Biochemistry Of Scrapie Pathogenesis

传染性海绵状脑病（TSE或朊病毒病）是致命的神经退行性疾病，如羊瘙痒病、克雅氏病（CJD）、疯牛病和慢性消耗性疾病（CWD）。我们的项目旨在了解和阻断PrP-res的积累，PrP-res是朊病毒蛋白（PrP）的异常形式，似乎是TSE传播和发病机制的基础。使用细胞培养和无细胞系统，我们已经1）鉴定了新的基于嘧啶的分子和四吡咯作为PrP-res形成的抑制剂，2）鉴定了作为TSE菌株的函数而不同折叠的PrP-res的区域，3）确定了PrP-res中的二硫键是分子内的而不是分子间的，4）开发了新的更生理性的基于膜囊泡的PrP转化反应，5）表征了PrP-res和正常PrP在相同膜中的共定位对于有效转化反应的重要性，6）进一步表征了PrP-res聚集的可逆性，6）表征了硫酸乙酰肝素和其他硫酸化聚糖对PrP-res形成的刺激，7）比较了各种去污剂诱导正常PrP中的构象变化和原纤维形成的能力，这些变化和原纤维形成使人联想到PrP-res形成。

Transmissible spongiform encephalopathies (TSEs or prion disease) are fatal neurodegenerative diseases such as scrapie, Creutzfeldt-Jakob disease (CJD), BSE and chronic wasting disease (CWD). Our project is aimed at understanding and blocking the accumulation of PrP-res, the abnormal form of prion protein (PrP) that appears to underlie TSE transmission and pathogenesis. Using cell culture and cell-free systems we have 1) identified new pyrimidine-based molecules and tetrapyrroles as inhibitors of PrP-res formation, 2) identified regions of PrP-res that are differently folded as a function of TSE strain, 3) determined that the disulfide bonds in PrP-res are intramolecular rather than intermolecular, 4) developed new more physiological membrane vesicle-based PrP conversion reactions, 5)characterized the importance of colocalization of PrP-res and normal PrP in the same membranes for efficient conversion reactions, 6) further characterized the reversibility of PrP-res aggregation, 6)characterized the stimulation of PrP-res formation by heparan sulfate and other sulfated glycans, 7) compared the abilities of various detergents to induce conformational changes and fibril formation in normal PrP that are reminiscent of PrP-res formation.