The effect of anti-ATPase antibodies upon the Ca ++ transport of sarcoplasmic reticulum

Abstract

Sheep or guinea pig antisera against the purified Ca ++ transport ATPase of sarcoplasmic reticulum inhibit Ca ++ transport due to a complement-dependent damage of the membrane, which causes massive leakage of Ca ++. The Ca ++-activated ATPase activity is only slightly affected even at ten times higher antibody concentration than that required for inhibition of Ca ++ transport. Antibodies prepared against the Ca ++ binding protein (C 1 protein) have no influence upon either ATPase activity or Ca ++ transport and ferritin-labeled anti-C 1 antibodies do not bind to microsomes.