Abstract
Upon heating of carp myosin, actin-activated Mg-ATPase activity decreased much faster than its Ca-ATPase activity. Sepharose CL 4 B gel filtration revealed that myosin formed oligomer, which retained its Ca-ATPase activity; oligomer at void volume (Vo) on Sepharose CL 4 B exhibited ATPase activity. However, the Mg-ATPase/Ca-ATPase activity ratio for the Vo fraction was very low. Myosin filament formed by the oligomeric myosin at Vo was irregular. It was concluded that the low actin activated Mg-ATPase activity is responsible for the filament formed by oligomeric myosin. Oligomers were easily salted-out at 40% saturated ammonium sulfate, leaving monomers in the soluble fraction.
