The effect of cholera toxin on human red cell Ca-ATPase.
The effect of cholera toxin on transport Ca-ATPase was studied in membrane fragments from human red cells. A consistently moderate inhibition was found when fragments were previously incubated with toxin in the presence of beta-NAD but not in its absence of after treatment with non-activated toxin. In calmodulin-free preparations, both Ca affinity and maximal rate of hydrolysis were affected whereas only affinity was altered in calmodulin-deficient membranes.
Romero
P J
PJ
Centro Biología Celular, Fac. Ciencias, UCV, Caracas, Venezuela.
Weitzman
C
C
D017301:Ca(2+) Mg(2+)-ATPase / Q000097:blood; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000097:blood*; D002772:Cholera Toxin / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000201:enzymology*; D006801:Humans; D007700:Kinetics
D002772:Cholera Toxin; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases