Fig. 1. Structural flexibility and functional differences of myosin isoforms from thermally acclimated carp. (A) A plot of relative Ca²⁺-ATPase activity versus incubation time (modified from Watabe et al., 1992) from which the inactivation rate constant (K_D) can be derived. (B) Arrhenius plot of the sliding velocity of F-actin on myosin (modified from Chaen et al., 1996) from which the activation energy (E_a) for sliding velocity can be derived. (C) Arrhenius plot of actin-activated Mg²⁺-ATPase activity (modified from Watabe et al., 1992) from which the E_a for actin-activated Mg²⁺-ATPase can be derived. Myosin isoforms were prepared from carp acclimated to 10°C (open circles) and 30°C (filled circles).