LABELING OF PROTEINS BY ORGANOMETALLIC COMPLEXES OF RHENIUM(I) - SYNTHESIS AND BIOLOGICAL-ACTIVITY OF THE CONJUGATES

We describe herein a totally new pathway for the introduction of rheni um in the form of low oxidation state organometallic complexes covalen tly attached to various proteins. The synthesis of several rhenium con jugates takes advantage of the specificity of N-succinimidyl esters fo r amino residues. Conjugation experiments were carried out under vario us conditions, and analysis of the conjugates was performed by FT-IR s pectroscopy. Yields were optimized and reached 50%. Furthermore, the c onjugate resulting from the coupling of N-succinimidyl 4-[eta5-cyclope ntadienylrhenium tricarbonyl] 4-oxobutanoate to an anti-hTSH monoclona l antibody retained a satisfactory immunoreactivity. Finally, IR detec tion of conjugates adsorbed onto nitrocellulose membranes was achieved and response was found to be related to the coupling extent of the co njugate.