title: The phospholipid requirement of the (Ca2+ + Mg2+)-ATPase from human platelets.
abstract: The phospholipid requirement of the (Ca2+ + Mg2+)-ATPase present in a membrane fraction from human platelets was studied using various purified phospholipases. Only those phospholipases, which hydrolyse the negatively charged phospholipids, inhibited the (Ca2+ + Mg2+)-ATPase activity. The ATPase activity could be restored by adding mixed micelles of Triton X-100 and phosphatidylserine or phosphatidylinositol. Micelles with phosphatidic acid, phosphatidylcholine, phosphatidylethanolamine or sphingomyelin could not be used for reconstitution and inhibited the activity of the native enzyme.
mesh_terms: D000251:Adenosine Triphosphatases / Q000097:blood; D001792:Blood Platelets / Q000201:enzymology*; D017301:Ca(2+) Mg(2+)-ATPase; D002118:Calcium / Q000494:pharmacology; D000252:Calcium-Transporting ATPases / Q000097:blood*; D006801:Humans; D010740:Phospholipases / Q000097:blood; D010743:Phospholipids / Q000097:blood*; D013997:Time Factors
chemical_list: D010743:Phospholipids; D010740:Phospholipases; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases; D002118:Calcium