A Set of Actin-Filament Associated Proteins Characterized by Quantitative Two-Dimensional Gel Electrophoresis

Abstract

Our laboratories have been using two-dimensional gel electrophoresis and monoclonal antibody techniques for the study of contractile and structural proteins. The resolving power of the two-dimensional gels, combined with computer methods for quantitation and pattern matching, have been used in previous studies to analyze the proteins of cultured L6 muscle cells as they differentiate from myoblasts to myotubes (453,497,498). Highly specific monoclonal antibodies have made possible the identification and biochemical characterization of major and minor structural proteins. Matsumura et al (1983) have used the monoclonal antibodies to tropomyosins to identify 5 isoforms that are present in several rat cell lines (499). These results confirm and extend the earlier identification of tropomyosin isoforms in L6 myoblasts (453). Matsumura et al (1983) have further shown that actin-filament assemblies can be purified from non-muscle and muscle cells as ordered bundles cross-linked in a highly regular fashion by monoclonal antibodies to tropomyosin. (500).