[Role of individual phospholipids in the functional activity of human myocardial creatine kinase].

Regulating effect of individual phospholipids on the activity of creatine kinase MM from human myocardium was studied. Cardiolipin, phosphatidic acid, phosphatidyl serine and phosphatidyl choline (dipalmitoyl) stimulated the enzymatic activity, while phosphatidyl inositol and lysophosphatidyl choline inhibited the creatine kinase MM activity by 80-100%. When mechanisms of the phospholipids inhibitory effects were studied, mixed type of inhibition was detected in the presence of phosphatidyl inositol and non-competitive type--in presence of lysophosphatidyl choline if guanidine was used as a substrate. Phosphatidyl inositol and lysophosphatidyl choline inhibited creatine kinase MM by the uncompetitive type if ADP was used as a substrate.