Ca2+ binding and charge movements in membranes of platelets and sarcoplasmic reticulum
- 4 June 1984
- journal article
- Published by Wiley in FEBS Letters
- Vol. 171 (1) , 89-93
- https://doi.org/10.1016/0014-5793(84)80465-2
Abstract
The properties of the Ca2+‐pump system of platelet microsomes isolated without Ca2+‐precipitating anions are studied. Passive Ca2+ binding to the microsomes takes place in a noncooperative manner with K d = 0.7 μM. Half‐maximal stimulation of ATP‐dependent transport occurs at 0.4 μM Ca2+. The velocity of Ca2+ uptake, Ca2+ capacity and the level of phosphoprotein in platelet microsomes are significantly lower than in cardiac microsomes. Energization of platelet and muscle microsomes and activation of intact platelets result in opposite charge redistribution in hydrophobic regions of the membranes. It is concluded that these charge movements are caused by Ca2+ binding to and dissociation from nonpolar binding sites in the membranes.Keywords
This publication has 13 references indexed in Scilit:
- Structural and functional properties of a Ca2+-ATPase from human platelets.Journal of Biological Chemistry, 1982
- Changes in Cytoplasmic pH and in Membrane Potential in Thrombin-Stimulated Human PlateletsEuropean Journal of Biochemistry, 1981
- Myoplasmic free calcium concentration reached during the twitch of an intact isolated cardiac cell and during calcium-induced release of calcium from the sarcoplasmic reticulum of a skinned cardiac cell from the adult rat or rabbit ventricle.The Journal of general physiology, 1981
- Calcium-binding rate and capacity of cardiac sarcoplasmic reticulumJournal of Molecular and Cellular Cardiology, 1981
- Stimulation of calcium uptake in platelet membrane vesicles by adenosine 3′,5′-cyclic monophosphate and protein kinaseBiochimica et Biophysica Acta (BBA) - Biomembranes, 1977
- Permeability of sarcoplasmic reticulum membrane. The effect of changed ionic environments on Ca2+ releaseThe Journal of Membrane Biology, 1976
- Direct evidence for intracellular divalent cation redistribution associated with platelet shape changeBiochemical and Biophysical Research Communications, 1976
- Calcium Uptake and Associated Adenosine Triphosphatase Activity of Isolated Platelet MembranesThe Journal of general physiology, 1973
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970
- Conversion of biomembrane-produced energy into electric form. I. Submitochondrial particlesBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1970