Purification and phosphate content of slow-twitch human myosin and its possible role in the maintenance of muscle function.
In the present study the phosphate content of a slow-twitch human muscle myosin was investigated and compared with other myosins. It was found that, similar to myosin of the skeletal muscle of the rabbit, the total and labile phosphate content of this human myosin varied depending on the load previously imposed on the muscle. The labile phosphate content thought to be important in the course of contraction ranged between 4 and 8 mol, which might be explained by the different load applied on the preparations in study. These data were compared with those obtained in a fast-twitch human myosin and the changes in its phosphate content appeared to support the hypothesis put forward on the basis of recent studies on slow-twitch myosin.
D000328:Adult; D000368:Aged; D000818:Animals; D006801:Humans; D008875:Middle Aged; D008970:Molecular Weight; D009043:Motor Activity / Q000502:physiology; D009119:Muscle Contraction; D009132:Muscles / Q000502:physiology*; D009218:Myosins / Q000302:isolation & purification / Q000502:physiology*; D010710:Phosphates / Q000032:analysis / Q000502:physiology*; D011817:Rabbits
D010710:Phosphates; D009218:Myosins