Structure of the NH2-terminal variable region of cardiac troponin T determines its sensitivity to restrictive cleavage in pathophysiological adaptation

► The NH2-terminal variable region of cardiac troponin T is a regulatory structure. ► Its removal has a compensatory effect on heart function in energetic crisis. ► Calcium overload conditions induced this restrictive proteolysis. ► The NH2-terminal structure of cardiac troponin forms a basis of this cleavage. ► Molecular conformation of the cleavage site may play a determining role.