title: Polymorphism of alpha-actinin. Electrophoretic and immunological studies of rabbit skeletal muscle alpha-actinins.
abstract: Heterogeneity of alpha-actinins from rabbit skeletal muscles was studied. Polyacrylamide gel electrophoresis in the presence and absence of sodium dodecyl sulfate has made it possible to distinguish two closely related alpha-actinins from rabbit fast, white muscle. One isoprotein (designated type I alpha-actinin) appears to be preferentially located in the psoas muscle, while the other (designated type II alpha-actinin) appears to be preferentially located in the longissimus dorsi muscle. Electrophoretic analyses have further shown that the two isoproteins are present as mixtures in most rabbit white, fast-twitch muscles. A standard polyacrylamide gel--sodium dodecyl sulfate/polyacrylamide gel sequential electrophoretic procedure was developed to resolve the different alpha-actinin dimers and to determine their subunit compositions. By this technique, both type I and type II alpha-actinins appeared to be homodimers. No heterodimeric species of alpha-actinin were detected. alpha-Actinin of red, slow-twitch muscles was similar to type II alpha-actinin of fast, white muscle on one-dimensional and two dimensional gels. However, slow, red muscle alpha-actinin was significantly different from fast, white muscle alpha-actinins in terms of one-dimensional peptide mapping and immunological cross-reactivity.
mesh_terms: D000185:Actinin / Q000145:classification / Q000302:isolation & purification*; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D007120:Immunochemistry; D009124:Muscle Proteins / Q000302:isolation & purification*; D009132:Muscles / Q000032:analysis*; D011817:Rabbits
chemical_list: D009124:Muscle Proteins; D000185:Actinin