Purification of a water-soluble Mg2+-ATPase from human erythrocyte membranes.
A water-soluble Mg2+-ATPase previously reported (White, M.D. and Ralston, G.B. (1976) Biochim. Biophys. Acta 436, 567-576) has been purified from human erythrocyte membranes. The purified enzyme has a molecular weight of 575 000; the apparent minimum molecular weight was 100 000, corresponding to a soluble protein of the component 3 region. The Km value for ATP was 1 mM and apparent Km for Mg2+ was 3.6 mM. By means of histochemical activity staining in acrylamide gels it was shown that the purified ATPase preparation could be inhibited by Cd2+ and Zn2+ salts, p-chloromercuribenzoate and N-ethylmaleimide, known inhibitors of membrane endocytosis.
D000251:Adenosine Triphosphatases / Q000097:blood* / Q000302:isolation & purification; D017301:Ca(2+) Mg(2+)-ATPase; D002104:Cadmium / Q000494:pharmacology; D002729:Chloromercuribenzoates / Q000494:pharmacology; D004705:Endocytosis / Q000187:drug effects; D004910:Erythrocyte Membrane / Q000201:enzymology*; D004912:Erythrocytes / Q000201:enzymology*; D005033:Ethylmaleimide / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D012995:Solubility; D015032:Zinc / Q000494:pharmacology
D002729:Chloromercuribenzoates; D002104:Cadmium; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D015032:Zinc; D005033:Ethylmaleimide