Summary
(Ca2++Mg2+)-stimulated ATPase of human red cell membranes as a function of ATP concentration was measured at fixed Ca2+ concentration and at two different but constant Mg2+ concentrations. Under the assumption that free ATP rather than Mg-ATP is the substrate, a value forK m (for ATP) of 1–2μm is found which is in good agreement with the value obtained in the phosphorylation reaction by A.F. Rega and P.J. Garrahan (1975.J. Membrane Biol. 22:313). Mg2+ increases both the maximal rate and the affinity for ATP, whereas Ca2+ increases the maximal rate without affectingK m for ATP.
As a by-product of these experiments, it was shown that after thorough removal of intracellular proteins the adenylate kinase reaction at approximately 1mm substrate concentration is several times faster than maximal rate of (Ca2++Mg2+)-ATPase in red cell membranes.
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References
Berenblum, J., Chain, F. 1938. Studies on the colorimetric determination of phosphate.Biochem. J. 32:286
Bergmeyer, H.U. (Editor) 1970. Methoden der enzymatischen Analyse. 2. Aufl., p. 447. Verlag Chemie, Weinheim
Dunham, E.T., Glynn, I.M. 1961. Adenosinetriphosphatase activity and the active movements of alkali metal cations.J. Physiol. (London) 156:274
Feldhaus, P., Fröhlich, T., Goody, R., Isakov, M., Schirmer, R.H. 1975. Synthetic inhibitors of adenylate kinases in the assay for ATPases and phosphokinases.Eur. J. Biochem. 57:197
Knauf, P.A., Proverbio, F., Hoffman, J.F. 1974. Electrophoretic separation of different phosphoproteins associated with Ca-ATPase and Na−K-ATPase in human red cell ghosts.J. Gen. Physiol. 63:324
Lowry, D.H., Rosebrough, N.J., Farr, A.L., Randall, R.J. 1951. Protein measurement with the Folin phenol reagent.J. Biol. Chem. 193:265
Markland, F.S., Wadkins, Ch.L. 1966. Adenosinetriphosphate-adenosine-5′-monophosphotransferase of bovine liver mitochondria.J. Biol. Chem. 241:4136
Rega, A.F., Garrahan, P.J. 1975. Calcium ion-dependent phosphorylation of human erythrocyte membranes.J. Membrane Biol. 22:313
Schatzmann, H.J. 1967. Ca-activated membrane ATPase in human red cells and its possible role in active Ca transport.In: Protides Biol. Fluids. H. Peeters, editor.Proc. Colloq. 15:251. Elsevier, Amsterdam
— 1969. Transmembrane calcium movements in resealed human red cells.In: Calcium and Cellular Function A.W. Cuthbert, Editor. pp. 85–95. Macmillan, New York
Schatzmann, H.J., Vincenzi, F.F. 1969. Calcium movements across the membrane of human red cells.J. Physiol. (London) 201:369
Sen, A.K., Post, R.L. 1964. Stoichiometry and localization of adenosinetriphosphate dependent sodium and potassium transport in the erythrocyte.J. Biol. Chem. 239:345
Wins, T., Schoffeniels, S. 1966. Studies on red cell ghost ATPase system. Properties of a Mg2++Ca2+ dependent ATPase.Biochim. Biophys. Acta 120:341
Wolf, H.U. 1972. Studies on a Ca2+ dependent ATPase of human erythrocyte membranes. Effects of Ca2+ and H+.Biochim. Biophys. Acta 266:361
— 1973. Divalent metal ion buffers with low pH-sensitivity.Experientia 29:241
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Schatzmann, H.J. Role of magnesium in the (Ca2++Mg2+)-stimulated membrane ATPase of human red blood cells. J. Membrain Biol. 35, 149–158 (1977). https://doi.org/10.1007/BF01869946
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DOI: https://doi.org/10.1007/BF01869946