[Comparative study of the properties of a proteolytic enzyme isolated from the myelin of animals and from the biological fluids of disseminated sclerosis patients].

A proteolytic enzyme with the activity of 8-26 U/mg protein was isolated from purified animal myelin preparation obtained by an original technique. The optimal pH of the enzyme was found to be 9.6-9.8. Its substrate specificity was studied. An enzyme with similar characteristics and identical electrophoretic mobility was isolated from the blood serum of patients with disseminated sclerosis and then purified. The major part of the enzyme activity in the blood and myelin was bound and was manifested only after special treatment. It is suggested that a similar proteolytic enzyme is present in human myelin, whose activation in demyelinating diseases may result in myelin destruction.