title: High-resolution sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunochemical identification of the 2X and embryonic myosin heavy chains in complex mixtures of isomyosins.
abstract: In mammals myosin heavy chains (MHC) are polypeptides with a molecular mass of about 200 kDa whose isoforms can be identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunochemistry. Electrophoretic analysis is the only method for quantitating MHC profiles in single myofibers and/or cryostat sections of biopsied muscle. We present a method for SDS-PAGE of adult rat skeletal muscle which resolves MHC into four bands: 1, 2B, 2X, and 2A from the faster to the slower migrating band. Furthermore, embryonic MHC can be also resolved in a complex mixture of isomyosins, e.g. developing or regenerating muscles. The method does not involve preparation of gradient gels or electrophoresis at low temperature. Improved reproducibility is obtained by: (i) modification of the sample buffer; (ii) use of 7% polyacrylamide in the separating gel; (iii) control of pH of running buffer by recirculation or change of the buffer during the run; and (iv) a 24 h run. The procedure is compatible with Coomassie Brilliant Blue, silver and immunoblot staining. Resolution is sufficient to permit transblotting of separated MHC after SDS-PAGE. The different isoforms are easily identified with monoclonal antibodies. The technique provides an improved method to separate MHC and quantitate MHC2X and MHCemb in complex mixtures of MHC from a few cryostat sections of normal and diseased muscle.
authors.affiliation: Department of Biomedical Sciences, University of Padova, Italy.
authors.forename: K
authors.initials: K
authors.lastname: Rossini
authors.forename: C
authors.initials: C
authors.lastname: Rizzi
authors.forename: M
authors.initials: M
authors.lastname: Sandri
authors.forename: A
authors.initials: A
authors.lastname: Bruson
authors.forename: U
authors.initials: U
authors.lastname: Carraro
mesh_terms: D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D015151:Immunoblotting / Q000379:methods; D018482:Muscle, Skeletal / Q000737:chemistry; D009218:Myosins / Q000032:analysis* / Q000737:chemistry*; D051381:Rats; D012967:Sodium Dodecyl Sulfate
chemical_list: D012967:Sodium Dodecyl Sulfate; D009218:Myosins