Abstract
In order to understand the morphological changes of carp myosin B during frozen storage, myosin B filaments were observed by an electron microscope. Myosin B in the presence of 0.1 or 0.6M KCl was stored at-5 and-20°C. ATPase activities, viscosity, and total SH groups were measured at the same time.
The granular matters and the aggregations accompanied by entangling of myosin B filaments with or without arrowhead structure were found as the main types in the deformation of the filaments during frozen storage. The proportion of transformed filaments was dependent upon the initial KCl concentration before freezing and the storage teanperature. When the myosin B was stored in 1.33M KCl solution at 10, 3, and-5°C, a lower temperature accelerated the deformation of the filaments. Morphological changes of the filaments in the electron micrographs agreed with the decrease of the viscosity rather than that of the Ca-ATPase activity. The morphological deformation and the decreasing patterns of ATPase activities and viscosity of myosin B in O.6M KCl at-5°C were very similar to those of the unfrozen myosin B in 1.33M KCl at-5°C. These findings show that myosin B is exposed to concentrated KCl solution.
