title: Muscle beta-actinin is not chicken serum albumin.
abstract: Recently, Heizmann et al. (Proc. Natl. Acad. Sci. U.S. 78, 74-77 (1981)) reported that muscle beta-actinin and serum albumin of the chicken are indistinguishable by physicochemical and immunological criteria. It should, however, be stated that the protein the above authors called beta-actinin was entirely different from genuine muscle beta-actinin (Maruyama et. al. (1977) J. Biochem 81, 215-232). In the present study, it was experimentally shown that chicken serum albumin does not have any of the actions of beta-actinin: inhibition of reassociation of F-actin fragments, retardation of depolymerization of F-actin, instability of F-actin, acceleration of polymerization of G-actin, and formation of Mg polymer. The role of muscle beta-actinin, a heterodimer of 37,000 and 34,000 daltons, in the regulation of myofibrillar structure is summarized.
mesh_terms: D000185:Actinin / Q000494:pharmacology*; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D015636:Magnesium Chloride; D008854:Microscopy, Electron; D009124:Muscle Proteins / Q000494:pharmacology*; D009132:Muscles / Q000032:analysis; D009210:Myofibrils / Q000187:drug effects / Q000648:ultrastructure; D011108:Polymers / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D012709:Serum Albumin / Q000494:pharmacology*
chemical_list: D000199:Actins; D009124:Muscle Proteins; D011108:Polymers; D012709:Serum Albumin; D015636:Magnesium Chloride; D000185:Actinin; D011189:Potassium Chloride; D008274:Magnesium