Electrophoretic separation of human skeletal muscle myosin heavy chain isoforms: the importance of reducing agents.
An electrophoretic protocol previously used for the separation of rat myosin heavy chain (MHC) isoforms was slightly modified to improve the separation of human MHC isoforms in both large and minigel systems. The addition of reducing agents (beta-mercaptoethanol or dithiothreitol) to the top running buffer (TRB) radically improved separated MHC isoform resolution and the intensity of electrophoretic runs lasting longer than 5 h. In minigel systems, the MHC isoforms could be separated in as little as 5 h. The improved resolution of bands with the inclusion of reducing agents to the TRB facilitated the identification of clear boundaries for densitometric quantification of relative MHC isoform content, particularly for MHC IIa and MHC IIx. No significant effect of these reducing agents added to the TRB was observed for runs lasting only 100 min. Thus the inclusion of reducing agents in the TRB is essential for long electrophoretic runs, usually when separating large molecular mass proteins.
Kohn
Tertius Abraham
TA
Department of Physiological Sciences, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa. khm@sun.ac.za
Myburgh
Kathryn Helen
KH
D004586:Electrophoresis / Q000379:methods*; D006801:Humans; D018482:Muscle, Skeletal / Q000737:chemistry*; D018995:Myosin Heavy Chains / Q000737:chemistry* / Q000302:isolation & purification*; D020033:Protein Isoforms / Q000302:isolation & purification; D019163:Reducing Agents / Q000737:chemistry*
D020033:Protein Isoforms; D019163:Reducing Agents; D018995:Myosin Heavy Chains