PMID: 9151Sep 21, 1976

The interaction of magnesium ions with the calcium pump of sarcoplasmic reticulum

Biochimica Et Biophysica Acta
P J GarrahanG L Alonso


1. In the presence of Ca2+, ATP phosphorylates the Ca2+ pump of sarcoplasmic reticulum at the same site and to the same extent regardless of whether Mg2+ is added or not to the incubation media, the main effect of added Mg2+ being to increase the rate of phosphorylation. 2. When phosphoenzyme is made in Mg2+-containing media it dephosphorylates about 30-times faster than when it is made in the absence of added Mg2+. Addition of Mg2+ after phosphorylation is uneffective in accelerating the hydrolysis of phosphoenzyme even in solubilized enzyme, suggesting that phosphorylation of the Ca2+ pump results in occlusion of the site at which Mg2+ combines to accelerate the release of phosphate. 3. Occlusion of the site for Mg2+ can be partially reversed by trans-1,2-diaminocyclohexonetetraacetic acid (CDTA). Use was made of this property to demonstrate that for the rapid release of phosphate to occur Mg2+ has to be bound to the enzyme. 4. Results seem to indicate that Mg2+ combines with the Ca2+ pump prior to phosphorylation.


Jul 24, 1975·The Journal of Membrane Biology·A F Rega, P J Garrahan
Apr 16, 1973·Biochimica Et Biophysica Acta·G Meissner


Dec 1, 1987·Journal of Bioenergetics and Biomembranes·A G Lee
Oct 31, 1980·The Journal of Membrane Biology·V C Chiu, D H Haynes
Jun 8, 2001·The Biochemical Journal·A G Lee, J M East
Nov 1, 1979·Archives of Biochemistry and Biophysics·G L AlonsoS Terradas de Fermani
May 1, 1981·Archives of Biochemistry and Biophysics·M Chiesi, G Inesi
Nov 8, 1996·Biochimica Et Biophysica Acta·D Takara, G L Alonso
Jan 15, 1986·European Journal of Biochemistry·C R Fleschner, N Kraus-Friedmann
Jan 1, 1982·Annals of the New York Academy of Sciences·J T Penniston

Related Concepts

Acetic Acids
DNA-dependent ATPase
Adenosine Triphosphate, Chromium Ammonium Salt
Hydrogen-Ion Concentration
Sarcoplasmic Reticulum

Related Feeds

B-Cell Lymphoma

B-cell lymphomas include lymphomas that affect B cells. This subtype of cancer accounts for over 80% of non-Hodgkin lymphomas in the US. Here is the latest research.

Blood And Marrow Transplantation

The use of hematopoietic stem cell transplantation or blood and marrow transplantation (bmt) is on the increase worldwide. BMT is used to replace damaged or destroyed bone marrow with healthy bone marrow stem cells. Here is the latest research on bone and marrow transplantation.