Characterization of actin, actinin, and myosin isolated fromPhysarum

摘要

Our work on actin and myosin fromPhysarumis briefly reviewed, and the physicochemical properties of these proteins are compared with those of the corresponding proteins obtained from rabbit striated muscle. In this article both similarities and differences between these preparations are emphasized in order to characterize thePhysarumactomyosin system. Some properties ofPhysarumactinin, a regulatory protein of actin polymerization, are also reported. Finally, the assembly and disassembly of F-actin filaments in the reversible superprecipitationof Physarumactomyosin are demonstrated. The mechanism of generation of the motive force for protoplasmic streaming in plasmodium is discussed in the light of these findings.