PROTEOLYTIC ENZYMES IN NORMAL AND DYSTROPHIC MOUSE MUSCLE

Abstract

Proteolytic enzymes extracted from normal and dystrophic mouse muscle were studied, and optimum conditions for their activities were established. It was found that these enzymes were active at two pH values, 7.5 and 9. In normal and dystrophic mice, the enzymatic activity increased with age. When the activities of dystrophic muscle enzymes were compared with those of normal muscle enzymes, the increase was most significant in animals 60–90 days of age. The results obtained when the enzymes extracted from normal or dystrophic muscle were incubated with substrates from normal or dystrophic muscle indicate that the defect in the muscle is due to an increase in the activities of the proteolytic enzymes rather than to a chemical change in the muscle proteins.