[18 O-exchange reactions catalyzed by subfragment 1 of myosin molecule]. / O18-obmennye reaktsii, kataliziruemye subfragmentom 1 molekuly miozina

18 O-exchange properties of enzymically active proteolytic fragment of myosin molecule--subfragment 1 were studied. It was shown that 18O-exchange activity of subfragment 1 is similar to that of parental myosin and its other proteolytic fragment--heavy meromyosin. The experimental data suggest that the 18O-exchange activity is an integral property of myosin and is not determined by its contaminations.