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. 1990 Apr 15;267(2):423–429. doi: 10.1042/bj2670423

Effect of pH on the activity of the Ca2+ + Mg2(+)-activated ATPase of sarcoplasmic reticulum.

F Michelangeli 1, J Colyer 1, J M East 1, A G Lee 1
PMCID: PMC1131306  PMID: 2139777

Abstract

A kinetic model for the Ca2(+) + Mg2(+)-activated ATPase of sarcoplasmic reticulum was presented in a previous paper [Stefanova, Napier, East & Lee (1987) Biochem. J. 245, 723-730]. Here, that model is modified to account for the pH-dependence of ATPase activity and for the effects of Mg2+ on activity at high pH. It is shown that effects of Mg2+ on measurements of ATPase activity as a function of ATP concentration at pH 8.0 and pH 8.5 are consistent with binding of Mg2+ to the Ca2(+)-binding sites on the phosphorylated ATPase, such binding inhibiting dephosphorylation of the ATPase. It is also shown that slow dissociation of Ca2+ from the phosphorylated ATPase is consistent with the previously published model.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bishop J. E., Al-Shawi M. K. Inhibition of sarcoplasmic reticulum Ca2+-ATPase by Mg2+ at high pH. J Biol Chem. 1988 Feb 5;263(4):1886–1892. [PubMed] [Google Scholar]
  2. Cha S. A simple method for derivation of rate equations for enzyme-catalyzed reactions under the rapid equilibrium assumption or combined assumptions of equilibrium and steady state. J Biol Chem. 1968 Feb 25;243(4):820–825. [PubMed] [Google Scholar]
  3. Champeil P., Guillain F. Rapid filtration study of the phosphorylation-dependent dissociation of calcium from transport sites of purified sarcoplasmic reticulum ATPase and ATP modulation of the catalytic cycle. Biochemistry. 1986 Nov 18;25(23):7623–7633. doi: 10.1021/bi00371a053. [DOI] [PubMed] [Google Scholar]
  4. Dupont Y. Low-temperature studies of the sarcoplasmic reticulum calcium pump. Mechanisms of calcium binding. Biochim Biophys Acta. 1982 May 21;688(1):75–87. doi: 10.1016/0005-2736(82)90580-6. [DOI] [PubMed] [Google Scholar]
  5. Dupont Y. Occlusion of divalent cations in the phosphorylated calcium pump of sarcoplasmic reticulum. Eur J Biochem. 1980 Aug;109(1):231–238. doi: 10.1111/j.1432-1033.1980.tb04788.x. [DOI] [PubMed] [Google Scholar]
  6. Fernandez-Belda F., Inesi G. Transmembrane gradient and ligand-induced mechanisms of adenosine 5'-triphosphate synthesis by sarcoplasmic reticulum adenosinetriphosphatase. Biochemistry. 1986 Dec 2;25(24):8083–8089. doi: 10.1021/bi00372a043. [DOI] [PubMed] [Google Scholar]
  7. Fernandez-Belda F., Kurzmack M., Inesi G. A comparative study of calcium transients by isotopic tracer, metallochromic indicator, and intrinsic fluorescence in sarcoplasmic reticulum ATPase. J Biol Chem. 1984 Aug 10;259(15):9687–9698. [PubMed] [Google Scholar]
  8. Froud R. J., Lee A. G. A model for the phosphorylation of the Ca2+ + Mg2+-activated ATPase by phosphate. Biochem J. 1986 Jul 1;237(1):207–215. doi: 10.1042/bj2370207. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Froud R. J., Lee A. G. Conformational transitions in the Ca2+ + Mg2+-activated ATPase and the binding of Ca2+ ions. Biochem J. 1986 Jul 1;237(1):197–206. doi: 10.1042/bj2370197. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Gould G. W., Colyer J., East J. M., Lee A. G. Silver ions trigger Ca2+ release by interaction with the (Ca2+-Mg2+)-ATPase in reconstituted systems. J Biol Chem. 1987 Jun 5;262(16):7676–7679. [PubMed] [Google Scholar]
