Effects of phospholipids on binding of calcium to (Ca2(+)-Mg2(+)-ATPase.
The (Ca2(+)-Mg2(+)-ATPase purified from skeletal muscle sarcoplasmic reticulum binds two Ca2+ ions per ATPase molecule. On reconstitution into bilayers of dioleoylphosphatidylcholine [C18:1)PC) or dinervonylphosphatidylcholine [C24:1)PC) the stoichiometry of binding remains unchanged, but when the ATPase is reconstituted into bilayers of dimyristoleoylphosphatidylcholine [C14:1)PC) the stoichiometry changes to one Ca2+ ion per ATPase molecule. Nevertheless, the level of phosphorylation is the same for the ATPase reconstituted with (C18:1)PC or (C14:1)PC. The effect of (C14:1)PC on the stoichiometry of Ca2+ binding is prevented by androstenol at a 1:1 molar ratio with the phospholipid.
Michelangeli
F
F
Department of Biochemistry, University of Southampton, U.K.
Orlowski
S
S
Champeil
P
P
Grimes
E A
EA
East
J M
JM
Lee
A G
AG
D000737:Androstenols / Q000494:pharmacology; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D004134:Dimyristoylphosphatidylcholine / Q000494:pharmacology; D008051:Lipid Bilayers; D008563:Membrane Lipids / Q000494:pharmacology*; D010713:Phosphatidylcholines / Q000494:pharmacology; D010743:Phospholipids / Q000494:pharmacology*; D010766:Phosphorylation; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation / Q000187:drug effects; D011817:Rabbits
D000737:Androstenols; D008051:Lipid Bilayers; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D010743:Phospholipids; C066558:dinervonylphosphatidylcholine; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases; C017251:1,2-oleoylphosphatidylcholine; D002118:Calcium; D004134:Dimyristoylphosphatidylcholine