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

Abstract

Actomyosin isolated from fish varied from other vertebrate actomyosin. Ca²⁺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 Ca²⁺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 Ca²⁺ATPase activity. The reduction in the intrinsic fluorescence intensity of actomyosin was insignificant in presence of these polyols. The inhibition of actomyosin Ca²⁺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.

Keywords:

• Sardine
• Actomyosin
• ATPase
• Polyhydric alcohols

ACKNOWLEDGEMENT

The award of Senior Research Fellowship to Sijo Mathew by Council of Scientific and Industrial Research, New Delhi during the course of this study is gratefully acknowledged.