Enhanced protein electrophoresis technique for separating human skeletal muscle myosin heavy chain isoforms

Talmadge and Roy (J. Appl. Physiol. 1993, 75, 2337-2340) previously establi shed a sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAG E) protocol for separating all four rat skeletal muscle myosin heavy chain (MHC) isoforms (MHC I, IIa, IIx, IIb); however, when applied to human muscl e, the type II MHC isoforms (IIa, IIx) are not clearly distinguished. In th is brief paper we describe a modification of the SDS-PAGE protocol which yi elds distinct and consistent separation of all three adult human MHC isofor ms (MHC I, IIa, IIx) in a minigel system. MHC specificity of each band was confirmed by Western blot using three monoclonal IgG antibodies (mAbs) immu noreactive against MHCI (mAb MHCs, Novacastra Laboratories), MHCI+IIa (mAb BF-35), and MHCIIa+IIx (mAb SC-71). Results provide a valuable SDS-PAGE min igel technique for separating MHC isoforms in human muscle without the diff icult task of casting gradient gels.