Activator-associated Ca2+-ATPase in erythrocyte membranes from cystic fibrosis patients.
Erythrocyte membranes were prepared by a method which should ensure binding of an activator protein (calmodulin) to the calcium dependent membrane ATPase involved in calcium transport. The level of enzyme activity, assayed at optimum conditions, was 5-400 times higher than that found in previous investigations on cystic fibrosis patients. The Ca2+-ATPase activity of the cystic fibrosis patients was reduced by 15% compared to control subjects, whereas patients suffering from chronic pulmonary diseases did not deviate from controls. Even if a reduction of Ca2+ pumping activity occurs in other cells, a 15% decrease could hardly be the only cause of the changed calcium concentrations in secretions from cystic fibrosis patients.
D000293:Adolescent; D000328:Adult; D002118:Calcium / Q000032:analysis; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000097:blood / Q000201:enzymology*; D004910:Erythrocyte Membrane / Q000201:enzymology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D000252:Calcium-Transporting ATPases; D002118:Calcium