Sun Han, Shi Qi, Wang Shao-Bin, Guo Fei, Xie Wu-Ling, Chen Cao, Liu Cun-Qi, Dong Xiao-Ping
State Key laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Diseases Control and Prevention, Beijing 102206, China.
Bing Du Xue Bao. 2012 Jun;28(4):409-13.
In order to explore the potential influences of the disulfide bridge on the physical and chemical properties of PrP protein, the expressed recombinant human wild-type PrP protein was purified for using in an established redox process for the reduction and oxidation of the ethanethiol group within PrP. Sedimentation tests illustrated that redox process remarkably promoted the aggregation of recombinant PrP. Thioflavin T binding assay revealed an enhanced fibrillization of the recombinant human PrP after redox process. Far-UV circular dichroism demonstrated that the PrP treated with redox process showed a significant p-sheet rich structure. Furthermore, PrP-specific Western blot identified that the recombinant PrP after redox possessed stronger proteinase K-resistance. Those data indicates that the formation of the disulfide bridge induces the alteration of the secondary structure and enhances the progresses of aggregation and fibrillization of PrP protein.
为了探究二硫键对朊蛋白（PrP）物理和化学性质的潜在影响，对表达的重组人野生型PrP蛋白进行纯化，用于已建立的氧化还原过程，以还原和氧化PrP中的乙硫醇基团。沉降试验表明，氧化还原过程显著促进了重组PrP的聚集。硫黄素T结合试验显示，氧化还原过程后重组人PrP的纤维化增强。远紫外圆二色性表明，经过氧化还原处理的PrP呈现出富含β-折叠的结构。此外，PrP特异性免疫印迹鉴定出氧化还原后的重组PrP具有更强的蛋白酶K抗性。这些数据表明，二硫键的形成诱导了二级结构的改变，并增强了PrP蛋白的聚集和纤维化进程。
