State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Ying-Xin Rd 100, Beijing 100052, People's Republic of China.
Int J Biochem Cell Biol. 2011 May;43(5):768-74. doi: 10.1016/j.biocel.2011.01.022. Epub 2011 Feb 3.
Amyloid-like fibrils have been associated with the pathogenesis of human prion diseases. Prion peptide of aa 106-126 (PrP106-126) exhibits many PrP(Sc)-like biochemical features, forming amyloid-like fibrils in vitro. Here, we found that the recombinant yeast-derived molecular chaperon Hsp104 inhibited significantly the fibril assembly of the synthetic PrP106-126 peptide by dynamic ThT assays in vitro. EM assays revealed almost no fibril-like structure after incubation of the synthetic PrP106-126 peptides with Hsp104 for 12h. Circular dichroism assays identified that treatment of Hsp104 shifted the secondary structure of PrP106-126 fibrils from β-sheet to a random coil. MTT tests confirmed that interaction of PrP106-126 with Hsp104 maintained the toxicity of PrP106-126 on human neuroblastoma cell line SK-N-SH. Additionally, Hsp104 was able to disassemble the mature PrP106-126 fibrils in vitro, leading to recovering the cytotoxicity of PrP106-126 on SK-N-SH cells. Our study provides the molecular evidences that the yeast-derived Hsp104 can interfere in the fibril assembly and disassembly of human PrP106-126 segment.
淀粉样纤维与人类朊病毒病的发病机制有关。氨基酸 106-126 （PrP106-126）的朊病毒肽表现出许多 PrP（Sc）样生化特征，在体外形成淀粉样纤维。在这里，我们发现重组酵母来源的分子伴侣 Hsp104 通过体外动态 ThT 测定显著抑制合成的 PrP106-126 肽的纤维组装。EM 测定显示，在与 Hsp104 孵育 12 小时后，合成的 PrP106-126 肽几乎没有纤维样结构。圆二色性测定表明，Hsp104 处理将 PrP106-126 纤维的二级结构从β-折叠转变为无规卷曲。MTT 试验证实，PrP106-126 与 Hsp104 的相互作用保持了 PrP106-126 对人神经母细胞瘤 SK-N-SH 细胞系的毒性。此外，Hsp104 能够在体外解聚成熟的 PrP106-126 纤维，导致 PrP106-126 对 SK-N-SH 细胞的毒性恢复。我们的研究提供了分子证据，证明酵母来源的 Hsp104 可以干扰人 PrP106-126 片段的纤维组装和解体。
