Ca2+ -calmodulin-dependent phosphorylation and platelet secretion

Abstract

Non-muscle actomyosin e.g., that isolated from [human] platelets may be regulated by Ca2+-calmodulin-dependent L chain phosphorylation, but the precise relationship between phosphorylation and the function of platelets has not been clearly established. Pharmacological evidence that a calmodulin-mediated system, such as Ca2+-dependent myosin L chain phosphorylation, plays an important role in the phenomenon of the release reaction is presented. N-(o-aminohexyl)-5-chloro-1-naphthalene-sulfonamide binds selectively to calmodulin in vitro and inhibits its biological activity.