Purification, molecular properties and biosynthesis of a specific protein component induced under compensatory hypertrophy in the rat skeletal muscle.

The compensatory hypertrophy in the rat skeletal muscle was induced by the method employing tenotomy and the protein components of the hypertrophied muscle were compared with those of the control muscle by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A protein component, referred to as 64-kDa protein, increased in quantity in the hypertrophied muscle. 64-kDa protein was purified to homogeneity from the extract of the rat skeletal muscle and its molecular properties were studied. Based on criteria which include molecular weight, amino acid composition and immunochemical reactivity, 64-kDa protein was indistinguishable from rat serum albumin. In vitro culture of muscle cells provided evidence showing that 64-kDa protein is synthesized in the muscle cells and rate of its synthesis is significantly greater in the hypertrophied muscle.