[A redox process of ethanethiol group increases formation of beta-sheet structure and amyloid fibrils of wild type human prion protein].

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.