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Oxidoreductase activities of polyclonal IgGs from the sera of Wistar rats are better activated by combinations of different metal ions
Author(s) -
Tolmacheva Anna S.,
Zaksas Nataliya P.,
Buneva Valenti.,
Vasilenko Nataliya L.,
Nevinsky Georgy A.
Publication year - 2008
Publication title -
journal of molecular recognition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.401
H-Index - 79
eISSN - 1099-1352
pISSN - 0952-3499
DOI - 10.1002/jmr.923
Subject(s) - oxidoreductase , chemistry , peroxidase , polyclonal antibodies , metal , metal ions in aqueous solution , ion , enzyme , biochemistry , nuclear chemistry , antibody , immunology , biology , organic chemistry
It was shown that IgGs purified from the sera of healthy Wistar rats contain several different bound Me 2+ ions and oxidize 3,3′‐diaminobenzidine through a H 2 O 2 ‐dependent peroxidase and H 2 O 2 ‐independent oxidoreductase activity. IgGs have lost these activities after removing the internal metal ions by dialysis against EDTA. External Cu 2+ or Fe 2+ activated significantly both activities of non‐dialysed IgGs containing different internal metals (Fe ≥ Pb ≥ Zn ≥ Cu ≥ Al ≥ Ca ≥ Ni ≥ Mn > Co ≥ Mg) showing pronounced biphasic dependencies corresponding to ∼0.1–2 and ∼2–5 mM of Me 2+ , while the curves for Mn 2+ were nearly linear. Cu 2+ alone significantly stimulated both the peroxidase and oxidoreductase activities of dialysed IgGs only at high concentration (≥ 2 mM), while Mn 2+ weakly activated peroxidase activity at concentration >3 mM but was active in the oxidoreductase oxidation at a low concentration (<1 mM). Fe 2+ ‐dependent peroxidase activity of dialysed IgGs was observed at 0.1–5 mM, but Fe 2+ was completely inactive in the oxidoreductase reaction. Mg 2+ , Ca 2+ , Zn 2+ , Al 2+ and especially Co 2+ and Ni 2+ were not able to activate dialysed IgGs, but slightly activated non‐dialysed IgGs. The use of the combinations of Cu 2+ + Mn 2+ , Cu 2+ + Zn 2+ , Fe 2+ + Mn 2+ , Fe 2+ + Zn 2+ led to a conversion of the biphasic curves to hyperbolic ones and in parallel to a significant increase in the activity as compared with Cu 2+ , Fe 2+ or Mn 2+ ions taken separately; the rates of the oxidation reactions, catalysed by non‐dialysed and dialysed IgGs, became comparable. Mg 2+ , Co 2+ and Ni 2+ markedly activated the Cu 2+ ‐dependent oxidation reactions catalysed by dialysed IgGs, while Ca 2+ inhibited these reactions. A possible role of the second metal in the oxidation reactions is discussed. Copyright © 2008 John Wiley & Sons, Ltd.