PROTEOLYTIC ACTIVITY AND BASIC PROTEIN LOSS IN AND AROUND MULTIPLE SCLEROSIS PLAQUES: COMBINED BIOCHEMICAL AND EIISTOCHEMICAL OBSERVATIONS

Abstract

Abstract— This combined histochemical and biochemical study has shown that acid proteinase activity (PH 3.5) is increased around histologically‐defined active plaques of multiple sclerosis (MS). Biochemical estimation showed that the enzyme is more active in most samples of ‘normal’ white matter in MS than in controls. A gradient of enzyme activity was observed: control white matter‐white matter distant from plaqueclose white matter‐edgsplaque. Both electrophoretic and histochemical techniques revealed a reduction or absence of basic (encephalitogenic) protein in the plaques. Electrophoresis showed a diminution of encephalitogenic protein outside some plaques. Phospholipids that remain on the base‐line of thin‐layer chromatoplates were shown to be predominantly phosphoinositides combined with encephalitogenic protein