FIBER DIFFRACTION FROM AMYLOIDS INCLUDING PRIONS

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 淀粉样纤维是当正常的可溶性蛋白质改变构象而形成不溶于水的细丝时形成的，这可能会导致严重的损害甚至死亡。淀粉样变性包括阿尔茨海默病、II型糖尿病、遗传性淀粉样变性和多种普恩疾病，包括克雅氏病、疯牛病和瘙痒病。哺乳动物的Prion是PrP蛋白折叠成异常结构时形成的具有感染性的蛋白质聚集体。淀粉样蛋白也是由酵母蛋白形成的。 淀粉样蛋白具有交叉贝塔结构，但结构细节尚不清楚。淀粉样纤维不能用结晶学或核磁共振来表征。纤维衍射法是一种确定丝状结构细节的有效方法，为阐明Pron和其他淀粉样蛋白的结构提供了最大的希望。需要结构研究来回答基本的蛋白质折叠问题，以了解淀粉样蛋白的形成和合理的药物设计。 我们使用非常少量的材料在受控条件下制造干燥的纤维。重组普恩病毒为获得材料开辟了新的可能性，但我们已经证明，合成的普恩病毒和脑来源的普恩蛋白之间存在结构差异，这些差异尚未得到充分的表征。改进的Pron可获得性、改进的样品制备方法和高质量的强同步辐射共同提供了获得改进的淀粉样衍射数据的前所未有的机会。 数据将从哺乳动物羊痒病来源的Pron和重组羊痒病来源的Prion合成的淀粉样多肽中获得。将收集广角和低角度数据。我们已经证明，子午线数据可以确定交叉β结构的性质，赤道数据可以用来描述原丝结构。完整的衍射数据将用于评估和改进淀粉样蛋白结构的竞争模型。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Amyloid fibers are formed when normally soluble proteins change conformation to form insoluble filaments that can cause severe damage and even death. Amyloidoses include Alzheimers disease type II diabetes hereditary amyloidoses and a variety of prion diseases including Creutzfeldt-Jakob disease BSE (mad cow disease) and scrapie. Mammalian prions are infectious protein aggregates formed by the protein PrP when it folds into aberrant structures. Amyloids are also formed by yeast prion proteins. Amyloid proteins share a cross-beta structure but the structural details are not known. Amyloid fibers cannot be characterized by crystallography or NMR. Fiber diffraction is an effective method for determining the structural details of filamentous assemblies and offers the best hope for elucidating the structures of prions and other amyloids. Structural studies are needed to answer fundamental protein folding questions to understand amyloid formation and for rational drug design. We use very small quantities of material to make dried fibers under controlled conditions. Recombinant prions open up new possibilities of obtaining material but we have shown that there are structural differences between synthetic and brain-derived prions which have yet to be characterized fully. Improved prion availability improved methods of specimen preparation and intense high quality synchrotron radiation together offer an unprecedented opportunity to obtain improved amyloid diffraction data. Data will be obtained from synthetic amyloid peptides from mammalian scrapie-derived prions and from recombinant scrapie-derived prions. Wide-angle and low-angle data will be collected. We have shown that meridional data can determine the nature of the cross-beta structure and equatorial data can be used to describe protofilament structure. The complete diffraction data will be used to evaluate and improve competing models for amyloid structure.