan residue; Xaa5 is a threonine residue or a lysine residue; Xaa6 is a tyrosine residue, a lysine residue, or absent; and Xaa7 is a histidine residue, a lysine residue, or absent; and capable of binding to human IgG and/or rabbit IgG, or a salt thereof. 15. The compound or salt thereof according to any one of claims 7 to 14, wherein the binding peptide is a peptide comprising an amino acid sequence consisting of 13 amino acid residues represented by the following Formula (vii): D-C-(Xaa3)-(Xaa4)-H-(Xaal)-G-(Xaa2)-L-V-W-C-T (SEQ ID NO: 104) (vii) wherein D is an aspartic acid residue; C is a cysteine residue; Xaa3 is an alanine residue or a lysine residue; Xaa4 is a tryptophan residue or a tyrosine residue; H is a histidine residue; Xaal is an arginine residue, a leucine residue, a lysine residue, an aspartic acid residue, a glutamic acid residue, a 2-amino suberic acid residue, or a diaminopropionic acid residue; G is a glycine residue; Xaa2 is a lysine residue, a glutamine residue, a glutamic acid residue, an asparagine residue, or an aspartic acid residue; L is a leucine residue; V is a valine residue; W is a tryptophan residue; and T is a threonine residue; and capable of binding to human IgG and/or rabbit IgG, or a salt thereof. 16. The compound or salt thereof according to any one of claims 7 to 13, wherein the binding peptide is a peptide comprising an amino acid sequence consisting of 13 to 15 amino acid residues represented by the following Formula (viii): R-G-N-C-(Xaa3)-(Xaa4)-H-(Xaal)-G-(Xaa2)-L-V-W-C-(Xaa5)-(Xaa6)-(Xaa7) (SEQ ID NO: 105) (viii) wherein R is an arginine residue; G is a glycine residue; N is an asparagine residue; C is a cysteine residue; Xaa3 is an alanine residue or a lysine residue; Xaa4 is a tryptophan residue or a tyrosine residue; H is a histidine residue; Xaal is an arginine residue, a leucine residue, a lysine residue, an aspartic acid residue, a glutamic acid residue, a 2-amino suberic acid residue, or a diaminopropionic acid residue; G is a glycine residue; Xaa2 is a lysine residue, a glutamine residue, a glutamic acid residue, an asparagine residue, or an aspartic acid residue; L is a leucine residue; V is a valine residue; W is a tryptophan residue; and Xaa5 is a threonine residue or a lysine residue; Xaa6 is a tyrosine residue, a lysine residue, or absent; and Xaa7 is a histidine residue, a lysine residue, or absent; and capable of binding to human IgG and/or rabbit IgG, or a salt thereof. 17. The compound or salt thereof according to any one of claims 7 to 16, wherein the binding peptide is capable of binding to human IgG. 18. The compound or salt thereof according to any one of 5 claims 7 to 9, wherein the binding peptide is an affinity peptide comprising an amino acid sequence (a) in which any amino acid residue is substituted with one amino acid residue selected from the group consisting of a lysine residue, an aspartic acid residue, a glutamic acid residue, 10 a 2-amino suberic acid residue, and a diaminopropionic acid residue in the amino acid sequence of FNMQCQRRFYEALHDPNLNEEQRNARIRSIRDDC (SEQ ID NO: 92), and (b) having 90% or more identity to the amino acid sequence of SEQ ID NO: 92, or a salt thereof. 15 19. The compound or salt thereof according to any one of claims 1 to 18, wherein the cleavable portion is a portion cleavable by any of (a) treatment with one or more substances selected from the group consisting of an acidic 20 substance, a basic substance, a reducing agent, an oxidizing agent, and an enzyme, (b) treatment by physicochemical stimulus selected from the group consisting of light, and (c) being left when a cleavable linker comprising a self-decomposing cleavable portion is used. 25 20. The compound or salt thereof according to any one of claims 1 to 19, wherein the cleavable portion is selected from the group consisting of a disulfide residue, an acetal residue, a ketal residue, an ester residue, a carbamoyl 30 residue, an alkoxyalkyl residue, an imine residue, a tertiary alkyloxy carbamate residue, a silane residue, a hydrazone-containing residue, a phosphoramidate residue, an aconityl residue, a trityl residue, an azo residue, a vicinal diol residue, a selenium residue, an aromatic ring-containing residue having an electron-withdrawing group, a coumarin-containing residue, a sulfone-containing residue, an unsaturated bond-containing chain residue, and a glycosyl residue. 21. The compound or salt thereof according to any one of claims 2 to 20, wherein the cleavable portion of (i) is selected from the group consisting of a disulfide residue, an ester residue, an acetal residue, a ketal residue, an imine residue, and a vicinal diol residue. 22. The compound or salt thereof according to any one of claims 2 to 20, wherein the cleavable portion of (ii) is selected from the group consisting of an ester residue, a carbamoyl residue, an alkoxyalkyl residue, an imine residue, a tertiary alkyloxy carbamate residue, a silane residue, a hydrazone-containing residue, a phosphoramidate residue, an aconityl residue, a trityl residue, an azo residue, a vicinal diol residue, a selenium residue, an aromatic ring-containing residue having an electron-withdrawing group, a coumarin-containing residue, a sulfone-containing residue, an unsaturated bond-containing chain residue, and a glycosyl residue. 