Abstract
G-actin was extracted from the acetone-dried myofibril-powder of walleye pollack, rainbow trout, carp and rabbit, and was purified by collecting the pellet at 40% saturated ammonium sulfate. Their thermal denaturation upon heating in the presence of ATP was compared by monitoring the actin-activated subfragment-1 Mg-ATPase, and the chymotryptic digestability. It was demonstrated that there is practically no difference in the stability among species; G-actin denaturation took place above 50°C for all species. Thermal stability of walleye pollack actin in myofibril was studiedby measuring the amount of G-actin extracted from the acetone dried powder of the heated myofibril. Decrease was detected above 50°C, which was rather similar to that for causing G-actin enaturation.
