Stable radioiodine conjugates and methods of their synthesis

Abstract

Methods are described for conjugating radioiodinated peptides or carbohydrate structures to proteins with improved yields and qualities of conjugates. In one method, specially designed radioiodinated bifunctional peptides containing nonmetabolizable amide bonds are coupled to antibodies. In a second method, radioiodinated nonmetabolizable bifunctional peptides, which also contain aminopolycarboxylates, are coupled to antibodies. In a third method, radioiodinated bifunctional aminopolycarboxylates are coupled to antibodies. In a fourth method, a hydrazide-appended antibody is coupled to a radioiodinated carbohydrate or a thiolated antibody is coupled to a hydrazide-appended and radioiodinated carbohydrate. In a fifth method a monoderivatized cyanuric chloride is used to conjugate thiolated antibody. Radioiodinated residualizing antibody conjugates made by these methods are particularly stable in vivo and are suitable for radioimmunodetection and radioimmunotherapy.

What is claimed is:  
     
         1 . An aminopolycarboxylate-appended peptide useful for radioiodinating an antibody, comprising: 
 (a) a peptide that comprises at least one D-tyrosine or tyramine, an amino terminus, a carboxy terminus formed from a D-lysine and no contiguous L-amino acids between the D-tyrosine or tyramine and the carboxy terminus;    (b) an aminopolycarboxylate conjugated via one of its carboxylic acid groups to the peptide via an ε-amino group of the D-lysine to form an aminopolycarboxylate-appended peptide; and    (c) a moiety conjugated to said aminopoly-carboxylate-appended peptide and comprising an antibody binding functional group.    
     
     
         2 . The aminopolycarboxylate-appended peptide of  claim 1 , further comprising a radioiodine atom covalently bound to the D-tyrosine or tyramine residue.  
     
     
         3 . The aminopolycarboxylate-appended peptide of  claim 1 , wherein said functional group is capable of reacting with a sulfhydryl residue of an antibody to form a covalent bond.  
     
     
         4 . The aminopolycarboxylate-appended peptide of  claim 1 , wherein said peptide contains 5-40 amino acids.  
     
     
         5 . The radioionated aminopolycarboxylate-appended peptide of  claim 2 , wherein said peptide contains 5-40 amino acids.  
     
     
         6 . The aminopolycarboxylate-appended peptide of  claim 1 , wherein said tyramine or D-tyrosine is directly linked to said D-lysine.  
     
     
         7 . The aminopolycarboxylate-appended peptide of  claim 1 , wherein said aminopolycarboxylate is selected from the group consisting of nitrilotriacetic acid, EDTA, DTPA, TTHA and backbone-substituted derivatives of nitrilotriacetic acid, EDTA, DTPA and TTHA.  
     
     
         8 . An aminopolycarboxylate-appended peptide useful for radioiodinating an antibody, comprising: 
 (a) a peptide that comprises at least one D-tyrosine or tyramine, an amino terminus, a carboxy terminus formed from a D-amino acid and no contiguous L-amino acids between the D-tyrosine or tyramine and the carboxy terminus;    (b) an aminopolycarboxylate conjugated via one of its amino groups to the peptide via an amide bond to a peptide carboxylic acid group or via a thiourea bond to a peptide amino acid residue to form an aminopolycarboxylate-appended peptide; and    (c) a moiety conjugated to said aminopolycarboxylate-appended peptide and comprising an antibody binding functional group.    
     
     
         9 . The aminopolycarboxylate-appended peptide of  claim 8 , wherein said aminopolycarboxylate is selected from the group consisting of nitrilotriacetic acid, EDTA, DTPA, TTHA and backbone-substituted derivatives of nitrilotriacetic acid, EDTA, DTPA and TTHA.  
     
     
         10 . An aminopolycarboxylate conjugate useful for radioiodinating an antibody, comprising: 
 (a) an aminopolycarboxylate; and    (b) at least one D-tyrosine or tyramine residue wherein the residue is conjugated via its amino group to a carboxyl group of the aminopolycarboxylate.    
     
     
         11 . The aminopolycarboxylate conjugate of  claim 10 , further comprising a radioiodine atom covalently bonded to the D-tyrosine or tyramine residue.  
     
     
         12 . The aminopolycarboxylate-appended peptide of  claim 10 , wherein said aminopolycarboxylate is selected from the group consisting of nitrilotriacetic acid, EDTA, DTPA, TTHA and backbone-substituted derivatives of nitrilotriacetic acid, EDTA, DTPA and TTHA.  
     
     
         13 . A stable oxidized disaccharide adduct useful for radioiodinating an antibody, comprising: 
 (a) an oxidized disaccharide that comprises galactose and at least one carbonyl group; and    (b) a D-tyrosine or tyramine.    
     
     
         14 . The stable oxidized disaccharide adduct of  claim 13 , further comprising a radioiodine atom covalently bound to the D-tyrosine or tyramine.  
     
     
         15 . The stable oxidized disaccharide adduct of  claim 13 , wherein said disaccharide is selected from the group consisting of dimelibiitoltyramine, melibiitoltyramine, melibiitol-(D)-tyrosine and dimelibiitol-(D)-tyrosine.  
     
     
         16 . The stable oxidized disaccharide adduct of  claim 13 , further comprising an antibody binding moiety comprising a functional group selected from the group consisting of an aldehyde, an amine, an isothioocyanate, an N-hydroxysuccinimide ester, an imidate ester, a maleimide, a bromoacetamide and an iodoacetamide.  
     
     
         17 . The stable oxidized disaccharide adduct of  claim 13 , further comprising a monosubstituted cyanuric monochloride.  
     
     
         18 . The stable oxidized disaccharide adduct of  claim 17 , wherein said cyanuric monochloride is monosubstituted with a maleimide.