PURIFICATION AND PARTIAL CHARACTERIZATION OF THE NORMAL CELLULAR HOMOLOG OF THE SCRAPIE AGENT PROTEIN
PURIFICATION AND PARTIAL CHARACTERIZATION OF THE NORMAL CELLULAR HOMOLOG OF THE SCRAPIE AGENT PROTEIN
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DOI：
10.1093/infdis/158.6.1198
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发表时间：
1988-12-01
影响因子：
6.4
通讯作者：
BOLTON, DC
中科院分区：
文献类型：
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作者：
BENDHEIM, PE;POTEMPSKA, A;BOLTON, DC
羊瘙痒病病原蛋白（Sp33-37）是一种抗降解蛋白，聚集成原纤维和淀粉样斑块。这种蛋白质来源于正常细胞蛋白（Cp 33 -37）。理解Cp 33 -37转化为Sp33-37的机制可能解释羊瘙痒病病原体的复制。从正常仓鼠脑中提取Cp 33 -37，并通过免疫亲和方法纯化2700倍。从正常仓鼠脑中纯化的Cp 33 -37和从羊瘙痒病感染的仓鼠脑中纯化的Sp33-37都具有33-37千道尔顿的表观质量，并显示出糖蛋白的微异质性特征。Cp 33 -37在导致Sp33-37转化为蛋白酶抗性片段PrP 27 -30的条件下被蛋白酶K完全消化。当将Cp 33 -37脑内接种到仓鼠中时，Cp 33 -37不引起痒病。含有纯化的Sp33-37的级分具有> 1011 LD 50的瘙痒病因子/mg蛋白的平均滴度;这些滴度不被蛋白酶K降低。这些结果表明，改变敏感性蛋白水解在体外反映了一个内在的差异Sp33-37和Cp 33 -37。
The scrapie agent protein (Sp33-37) is a degradation-resistant protein that aggregates into fibrils and amyloid plaques. This protein is derived from a normal cellular protein (Cp33-37). Understanding the mechanism responsible for the conversion of Cp33-37 to Sp33-37 may explain scrapie agent replication. Cp33-37 was extracted from normal hamster brain and purified 2700-fold by an immunoaffinity method. Both Cp33-37 purified from normal hamster brain and Sp33-37 purified from scrapie-affected hamster brain had apparent masses of 33-37 kilodaltons and displayed microheterogeneity characteristic of glycoproteins. Cp33-37 was completely digested by proteinase K under conditions that resulted in conversion of Sp33-37 to the protease-resistant fragment PrP27-30. Cp33-37 did not cause scrapie when inoculated intracerebrally into hamsters. Fractions containing purified Sp33-37 had average titers of > 1011 LD50 of the scrapie agent/mg of protein; these titers were not diminished by proteinase K. These results indicate that altered sensitivity to proteolysis in vitro reflects an intrinsic difference between Sp33-37 and Cp33-37.