23. The compound or salt thereof according to any one of claims 1 to 20, wherein the cleavable portion corresponds to any one chemical structure selected from the group consisting of the following: P OH A* *00* oeH* ^ 0-^.OH 0 OH u o u^,un S,*^ OH H H > oyJl^O* ^^ <^q. Jp ox^ where a wavy line orthogonal to a bond indicates a cleavage site; a plurality of R2a, a plurality of R2b, and a plurality of R2c are the same or different from each other, and are selected from the group consisting of: (i) a hydrogen atom or a halogen atom; (ii) a monovalent hydrocarbon group; (iii) aralkyl; (iv) a monovalent heterocyclic group; (v) Rc-0-, Rc-C(=0)-, Rc-0-C(=0)-, or RC-C (=0)-0- wherein Rc indicates a hydrogen atom or a monovalent hydrocarbon group; (vi) NRdRe-, NRdRe-C(=0)-, NRdRe-C (=0) -0-, or Rd-C(=0)-NRe-wherein Rd and Re are the same or different from each other, and indicate a hydrogen atom or a monovalent hydrocarbon group; and (vii) a nitro group, a sulfuric acid group, a sulfonic acid group, a cyano group, or a carboxy group; J is -CH2-, -0-, or -S-; r is any integer of 1 to 4; a symbol of "white circle" indicates a bond to A, and a symbol of "black circle" indicates a bond to B; and when a chemical structure is asymmetrical with respect to the cleavage site, a symbol of "black circle" may indicate a bond to A, and a symbol of "white circle" may indicate a bond to B. 24. The compound or salt thereof according to any one of claims 2 to 19, 21, and 23, wherein the cleavable portion of (i) corresponds to any one chemical structure selected from the group consisting of the following: where a wavy line orthogonal to a bond indicates a cleavage site; R.2a are the same as that of claim 23; a symbol of "white circle" indicates a bond to A, and a symbol of "black circle" indicates a bond to B; and when a chemical structure is asymmetrical with respect to the cleavage site, a symbol of "black circle" may Docket No. PAMA-19181-PCT_final 462 indicate a bond to A, and a symbol of “white circle” may indicate a bond to B. 25. The compound or salt thereof according to any one of 5 claims 2 to 19, 22, and 23, wherein the cleavable portion of (ii) corresponds to any one chemical structure selected from the group consisting of the following: cA^ ° °c^v v^a H ^ Ov OH o O^N^N ^O*^* ^^OH O SrA^N^ vow©-0;- N^N •*2b ^2b ^2b ^2b V^/ 10 where a wavy line orthogonal to a bond indicates a cleavage site; R2b, R2c, J, and r are the same as those of claim 23; a symbol of “white circle” indicates a bond to A, and 15 a symbol of “black circle” indicates a bond to B; and when a chemical structure is asymmetrical with respect to the cleavage site, a symbol of “black circle” may Docket No. PAMA-19181-PCT_final 463 indicate a bond to A, and a symbol of “white circle” may indicate a bond to B. 26. The compound or salt thereof according to any one of 5 claims 1 to 25, wherein L is represented by any one of the following Formulae (L1) to (L3): La-C-Lb (L1) La-C (L2) C-Lb (L3) 10 wherein La and Lb are each a divalent group; and C is a cleavable portion. 27. The compound or salt thereof according to claim 26, 15 wherein La and Lb are represented by the following (La') and (Lb'), respectively: R1tX R1a' (La’) and R1a X R1b (Lb’) 20 wherein p and p' are the same or different from each other, and are each any integer of 0 to 10; q and q' are the same or different from each other, and are each any integer of 0 to 10; 25 X and X' are the same or different from each other, and are each a carbon atom, a nitrogen atom, or a single bond; wherein when X is a nitrogen atom, R1b is absent; when X' is a nitrogen atom, R1b' is absent; when X is a single bond, R1a and R1b are absent; and when X' is a single 30 bond, R1a' and R1b' are absent; and R1a, R1b, R1a', and R1b' are the same or different from each other, and are each an atom or a group selected from Docket No. PAMA-19181-PCT_final 464 the group consisting of the (i) to (vii). 28. The compound or salt thereof according to any one of claims 1 to 27, wherein the divalent group comprising a 5 bioorthogonal function group is a divalent group comprising a bioorthogonal functional group selected from the group consisting of an azide residue, an aldehyde residue, a thiol residue, an alkyne residue, an alkene residue, a tetrazine residue, a nitron residue, a hydroxyamine residue, 10 a nitrile residue, a hydrazine residue, a ketone residue, a boronic acid residue, a cyanobenzothiazole residue, an allyl residue, a phosphine residue, a maleimide residue, a disulfide residue, a thioester residue, an a-halocarbonyl residue, an isonitrile residue, a sydnone residue, and a 15 selenium residue in a main chain thereof. 29. The compound or salt thereof according to any one of claims 1 to 27, wherein the divalent group comprising a bioorthogonal function group is a divalent group comprising 20 a bioorthogonal function group selected from the group consisting of an azide residue, an aldehyde residue, a thiol residue, an alkyne residue, an alkene residue, a halogen residue, a tetrazine residue, a nitron residue, a hydroxyamine residue, a nitrile residue, a hydrazine 25 residue, a ketone residue, a boronic acid residue, a cyanobenzothiazole residue, an allyl residue, a phosphine residue, a maleimide residue, a disulfide residue, an 4^* &- "°^t ^ ^ ^ ^ JU ,Y< <