Isolation of Profilin from Embryonic Chicken Skeletal Muscle and Evaluation of Its Interaction with Different Actin Isoforms1

Abstract

An actin-binding protein of 16 kDa was isolated from embryonic chicken skeletal muscle. The protein had the same properties as profilin, exhibited a much higher affinity for cytoskeletal (β- and γ-) actins than for sarcomeric (α-) actin in the embryonic muscle, and inhibited the polymerization of β- and γ-actins more efficiently in a physiological salt solution. These results indicate that the assembly of cytoskeletal and sarcomeric actins is regulated differently by profilin in the developing skeletal muscle, and that the former may not be involved in myofibril assembly.