INHIBITION OF SOLUBILIZED SUPEROXIDE-DISMUTASE CO-IMMOBILIZED WITH CATALASE BY THE POLYDISULFIDE OF GALLIC ACID

The catalytic activity of superoxide dismutase (SOD) and its conjugate s with catalase and polymer peroxidase (p-peroxidase) obtained during covalent binding of enzymes with aldehyde dextrans was indirectly char acterized by inhibition of adrenaline autoxidation in 0.1 M bicarbonat e buffer, pH 10.2, and in microemulsion of 0.1 M aerosol OT (AOT) and Triton X-45 in octane containing 15% aqueous phase. The polydisulfide of gallic acid (PDGA) effectively inhibited SOD and its conjugates by a mixed mechanism. The inhibition constants K-i for SOD and its conjug ate (SOD-catalase)(mic) in 0.1 M bicarbonate buffer, pH 10.2, were 0.1 and 0.25 mu M, respectively. Autoxidation of PDGA by molecular oxygen in alkaline media (pH 10.2) influenced its inhibitory properties in b uffer solution and microemulsion of AOT and Triton X-45 in octane. The radical chain mechanism of co-oxidation of adrenaline and PDGA appare ntly includes the anion radical O-2(-) as a coupling agent which propa gated the chain.