关键词: 铜－锌超氧化物歧化酶, 极谱法, 伏安法

Abstract: The superoxide radical ion O₂^－, intermediate in the reduction of molecular oxygen, is directly or indirectly involved in a series of biochemical reactions and biological phenomena such as lipid peroxidation, enzymatic hydroxylation, bacteralkilling. An overproduction of superoxide radicals is considered as the origin of some inflammator diseases. Superoxide dismutase (SOD) which has a high specific activity for dismutation of superoxide radicals, O₂^－, might play a significant, even vital, role in protecting the organism against damaging effects of the superoxide radical. In this paper, Cu-Zn-SODwas firstly studied by kinds of electroanalytical methods such as DCP, NPP, ACPand CV. DCpolarogram of SODin phosphate buffer solution ( pH7.0) shows two waves, whose half-wave potentials are of-0.63 Vand-1.03 V, respectively, in the potential range of-0.3 Vto-1.3V.The diffusion coefficient of SODobtained by Ilkoviv equation is 1.7×10^-6cm²/s (25℃). The electrode reaction corresponding to the wave at -0.63 Vis reversible. There are no current response observed at the conventional solid electrode such as glass carbon electrode, graphite electrode and platinum electrode.

Key words: Cu-Zn superoxide dismutase, Polarography, Voltammetry