EFFECT OF KCL CONCENTRATION ON THE DENATURATION OF TILAPIA MYOSIN-B BY CHANGE OF HEAT

The effects of condensation of KCl solution by freezing on the denatur ation of tilapia myosin B in 600mM KCl medium were estimated by measur ing its Ca2+-ATPase activity in the presence of different KCl concentr ations at 25 degrees C. The KCl concentration was increased by freezin g at a concentration from 600 to 3007mM at -11 degrees C near the eute ctic point; the Gibbs free energy changes (Delta G) for this solution obtained from the heat of the solidification was 0 at -2.3 degrees C a nd -163.1J/mol at -11.0 degrees C. The Ca2+-ATPase activity was decrea sed as the KCl concentration increased at a concentration from 600 to 3007mM. It was found that Delta G for the Ca2+-ATPase system was stron gly correlated to that for the solidification of KCl solution.