1990 Volume 56 Issue 2 Pages 307-314
The effect of concentrated salt solution on the freeze denaturation of carp myosin B was investigated in connection with the length of time taken to freeze to -20°C (freezing time). The apparent rate constants for the inactivation of Ca-ATPase (kf) were calculated on the basis of a -20°C-frozen-storage experiment with various combinations of freezing times and KCl concentra-tions. The slowly frozen sample resulted in a considerable decrease in Ca-, Mg- and EDTA-ATPase activities, and ATP-sensitivity of myosin B. The log kf values were correlated in a definite range with the length of time from the freezing point to the end of the eutectic plateau. A high initial KCl concentration of myosin B solution before freezing and a long freezing time resulted in a large kf value.
These findings show that the remaining activity is affected by the concentration of unforzen KCl solution and by the length of time of exposure to the concentrated solution.