MT VET COBRE PROJECT 4: ROLE OF COPPER IN PRION DISEASES

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。朊病毒疾病是哺乳动物致命的神经退行性疾病，包括克雅氏病（人类）、痒病（羊）、慢性消耗性疾病（麋鹿、鹿）和疯牛病（牛）。这些疾病的特点是在中枢神经系统中积聚错误折叠的朊病毒蛋白（PrP）。众所周知，正常形式的PrP （α -PrP）在n端结构域内的几个位点与铜（II）结合。虽然金属配位的细节和铜在这些位点的相对亲和力还不完全清楚，但一个共识的观点正在出现，即α - prp能够结合~5个单核铜（II）离子。相比之下，尽管有迹象表明铜在这种和其他淀粉样蛋白疾病中起作用，但对错误折叠的PrP中的铜环境知之甚少。PI在金属酶方面的专业知识为阐明错误折叠/感染性PrP中铜结合的细节及其对正常蛋白质转化为患病状态的影响提供了独特的视角。这一信息将有助于揭示朊病毒的传播和传染性机制。McGuirl博士的实验室正在使用生物物理技术，包括荧光和电子顺磁共振（EPR）光谱、等温滴定量热法（ITC）和电感耦合等离子体质谱法（ICP-MS），研究金属离子与重组PrP各种异构体的结合。与一些已发表的报道相反，我们没有发现在α - prp的c端半部分存在高亲和力铜（II）结合位点的证据。其他亚型的研究，包括感染性PrP，正在进行中。

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 fatal neurodegenerative diseases of mammals and include Creutzfeld-Jacob disease (humans), scrapie (sheep), chronic wasting disease (elk, deer), and mad cow disease (cattle). These illnesses are characterized by the accumulation of misfolded prion protein (PrP), in the central nervous system. It is well known that the normal form of PrP (alpha-PrP) binds copper(II) at several sites within the N-terminal domain. Although the details of metal coordination and relative affinities for copper at these sites are not completely understood, a consensus view is emerging that alpha-PrP is able to bind up ~5 mononuclear copper(II) ions. In contrast, little is known about the copper environments in misfolded PrP, despite the indications that copper plays a role in this and other amyloid diseases. The PI¿s expertise in metallo-enzymes provides a unique perspective to elucidate the details of copper binding in misfolded /infectious PrP, and its effect on the conversion of normal protein to the diseased state. This information will help unravel the mechanism of prion propagation and infectivity. Dr. McGuirl's lab is investigating metal ion binding to various isoforms of recombinant PrP using biophysical techniques, including fluorescence and electron paramagnetic resonance (EPR) spectroscopies, isothermal titration calorimetry (ITC), and inductively coupled plasma-mass spectrometry (ICP-MS). In contrast with some published reports, we see no evidence for a high affinity copper(II) binding site within the C-terminal half of alpha-PrP. Studies of the other isoforms, including infectious PrP, are ongoing.