Myosin was prepared from the striated adductor muscle of giant ezo scallop, patinopecten yessoensis, by the original method of BÁRÁNY et al.
This myosin showed the typical biological activity of myosin as already known tor rabbit myosin; that is, high ATP hydrolyzing activity and actin-binding ability.
The actin-bingding ability of this myosin was examined by measuring the increase in ATP-sensitivity, superprecipitation, the enhancement of Mg²⁺-ATPase and the stabilization of Ca²⁺-ATPase for thermal denaturation.
The first order rate constants for the thermal denaturation of Ca²⁺-ATPase (K_D) were determined to be 22×10^-4•sec^-1 at 30°C, and 61-128×10^-4•sec^-1 at 35°C, while those of rabbit myosin were 1.5×10^-4•sec^-1 at 30°C, and 3.7×10^-4•sec^-1 at 35°C.
SDS-gel electrophoresis indicated that a small amount of paramyosin and a trace of actin remained in this myosin preparation.