PEROXIDATION OF PYROGALLOL BY ANTIBODY-METALLOPORPHYRIN COMPLEXES

Antibody 03-1, which was prepared by immunization with meso-tetrakis(4 -carboxyphenyl)porphyrin (TCPP) conjugate, has been found to bind stro ngly to Mn(III)-TCPP and Fe(III)-TCPP complexes with dissociation cons tants of 4.1 x 10(-7) and 1.5 x 10(-7) M, respectively, although other monoclonal antibodies raised against TCPP did not bind to these TCPP- metal complexes. The complexes of antibody 03-1 with Mn(III)-TCPP and Fe(III)-TCPP were found to catalyze oxidation of pyrogallol selectivel y. A Lineweaver-Burk plot for the oxidation of pyrogallol by the antib ody-Fe-TCPP complex showed K-m = 4.0 mM and k(cat) = 50 min(-1). Studi es on the effect of the molar ratio of the antibody to metalloporphyri n on the catalytic activity showed that a 1:1 complex was the most eff ective for the reaction. The effect of salt (NaCl) on the reaction sho wed that electrostatic interaction between the antibody and the metall oporphyrin was important for the reaction. The antibody-metalloporphyr in complexes are stable enough to show catalytic activity in the prese nce of an excess amount of H2O2.