[Co-oxidation of phenols and 4-aminoantipyrene catalyzed by microperoxidase and their complexes with proteins].

: The kinetic parameters of 4-aminoantipyrine (AAP) co-oxidation with phenol or p-iodophenol in a wide range of hydrogen peroxide concentrations were compared for microperoxidases MP-8, MP-9, MP-11, horseradish peroxidase (HRP) and peroxidase of Arthromyces ramosus (PAR). The peroxidatic activity increased in the following order: HRP > PAR > MP-9 > MP-8 > MP-11. Microperoxidase complexes with human serum albumin (1:1) retained their peroxidatic activity at high H2O2 concentrations, protecting haem from destruction by active radicals. Monoclonal antibodies against porphyrin decreased the peroxidatic activities of three microperoxidases during co-oxidation of AAP and phenol and protected haem. Inert proteins (BSA, ovalbumin) had little effect on the HRP activity, whereas enzyme-specific antibodies strongly activated HRP at high concentrations of hydrogen peroxide, thereby forming an immune complex protecting HRP from its dissociation down to haem and the apoenzyme.