IgG abzymes with peroxidase and oxidoreductase activities from the sera of healthy humans |
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| Authors: | Anna S. Tolmacheva Elena A. Blinova Evgeny A. Ermakov Valentina N. Buneva Nataliya L. Vasilenko Georgy A. Nevinsky |
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| Affiliation: | 1. Siberian Division of Russian Academy of Sciences, Institute of Cytology and Genetics, Novosibirsk, Russia;2. Siberian Division of Russian Academy of Sciences, Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, Russia;3. Novosibirsk State University, Novosibirsk, Russia |
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| Abstract: | ![]()
We present the evidence showing that small fractions of electrophoretically homogeneous immunoglobulin G (IgGs) from the sera of healthy humans and their Fab and F(ab)2 fragments oxidize 3,3′‐diaminobenzidine through a peroxidase activity in the presence of H2O2 and through an oxidoreductase activity in the absence of H2O2. During purification on protein G‐Sepharose and gel filtration, the polyclonal IgGs partially lose the Me2+ ions. After extensive dialysis of purified Abs against agents chelating metal ions, the relative peroxidase activity decreased dependently of IgG analyzed from 100 to ~10–85%, while oxidoreductase activity from 100 to 14–83%. Addition of external metal ions to dialyzed and non‐dialyzed IgGs leads to a significant increase in their activity. Chromatography of the IgGs on Chelex non‐charged with Cu2+ ions results in the adsorption of a small IgG fraction bound with metal ions (~5%), while Chelex charged with Cu2+ ions bind additionally ~38% of the total IgGs. Separation of Abs on both sorbents results in IgG separation to many different subfractions demonstrating various affinities to the chelating resin and different levels of the specific oxidoreductase and peroxidase activities. In the presence of external Cu2+ ions, the specific peroxidase activity of several IgG subfractions achieves 20–27 % as compared with horseradish peroxidase (HRP, taken for 100%). The oxidoreductase activity of these fractions is ~4–6‐fold higher than that for HRP. Antioxidant enzymes such as superoxide dismutases, catalases, and glutathione peroxidases are known to represent critical defence mechanisms for preventing oxidative modifications of DNA, proteins, and lipids. Peroxidase and oxidoreductase activities of human IgGs could also play an important role in the protection of organisms from oxidative stress and toxic compounds. Copyright © 2015 John Wiley & Sons, Ltd. |
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| Keywords: | abzyme sera of healthy humans IgGs oxidoreductase activities |
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