  11. Gould G. W., East J. M., Froud R. J., McWhirter J. M., Stefanova H. I., Lee A. G. A kinetic model for the Ca2+ + Mg2+-activated ATPase of sarcoplasmic reticulum. Biochem J. 1986 Jul 1;237(1):217–227. doi: 10.1042/bj2370217. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Gould G. W., McWhirter J. M., East J. M., Lee A. G. A model for the uptake and release of Ca2+ by sarcoplasmic reticulum. Biochem J. 1987 Aug 1;245(3):739–749. doi: 10.1042/bj2450739. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Inesi G., Hill T. L. Calcium and proton dependence of sarcoplasmic reticulum ATPase. Biophys J. 1983 Nov;44(2):271–280. doi: 10.1016/S0006-3495(83)84299-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Inesi G., Lewis D., Murphy A. J. Interdependence of H+, Ca2+, and Pi (or vanadate) sites in sarcoplasmic reticulum ATPase. J Biol Chem. 1984 Jan 25;259(2):996–1003. [PubMed] [Google Scholar]
  15. Khananshvili D., Jencks W. P. Two-step internalization of Ca2+ from a single E approximately P.Ca2 species by the Ca2+-ATPase. Biochemistry. 1988 Apr 19;27(8):2943–2952. doi: 10.1021/bi00408a041. [DOI] [PubMed] [Google Scholar]
  16. Pick U. The interaction of vanadate ions with the Ca-ATPase from sarcoplasmic reticulum. J Biol Chem. 1982 Jun 10;257(11):6111–6119. [PubMed] [Google Scholar]
  17. Pickart C. M., Jencks W. P. Energetics of the calcium-transporting ATPase. J Biol Chem. 1984 Feb 10;259(3):1629–1643. [PubMed] [Google Scholar]
  18. Rooney E. K., Lee A. G. Binding of hydrophobic drugs to lipid bilayers and to the (Ca2+ + Mg2+)-ATPase. Biochim Biophys Acta. 1983 Jul 27;732(2):428–440. doi: 10.1016/0005-2736(83)90060-3. [DOI] [PubMed] [Google Scholar]
  19. Scofano H., Barrabin H., Inesi G., Cohen J. A. Stoichiometric and electrostatic characterization of calcium binding to native and lipid-substituted adenosinetriphosphatase of sarcoplasmic reticulum. Biochim Biophys Acta. 1985 Sep 25;819(1):93–104. doi: 10.1016/0005-2736(85)90199-3. [DOI] [PubMed] [Google Scholar]
  20. Shigekawa M., Wakabayashi S., Nakamura H. Reaction mechanism of Ca2+-dependent adenosine triphosphatase of sarcoplasmic reticulum. ATP hydrolysis with CaATP as a substrate and role of divalent cation. J Biol Chem. 1983 Jul 25;258(14):8698–8707. [PubMed] [Google Scholar]
  21. Stahl N., Jencks W. P. Adenosine 5'-triphosphate at the active site accelerates binding of calcium to calcium adenosinetriphosphatase. Biochemistry. 1984 Nov 6;23(23):5389–5392. doi: 10.1021/bi00318a002. [DOI] [PubMed] [Google Scholar]
  22. Stahl N., Jencks W. P. Reactions of the sarcoplasmic reticulum calcium adenosinetriphosphatase with adenosine 5'-triphosphate and Ca2+ that are not satisfactorily described by an E1-E2 model. Biochemistry. 1987 Dec 1;26(24):7654–7667. doi: 10.1021/bi00398a019. [DOI] [PubMed] [Google Scholar]
  23. Stefanova H. I., Napier R. M., East J. M., Lee A. G. Effects of Mg2+, anions and cations on the Ca2+ + Mg2+-activated ATPase of sarcoplasmic reticulum. Biochem J. 1987 Aug 1;245(3):723–730. doi: 10.1042/bj2450723. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Wakabayashi S., Ogurusu T., Shigekawa M. Factors influencing calcium release from the ADP-sensitive phosphoenzyme intermediate of the sarcoplasmic reticulum ATPase. J Biol Chem. 1986 Jul 25;261(21):9762–9769. [PubMed] [Google Scholar]
  25. Wakabayashi S., Ogurusu T., Shigekawa M. Modulation of the hydrolysis rate of the ADP-insensitive phosphoenzyme of the sarcoplasmic reticulum ATPase by H+ and Mg2+. J Biol Chem. 1987 Jul 5;262(19):9121–9129. [PubMed] [Google Scholar]
  26. Yamada S., Fujii J., Katayama H. Sarcoplasmic reticulum Ca-ATPase: distinction of phosphoenzymes formed from MgATP and CaATP as substrates and interconversion of the phosphoenzymes by Mg2+ and Ca2+. J Biochem. 1986 Nov;100(5):1329–1342. doi: 10.1093/oxfordjournals.jbchem.a121839. [DOI] [PubMed] [Google Scholar]
  27. de Meis L., Vianna A. L. Energy interconversion by the Ca2+-dependent ATPase of the sarcoplasmic reticulum. Annu Rev Biochem. 1979;48:275–292. doi: 10.1146/annurev.bi.48.070179.001423. [DOI] [PubMed] [Google Scholar]

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