... 116–131). In the relaxed state, the inhibitory region binds to actin and inhibits actin–myosin interaction [11,12],while in the contractile state, Ca2+-binding to site I and ⁄ or II of TnC causes the ... induces the dissociation of the inhibitory region,which is adjacent to the regulatory TnC-binding site,from actin, resulting in the release of the inhibition and muscle contraction [17]. The structural ... TnC-binding site and the C-domain of TnC accompanyingCa2+binding to site IV of TnC. In vertebrate tropo-nin, the activation may be a result of the interactionbetween the inhibitory region and...