CHEMICAL MODELS OF PROTEIN BETA SHEET INTERACTIONS

蛋白质之间的β-折叠相互作用在许多 与疾病和正常功能相关的生物过程。 实例包括Ras和Rap通过丝氨酸/苏氨酸结合， 激酶Raf在细胞信号传导和癌基因表达中， 以及CD 4受体与HIV蛋白酶之间的相互作用。 HIV病毒蛋白gp 120。β-片层的形成也参与了 肽和蛋白质聚集形成不溶性β折叠 与各种破坏性的 神经系统疾病，包括阿尔茨海默病、克雅氏病 疾病和其他朊病毒疾病，以及亨廷顿氏病。 该提案试图通过以下方式模拟和破坏β折叠相互作用： 使用一种叫做“人造β-折叠”的化学模型系统“广阔的， 这项研究的长期目标包括发展 用于涉及蛋白质间β折叠形成的疾病的药物 (e.g.,癌症、亨廷顿氏病和阿尔茨海默氏病）和 开发制造破坏环境的化合物的一般策略 β折叠相互作用。具体目标如下：（1） 基于β-折叠的人工β-折叠结构， Met阻遏物二聚体的两半的界面将是 合成的二聚体将被合成，并且它们的结构将被 通过NMR和CD光谱研究。(2)一种人造β折叠 设计为模拟抗体的Fab部分的蛋白G结合区， 免疫球蛋白G将被合成，其与结构域的相互作用 蛋白质G的III将通过NMR光谱进行研究。(3)人工 设计用于模拟Ras之间的β-折叠界面的β折叠 蛋白质和c-Rafl激酶（Raf）以及 将合成模拟Ras和Raf的结合区域的化合物。他们的 结构和相互作用将通过CD和NMR光谱进行研究， 后两种化合物将被评估抗癌活性 由NCI使用体外60人肿瘤细胞系筛选。（四） 设计用于模拟聚谷氨酰胺β-折叠的人工β-折叠 聚集体，这是涉及亨廷顿病和其他遗传 神经退行性疾病将被合成。他们的结构将是 通过CD和NMR光谱研究，以及它们的阻断能力， 多聚谷氨酰胺β-片层聚集将使用一种免疫组织化学方法测定。 体外测定(5)设计用于阻断β-淀粉样蛋白的人工β-片层 聚合将被合成，他们的能力，以阻止其 聚集和沉积将使用体外测定来研究。

beta-Sheet interactions between proteins play a critical role in many biological processes associated with diseases and with normal function. Examples including the binding of Ras and Rap by the serine/threonine kinase Raf in cell signaling and oncogene expression, the dimerization of HIV protease, and the interaction between the CD4 receptor and the HIV viral protein gp120. beta-Sheet formation is also involved in the aggregation of peptides and proteins to form insoluble beta-sheet structures that are associated with a variety of devastating neurological disorders, including Alzheimer's disease, Creutzfeld-Jacob disease and other prion diseases, and Huntington's disease. This proposal seeks to mimic and to disrupt beta-sheet interactions by using chemical model systems called "artificial beta-sheets." The broad, long-term objectives of this research encompass both the development of drugs for diseases involving beta-sheet formation between proteins (e.g., cancer, Huntington's disease, and Alzheimer's disease) and the development for general strategies for creating compounds that disrupt beta-sheet interactions. The specific aims are as follows: (1) Artificial beta-sheet structures based upon the beta-sheet at the interface of the two halves of the met repressor dimer will be synthesized dimer will be synthesized, and their structures will be studied by NMR and CD spectroscopy. (2) An artificial beta-sheet designed to mimic the protein G binding region of the Fab portion of the immunoglobulin G will be synthesized, and its interaction with domain III of protein G will be studied by NMR spectroscopy. (3) An artificial beta sheet designed to mimic the beta-sheet interface between Ras proteins and the c-Rafl kinase (Raf) and artificial beta-sheets that mimic the binding regions of Ras and Raf will be synthesized. Their structures and interactions will be studied by CD and NMR spectroscopy, and the latter two compounds will be evaluated for anti-cancer activity by the NCI using an in vitro 60 human tumor cell line screen. (4) Artificial beta-sheets designed to mimic polyglutamine beta-sheet aggregates, which are involved in Huntington's disease and other genetic neurodegenerative diseases will be synthesized. Their structures will be studied by CD and NMR spectroscopy, and their ability to block polyglutamine beta-sheet aggregation will be determined using an in vitro assay. (5) Artificial beta-sheets designed to block beta-amyloid aggregation will be synthesized, and their abilities to block its aggregation and deposition will be studied using in vitro assays.