Abstract
Carp myofibrils suspended in 5 and 50mM phosphate buffer (pH 6.8) were stored at -4, -11, and -26°C for 167 days, and the changes in volume of myofibrillar protein components in salt-soluble and salt-insoluble fractions were followed by polyacrylamide gel electrophoresis. The extents of the decrease of actin and myosin heavy chain components in the salt-soluble fraction and the increase of those in the salt-insoluble fraction were greater, and the insolubilization of those components was accelerated with an increase in storage temperature at both buffer concentrations. Under all storage conditions, there was a transient steady stage during which the changes of actin and myosin heavy chain components were very small in each fraction. The steady stages in 5 and 50mM phosphate buffers occurred at storage periods 10-89 (or 10-40) and 40-89, respectively, and especially those of the actin component in the salt-insoluble fraction were evident. The beginning of the steady stage in 5mM phosphate buffer was earlier than that in 50mM. It seems that the myofibrils were insolubilized as the actin-myosin complex in the storage range of 0-23 days at -4°C in 5mM phosphate buffer and in the range of 0-89 days under all other storage conditions.
