Tsubata T, Takahashi K
Department of Biophysics and Biochemistry, Faculty of Science, The University of Tokyo.
J Biochem. 1989 Jan;105(1):23-8. doi: 10.1093/oxfordjournals.jbchem.a122611.
In order to shed some light on the role of proteinases in the process of demyelination in the central nervous system, a calcium-dependent proteinase was purified to homogeneity from bovine spinal cord, and its action on myelin basic protein purified from the same tissue was investigated. Among the three major myelin basic protein fractions, Fraction I was resistant to the action of the enzyme whereas Fractions II and III were degraded in the same manner, giving two major bands on SDS-polyacrylamide gel electrophoresis. The hydrolysis products were fractionated by high-performance liquid chromatography and characterized. The results showed that the myelin basic protein (Fractions II and III) was rather selectively cleaved at the Val93-Thr94 bond and the Arg96-Thr97 bond in mutually exclusive ways, with minor cleavages at the Ala16-Ser17 and Gly68-Ser69 bonds, suggesting the implication in vivo of calcium-dependent proteinase in the limited proteolysis of myelin basic protein.
为了阐明蛋白酶在中枢神经系统脱髓鞘过程中的作用，从牛脊髓中纯化出一种钙依赖性蛋白酶，使其达到同质，并研究了它对从同一组织中纯化出的髓鞘碱性蛋白的作用。在三种主要的髓鞘碱性蛋白组分中，组分I对该酶的作用具有抗性，而组分II和III以相同的方式被降解，在SDS-聚丙烯酰胺凝胶电泳上产生两条主要条带。通过高效液相色谱对水解产物进行分离和表征。结果表明，髓鞘碱性蛋白（组分II和III）相当选择性地在Val93-Thr94键和Arg96-Thr97键处被切割，且互斥，在Ala16-Ser17和Gly68-Ser69键处有少量切割，这表明钙依赖性蛋白酶在体内参与了髓鞘碱性蛋白的有限蛋白水解。
