Activation of the binding of C1q to immune complexes by zinc.
ZnSO4 promotes the binding of C1q to immune complexes over the same concentration range (10(-5)-10(-4) M) that it inhibits binding of C1 to cell-bound immunoglobulin [Biochem. Biophys. Res. Commun. (1981) 103, 856-862]. At higher concentrations (10(-3)-2 X 10(-2) M) ZnSO4 inhibited the binding of C1q to immune complexes, [Ki = (6 +/- 2) X 10(-3) M]. This inhibition could be correlated with a ZnSO4-induced change in the tryptophan fluorescence of C1q [delta F 25%, Kd = (9.9 +/- 1.0) X 10(-3) M].
D000936:Antigen-Antibody Complex / Q000378:metabolism*; D003166:Complement Activating Enzymes / Q000378:metabolism*; D003167:Complement Activation / Q000187:drug effects; D015922:Complement C1q; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013431:Sulfates / Q000494:pharmacology*; D015032:Zinc / Q000494:pharmacology*; D019287:Zinc Sulfate
D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D013431:Sulfates; D019287:Zinc Sulfate; D015922:Complement C1q; D003166:Complement Activating Enzymes; D015032:Zinc