Effect of Tropomyosin on the Interaction between F-actin and the 6S Component of α-Actinin

Interaction among F-actin, 6S component of α-actinin and tropomyosin was investigated by turbidity, viscosity and flow birefringence measurements. 6S component of α-actinin caused gelation of F-actin, eventually leading to precipitation. Tropomyosin, when added before, inhibited the precipitation of F-actin by 6S component. These results were presented in details, and possible physiological importance of the interactions among the three muscle structural proteins was discussed in relation to the structure of myofibrils.