Influences of actin, pH, MgCl2, and urea on actin-activated Mg-ATPase activity of carp and tilapia myosins, along with the reversibility of those influences, were investigated.
The actin activated Mg-ATPase activity of both myosins was affected by the concentrations of actin, MgCl2, and urea or pH. The changes caused were found to be reversible.
The turbidity of myosin suspension was also affected by pH and the concentration of MgCl2.
The present results, along with some other data, suggested that such changes in actin-activated Mg-ATPase activity of fish myosin depend on different states of the filaments formed, and are species-specific.