Studies on the proteins of fish skeletal muscle. 7. Denaturation and aggregation of cod myosin

Abstract

The aggregation of cod myosin monomer at concentrations of 0.2-1.5% was studied by following changes in weight-average molecular weight, sedimentation, diffusion, viscosity and optical rotation. The kinetics of the disappearance of monomer were analyzed and can be plausibly 4305[1960] BIOCHEMISTRY 49678-49693 accounted for by assuming that the reaction involves 2 steps a denatura-tion stage followed by a relatively rapid stepwise side-to-side aggregation. Additional evidence for a denaturation stage has come from a study of the reaction at different temperatures, conditions of pH and ionic strength, from the effects of added substances and from an examination of the concurrent enzymic inactivation. Aggregation, which under extreme conditions is often accompanied by a dissociation of the molecule, cannot be explained on the basis of sulfhydryl-disulfide interactions.