[Effect of myosin and its fragments on some creatine kinase properties].

Some properties of creatine kinase were investigated in a two-enzyme system, myosin ATPase-creatine kinase. A rise in the creatine activity in the presence of native myosin was demonstrated. The addition of proteolytic fragments of myosin caused a similar effect. Thermostability of creatine kinase in the presence of native myosin increased. Blocking of amino groups of myosin by TNBS had no effect on its activating capacity, but decreased its influence on thermostability of creatine kinase. Localization of the binding sites of creatine kinase on the myosin molecule is discussed in the present work.