DISSOCIATION AND REASSOCIATION OF CREATINE-KINASE WITH HEART-MITOCHONDRIA - PH AND PHOSPHATE DEPENDENCE

Experimental evidence is given of mitochondrial creatine kinase ability to dissociate from or reassociate with mitochondrial membrane as compared to the behaviour of adenylate kinase. CK release occurs for Pi concentrations higher than 5 mM and is strongly pH-dependant. Solubilized CK is able to reassociate with mitochondrial inner membrane when either Pi concentration or pH are decreased. The possible physiological effects of events, such as ischemia, which modify the intracellular pH or Pi concentration are discussed, in view of the special role which has been attributed to mitochondrial CK in the transfer of energy in heart cells. © 1979.