Isolation of a Native Connectin-Like Protein from the Plasmodium of Physarum polycephalum and its Interaction with Myosin and Actin

In 1980 we reported that there is a sodium dodecyl sulfate (SDS)-insoluble filamentous protein in Physarum, and this peculiar protein is very similar in filamentous structure and amino acid composition to connecting an elastic protein of striated muscle (Ozaki and Maruyama, 1980). Recently, Gassner and his colleagues at the University of Bonn have been able to isolate a similar protein in an SDS-soluble form and have characterized it from the viewpoint of a new cytoskeletal matrix in the Plasmodium (Gassner et al., 1985; see Chapter 15). We have also separated a similar connectin-like protein in the presence of SDS; however, all the preparations mentioned above were denatured proteins, and, therefore, its physiological function was not studied at all except for its electron microscopic structure.