Metal radionuclide labeled proteins for diagnosis and therapy

A method for preparing a radiolabeled polypeptide which comprises:

• combined in an aqueous medium, said polypeptide and said compound of the formula ##STR32## wherein:
• M is a metal or metal oxide radionuclide ion;
• one of Z.sup.1, Z.sup.2, Z.sup.3, or Z.sup.4, is R'CW'(HNV')n'Y', and the others are H.sub.2 or .dbd.O;
• R' is an aliphatic divalent radical of from 1 to 6 carbon atoms and 0 to 2 heteroatoms;
• V' is of the formula R'CW';
• W' is H.sub.2 or =NH or =0, with the proviso that the W' bonded to the carbon atom bonded to Y' is H.sub.2 when Y' is -NH2;
• X' is a bond, methylene or CHZ4;
• A' is H or lower alkyl of from 1 to 6 carbon atoms;
• n' is 0 to 1;
• and
• Y' is the leaving group of an active ester, said ester reacting with said polypeptide to form an amide or amidine bond with said polypeptide;
• or NH.sub.2 ;
• or NHNH.sub.2, with the proviso that when Y' is NH.sub.2 or NHNH.sub.2, said polypeptide has an oxo-group as a result of glycol cleavage of a sugar bound to said polypeptide, and said combining is under reductive amination conditions;
• wherein said compound forms a stable covalent bond to said polypeptide.