Activity of some proteolytic enzymes in normal and dystrophic human muscle.

1. The following proteolytic enzymes were measured in muscles of control subjects and patients with muscular dystrophies and related neuromuscular diseases: an elastase-like enzyme, carboxypeptidase A, carboxypeptidase B and pyroglutamyl peptidase. 2. Elastase-like enzyme and carboxypeptidase B did not show significant alterations in various disease conditions that were examined. 3. Carboxypeptidase A was moderately elevated in dystrophic as well as other diseased muscles. 4. Pyroglutamyl peptidase was not markedly altered in any disease condition except that is was slightly lower in dystrophic muscles.