Degradation of myelin proteins by brain endogenous neutral protease.
A proteolytic enzyme isolated from calf brain cytosol, degraded purified myelin basic protein in the presence of Ca2+ at pH 7.0 (Singh, I. and Singh, A.K., Trans. Amer. Soc. Neurochem., 13 (1982) 119). This proteolytic enzyme also degrades basic proteins when incubated with intact myelin in the presence of Ca2+ at a neutral pH. Three hour treatment of purified myelin with this protease resulted in degradation of large basic protein and small basic protein by 73 and 89%, respectively. This proteolytic activity was inhibited by EDTA, leupeptin and low pH (pH 4.0), but was not affected by phenylmethylsulfonylfluoride, p-nitrophenylguanidinobenzoate and pepstatin A. Purified myelin preparations also contain small amounts of Ca2+-activated proteolytic activity. The fact that this is a neutral protease, endogenous to the brain, suggests that it may play a role in the degradation of myelin under physiological and pathological conditions.
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D002384:Catalysis; D002417:Cattle; D004789:Enzyme Activation; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D004676:Myelin Basic Protein / Q000378:metabolism*; D009186:Myelin Sheath / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism*
D004676:Myelin Basic Protein; D010447:Peptide Hydrolases; D002118:Calcium