Reversibility of scrapie-associated prion protein aggregation
Reversibility of scrapie-associated prion protein aggregation
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DOI：
10.1074/jbc.m103629200
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发表时间：
2001-07-27
影响因子：
4.8
通讯作者：
Caughey, B
中科院分区：
文献类型：
--
作者：
Callahan, NA;Xiong, LW;Caughey, B
在传染性海绵状脑病的发病过程中，羊瘙痒症朊蛋白（PrPSc）的蛋白酶抗性有序聚集体在患病动物体内积累。从机制和治疗的角度来看，它是相关的，以确定在何种程度上PrPSc的形成和聚集是可逆的。用5 M盐酸胍（GdnHCl）溶解的PrPSc展开为主要为无规卷曲构象。稀释GdnHCl后，PrP重新折叠成CD光谱测量的高α-螺旋构象，与正常细胞亚型相似。PrP（PrPC）这提供了证据表明，PrPSc可以被诱导恢复到具有强变性剂的PrPC样构象。为了检查在更生理条件下PrPSc形成和聚集的可逆性，将PrPSc聚集体洗涤并重悬于缺乏GdnHCl的缓冲液中，并随时间监测可溶性PrP的出现。在pH 6和7.5的水性缓冲液中未检测到PrP从PrPSc聚集体的解离。PrP的有效溶解度为
During the course of the transmissible spongiform encephalopathy diseases, a protease-resistant ordered aggregate of scrapie prion protein (PrPSc) accumulates in affected animals. From mechanistic and therapeutic points of view, it is relevant to determine the extent to which PrPSc formation and aggregation are reversible. PrPSc solubilized with 5 M guanidine hydrochloride (GdnHCl) was unfolded to a predominantly random coil conformation. Upon dilution of GdnHCl, PrP refolded into a conformation that was high in a-helix as measured by CD spectroscopy, similar to the normal cellular isoform. of PrP (PrPC). This provided evidence that PrPSc can be induced to revert to a PrPC-like conformation with a strong denaturant. To examine the reversibility of PrPSc formation and aggregation under more physiological conditions, PrPSc aggregates were washed and resuspended in buffers lacking GdnHCl and monitored over time for the appearance of soluble PrP. No dissociation of PrP from the PrPSc aggregates was detected in aqueous buffers at pH 6 and 7.5. The effective solubility of PrP was