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人类朊病毒病中约10%~15%具有家族遗传特性,其中插入或缺失突变多发生于PrP蛋白N末端的八肽重复区域。运用PCR成功地构建并表达了含不同八肽重复数目的PrP蛋白,并观察八肽重复数目的增加对PrP与Cu2+等二价离子以及tau蛋白的相互作用的影响。实验结果显示:各种纯化后的PrP蛋白对常规浓度PK消化是敏感的,而与Cu2+共同孵育可使PrP蛋白的PK抗性增强;八肽重复序列的数目及Cu2+的浓度决定了PK抗性的出现和强弱。另外,Mn2+可诱导产生与Cu2+相似的结果,但其诱导效应似乎低于Cu2+,而Zn2+对PrP蛋白的PK抗性无影响。GST-tau包被的ELISA检测证实,重组的PrP呈现出明显的tau蛋白结合能力,并且与八肽重复序列的数量相关,重复序列数量越多,结合能力越强。这些结果提示,Cu2+诱导产生的PrP蛋白PK抗性是通过八肽重复序列区域产生的,并且直接与重复序列的数量相关。另外,PrP蛋白八肽重复序列的存在和数量直接影响PrP与tau蛋白的结合效应。除了八肽区域外,PrP蛋白其它区域似乎也具有一定的tau蛋白结合能力。
About 10% to 15% of human prion diseases have familial hereditary properties, in which insertions or deletions occur more frequently in the octapeptide repeat region at the N-terminus of the PrP protein. We successfully constructed and expressed PrP protein with different octapeptide repeat number by PCR and observed the effect of the increase of octapeptide repeat number on the interaction between bivalent ions such as PrP and Cu2 + and tau protein. The results showed that all the purified PrP proteins were sensitive to conventional PK digestion. However, incubation with Cu2 + could enhance the PK resistance of PrP protein. The number of octapeptide repeats and the concentration of Cu2 + determined PK resistance The emergence and strength. In addition, Mn2 + induced a similar result to that of Cu2 +, but its induction effect appeared to be lower than that of Cu2 +, whereas Zn2 + had no effect on PK resistance of PrP protein. GST-tau coating ELISA test confirmed that the recombinant PrP showed a significant tau protein binding capacity, and octapeptide repeat sequence number, repeat sequence number, the stronger the binding capacity. These results suggest that PK resistance induced by Cu2 + -induced PrP protein is produced by octapeptide repeat regions and directly correlates with the number of repeats. In addition, the presence and amount of PrP protein octapeptide repeats directly affect the binding effect of PrP to tau protein. In addition to the octapeptide region, other regions of the PrP protein also appear to have some tau binding ability.