The Journal of Membrane Biology

, Volume 41, Issue 4, pp 361–376 | Cite as

On the red blood cell Ca2+-pump: An estimate of stoichiometry

  • F. L. Larsen
  • T. R. Hinds
  • F. F. Vincenzi


Efflux of Ca2+ from reversibly hemolyzed human red blood cell ghosts was determined by a Ca2+ selective electrode, by atomic absorption spectroscopy, and by the use of45Ca. Hydrolysis of ATP was determined by measurement of inorganic phosphate (Pi). At 25°C, ghosts loaded with CaCl2, MgCl2, Na2ATP, and Tris buffer (pH 7.4) extruded Ca2+, with mean rates ranging from 58.8±3.5 (sd) to 74.7±8.2 (sd) μmoles·liter ghosts−1·min depending on the method of Ca2+ determination. The ratio of Ca2+ transported to Pi released in the presence of ouabain without correction for background ATP splitting was 0.83, 0.83, and 0.80, respectively, for the three methods of Ca2+ determination. Correction for the ATPase activity not associated with Ca2+ transport resulted in a ratio of 0.91:1. In other experiments, the use of La3+ to inhibit the Ca2+-pump allowed an estimate of the ATPase activity associated with Ca2+ extrusion. In the presence of various concentrations of La3+, the ratio of Ca2+ pumped to Pi liberated was 0.86 or 1.02, depending on the method of Ca2+ determination. It is concluded that the stoichiometry of the Ca2+-pump of the RBC plasma membrane is one Ca2+ pumped per ATP hydrolyzed.


Inorganic Phosphate Plasma Membrane MgCl2 CaCl2 Human Physiology 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bygrave, F.L. 1966. The effects of calcium ions on the glycolytic activity of Ehrlich ascitestumour cells.Biochem. J. 101:480PubMedGoogle Scholar
  2. Duhn, J., Deuticke, B., Gerlach, E. 1968. Metabolism of 2,3-diphosphoglycerate and glycolysis in human red blood cells under the influence of dipyridamole and inorganic sulfur compounds.Biochim. Biophys. Acta 170:452PubMedGoogle Scholar
  3. Fiske, C.H., SubbaRow, Y. 1925. The colorimetric determination of phosphorus.J. Biol. Chem. 66:375Google Scholar
  4. Gilman, A., Philips, F.S., Koelle, E.S., Allen, R.P., St. John, E. 1946. The metabolic reduction and nephrotoxic action of tetrathionate in relation to a possible interaction with sulfhydryl compounds.Am. J. Physiol. 147:115Google Scholar
  5. Larsen, F.L., Vincenzi, F.F. 1977. Lanthanum inhibition of plasma membrane calcium transport.Proc. West. Pharmacol. Soc. 20:319PubMedGoogle Scholar
  6. Lee, K.S., Shin, B.C. 1969. Studies on the active transport of calcium in human red cells.J. Gen. Physiol. 54:713PubMedGoogle Scholar
  7. Madeira, V.M.C. 1975. A rapid and ultrasensitive method to measure Ca++ movements across biological membranes.Biochem. Biophys. Res. Commun. 64:870PubMedGoogle Scholar
  8. Olson, E.J., Cazort, R.J. 1969. Active calcium and strontium transport in human erythrocyte ghosts.J. Gen. Physiol. 53:311PubMedGoogle Scholar
  9. Quist, E.E., Roufogalis, B.D. 1975a. Determination of the stoichiometry of the calcium pump in human erythrocytes using lanthanum as a selective inhibitor.FEBS Lett. 50:135PubMedGoogle Scholar
  10. Quist, E.E., Roufogalis, B.D. 1975b. Calcium transport in human erythrocytes.Arch. Biochem. Biophys. 168:240PubMedGoogle Scholar
  11. Roy, A.B., Trudinger, P.A. 1970. The Biochemistry of Inorganic Compounds of Sulphur. Ch. 2, p. 19. Cambridge University Press, LondonGoogle Scholar
  12. Sarkadi, B., Szász, I., Gárdos, G. 1976. The use of ionophores of rapid loading of human red cells with radioactive cations for cation-pump studies.J. Membrane Biol. 26:357Google Scholar
  13. Sarkadi, B., Szász, I., Gerlóczy, A., Gárdos, G. 1977. Transport parameters and stoichiometry of active calcium ion extrusion in intact human red cells.Biochim. Biophys. Acta 464:93PubMedGoogle Scholar
  14. Schatzmann, H.J. 1966. ATP-dependent Ca++ extrusion from human red cells.Experientia 22:364PubMedGoogle Scholar
  15. Schatzmann, H.J. 1973. Dependence on calcium concentration and stoichiometry of the calcium pump in human red cells.J. Physiol. (London) 235:551Google Scholar
  16. Schatzmann, H.J. 1975. Active calcium transport and Ca2+-activated ATPase in human red cells.In: Current Topics in Membranes and Transport. F. Bronner and A. Kleinzeller, editors. p. 125. Academic Press, New YorkGoogle Scholar
  17. Schatzmann, H.J., Vincenzi, F.F. 1969. Calcium movements across the membrane of human red cells.J. Physiol. (London) 201:369Google Scholar
  18. Trudinger, P.A. 1965. Effect of thiol-binding reagents on the metabolism of thiosulfate and tetrathionate byThiobacillus neapolitanus.J. Bacteriol. 89:617PubMedGoogle Scholar
  19. Wolf, H.U. 1972. Studies on the Ca2+-dependent ATPase of human erythrocyte membranes. Effects of Ca2+ and H+.Biochim. Biophys. Acta 266:361PubMedGoogle Scholar

Copyright information

© Springer-Verlag New York Inc. 1978

Authors and Affiliations

  • F. L. Larsen
    • 1
  • T. R. Hinds
    • 1
  • F. F. Vincenzi
    • 1
  1. 1.Department of Pharmacology, School of MedicineUniversity of WashingtonSeattle

Personalised recommendations