A Study of Certain Properties of Myosin from Skeletal Muscle

SUMMARY— This investigation was conducted (a) to establish a procedure for purifying a stable myosin preparation from pig skeletal muscle and (b) to evaluate the enzymatic activity and associated characteristics of purified myosin, isolated at death from skeletal muscles which ultimately have varying rates of hydrolysis of ATP in situ during the first half‐hour after death. Rabbit muscles were also used for comparative purposes. Myosin preparations were found to be pure (by ultracentrifugation, Sephadex separation and superprecipitation tests) and stable with normal values for SH groups. The Ca ++ ‐activated ATPase activities of myosin extracted from PSE Poland China pigs were significantly greater than those from Chester White pigs and normal Poland China pigs. EDTA‐activated ATPase activities were greater in myosin from PSE Poland China than in normal Poland China.