Gamma-Actinin, a new regulatory protein from rabbit skeletal muscle. I. Purification and characterization.
A new regulatory protein which we have designated as gamma-actinin has been isolated from native thin filaments of rabbit skeletal muscle. Depolymerized native thin filaments were fractionated by salting out with ammonium sulfate, and the precipitates obtained at 40--60% ammonium sulfate saturation were further subjected to DEAE-Sephadex and Sephadex G-200 column chromatography. The purified gamma-actinin was shown to have a chain weight of 35,000 daltons and had a strong inhibitory action on the polymerization of G-actin. The results of amino acid analysis indicated a unique amino acid composition of gamma-actinin as compared with other structural proteins of muscle. Non-polar and neutral amino acid residues were abundant. One cysteine residue was contained per one molecule of gamma-actinin and played a critical role in the maintenance of the inhibitory activity. Pelleting of gamma-actinin with F-actin showed that gamma-actinin binds to F-action.
D000185:Actinin / Q000302:isolation & purification / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001718:Birefringence; D004229:Dithiothreitol / Q000494:pharmacology; D046911:Macromolecular Substances; D008274:Magnesium / Q000494:pharmacology; D008970:Molecular Weight; D009124:Muscle Proteins / Q000302:isolation & purification; D009132:Muscles / Q000378:metabolism*; D009210:Myofibrils / Q000378:metabolism; D011485:Protein Binding; D011817:Rabbits
D000199:Actins; D000596:Amino Acids; D046911:Macromolecular Substances; D009124:Muscle Proteins; D000185:Actinin; D008274:Magnesium; D004229:Dithiothreitol