Polyhydric Alcohols Mediated Inhibition of Calcium Activated Adenosine Triphosphatase Activity of Fish Skeletal Muscle Actomyosin.

Actomyosin isolated from fish varied from other vertebrate actomyosin. Ca 2+ ATPase activity of fish actomyosin showed the maximum activity at pH 9.0. The enzyme activity decreased with increase in temperature. Polyhydric alcohols, such as sorbitol and mannitol, inhibited the Ca 2+ ATPase activity of fish actomyosin. Mannitol was more potent inhibitor of the activity than sorbitol. An amount of 0.2M of mannitol and 0.3M of sorbitol in solution completely inhibited the Ca 2+ ATPase activity. The reduction in the intrinsic fluorescence intensity of actomyosin was insignificant in presence of these polyols. The inhibition of actomyosin Ca 2+ ATPase activity is associated with reduction in the free SH content. Secondary structure of actomyosin recorded a marginal increase in the α-helicity in presence of these polyols. These polyols reduced the nucleotide degrading property of actomyosin without alteration in the structure of molecules. [ABSTRACT FROM AUTHOR]