STRUCTURAL CHARACTERIZATION OF PRION PROTEINS

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 朊病毒病是由朊病毒引起的一种独特的致命性神经退行性疾病。朊病毒的唯一组成部分是一种称为朊病毒蛋白（PrP）的正常细胞蛋白质的异常形式。正常形式（PrPC）通过一个尚未确定的翻译后过程转化为致病形式（PrPSc）。质谱法对于从生物组织、重组来源和肽合成中分离的朊病毒蛋白的小规模样品的详细分析至关重要。一个目的是增加检测亚化学计量修饰的灵敏度，因为已知感染性的一个ID 50含有数万个PrP分子，并非所有这些分子本身都必然是致病性的。也有必要鉴定可能存在于感染性朊病毒中的可能的辅助分子。还需要比较来自不同朊病毒株的PrPSc，以确定菌株行为是否可能源于共价差异，例如N-连接寡糖，这可能导致细胞特异性凝集素靶向有限范围的细胞类型，从而导致PrPSc的区域分布。到目前为止获得的结果表明，在PrPSc的形成所涉及的PrPC的修改可能是构象，而不是化学。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Prion diseases are unique fatal neurodegenerative diseases caused by novel pathogens termed prions. The only component of prions is an abnormal form of a normal cellular protein termed the prion protein (PrP). The normal form (PrPC) is converted to the pathogenic form (PrPSc) by an as yet unidentified posttranslational process. Mass spectrometry is essential for the detailed analysis of small-scale samples of the prion protein isolated from biological tissues, from recombinant sources and from peptide synthesis. One objective is increase the sensitivity for detection of sub-stoichiometric modifications as it is known that one ID50 of infectivity contains tens of thousands of PrP molecules, not all of which are necessarily pathogenic in their own right. It is also necessary to identify possible accessory molecules that might be present in infectious prions. Comparisons are also required between PrPSc from different prion strains to establish whether strain behavior could arise from covalent differences, e.g. in the N-linked oligosaccharides, which might cause cell specific lectins to target a limited range of cell types, resulting in regional distribution of PrPSc. Results obtained so far suggest that the modification of PrPC involved in the formation of PrPSc is likely conformational rather than chemical.