( 3 ) the absence of correlation between the divalent cation selectivity properties of actin heavy meromyosin atpase controlled by cardiac troponin-tropomyosin and cardiac muscle tension or myofibrillar atpase activation by ca2+ and sr2+ suggests that troponin , if primarily responsible for the activation of cardiac muscle , has very different in vivo and in vitro binding properties .
C0001473
atpase
C0001476
atpase