Superoxidedismutase, catalase, peroxidase, and peroxide-independent oxidoreductase activities of IgG antibodies from the blood of Wistar rata
Electrophoretically and immunologically homogeneous IgG preparations were obtained from healthy Wistar rats by affinity chromatography on Protein A-Sepharose and following gel filtration. A comparison of catalase, superoxidedismutase (SOD), Н <sub>2</sub>О <sub>2</sub>-dependent peroxidase, and Н <sub>2</sub>О <sub>2</sub>-independent oxidoreductase activities of polyclonal IgGs have been carried for the first time. Five of six IgGs possess by SOD activity, while all preparations oxidized 3,3'-diaminobenzi-dine (DAB) in the presence and in the absence of hydrogen peroxide. It was shown that only one IgG preparation had catalase activity. The relative SOD, peroxidase, and oxidoreductase activities of IgGs can differ depending of rat 1.0 - 2.6-fold. On average the rate of IgG-dependent conversion of superoxide radical to water and oxygen (SOD-activity) was several orders of magnitude lower than that for oxidation of DAB. An addition of metal ions (Cu <sup>2</sup>+ + Mn <sup>2</sup> or Cu <sup>2</sup>+ + Zn <sup>2</sup>) led to increase in the rate of DAB oxidation by 1.2 - 6-fold. A possible biological role and nature of origin of abzymes with oxidative-reductive activities are discussed.