Inhibition of actin-myosin subfragment 1 ATPase activity by troponin I and IC: relationship to the thin filament states of muscle.

Troponin I (TnI) is the component of the troponin complex that inhibits actomyosin ATPase activity, and Ca(2+) binding to the troponin C (TnC) component reverses the inhibition. Effects of the binding of TnI and the TnI-TnC (TnIC) complex to actin-tropomyosin (actinTm) on ATPase and on the binding kinetics of myosin subfragment 1 (S1) were studied to… (More)