Structure and Mechanism of Protein Prenyltransferases

本项目主要研究蛋白质异戊烯基转移酶的结构和作用机制， 从其结构中获得的见解在治疗新疗法的开发中的应用 以及各种寄生虫和真菌感染。两种异戊烯基转移酶，法尼基转移酶 （FTase）和1型香叶基香叶基转移酶（GGT）催化过氧化氢的必需共价修饰。 120蛋白质通过类异戊二烯脂质（异戊二烯化）定位到膜上。大部分的 修饰的蛋白质参与细胞生长和增殖，包括Ras GT酶的成员 超家族异戊二烯基转移酶的抑制已被证明是开发异戊二烯基转移酶的重要靶点。 用于治疗从癌症到寄生虫和真菌感染的疾病。以前我们有 确定了人FTase和哺乳动物GGTase的结构，从结构上定义了反应 中间体，并检查了它们与各种抗癌治疗药物的配合物的结构 线索. FT酶和GGT酶抑制剂（FTl和GGTI）显示出治疗寄生虫感染的前景 包括疟疾、恰加斯病、非洲昏睡病、利什曼原虫和真菌感染， 白色念珠菌，这可能是危及生命的免疫功能低下的艾滋病患者。本研究旨在 为了进一步了解作用的基本机制和底物或抑制剂， 对人类和病原体酶的特异性。我们预计，这将提供关键信息， 开发选择性抑制特异性靶序列异戊二烯化的抑制剂， 癌症治疗剂和物种特异性抗真菌剂或抗寄生虫剂。我们的方法是用X射线 晶体学、定点诱变、动力学和抑制剂合成。有三个主要主题， 研究内容：1）哺乳动物蛋白的作用机制和底物特异性分析 异戊二烯基转移酶。2)人类病原体异戊二烯基转移酶的结构与功能分析， 包括白色念珠菌、布氏锥虫、克氏锥虫和疟原虫。 3)Understanding specific，ity.andjnhi.bitjon：mechaDisms.. oficl[m 相关性（请参见附件：“" 对经验证的治疗靶点的结构和机制研究是研究的基本要素。 有效应用最先进的方法开发新药。值得注意的是，蛋白质 异戊烯基转移酶抑制剂（FTIs和GGTI）作为抗癌治疗剂也显示出相当大的前景 至于传统上难以治疗的寄生虫（例如疟疾）或系统性真菌感染， 请客

This project concerns the elucidation ofthe structure and mechanism of protein prenyltransferases, and the application of insights gained from their structures in the development of new therapeutics for the treatment of cancer, and various parasitic and fungal infections. The two prenyltransferases, farnesyltransferase (FTase) and geranylgeranyltransferase type-1 (GGTase), catalyze an essential covalent modification of over 120 proteins by isoprenoid lipids (prenylation) that is required for localization to membranes. Most ofthe modified proteins are involved in cell growth and proliferation and include members ofthe Ras GTPase superfamily. Inhibition of prenyltransferases has proven to be an important target for development of therapeutics for diseases ranging from cancer to parasitic and fungal infections. Previously we have determined the structures of human FTase and mammalian GGTase, structurally defined the reaction intermediates, and examined the structures of their complexes with a variety of anti-cancer therapeutic leads. FTase and GGTase inhibitors (FTls and GGTIs) show promise for treatment of parasitics infections including malaria, Chagas disease, African sleeping sickness, Leishmania and fungal infections such as Candida albicans, which can be life-threatening in immuno-compromised patients with AIDS. This study aims to further our structural understanding of the fundamental mechanism of action and substrate or inhibitor specificities for human and pathogen enzymes. We anticipate that this will provide critical information for the development of inhibitors that selectively inhibit prenylation of specific target sequences to be used as new cancer therapeutics, and species-specific antifungals or antiparasitics. Our approaches use X-ray ' crystallography, site-directed mutagenesis, kinetics, and inhibitor synthesis. There are three main themes in the research: 1) Analysis of mechanism and substrate specificities ofthe mammalian protein prenyltransferases. 2) Structure-function analysis of protein prenyltransferases from human pathogens, including Candida albicans, Trypanosoma brucei,-Trypanosoma cruzi and Plasmodium. 3) Understanding specific,ity.andjnhi.bitjon:mechaDisms..oficl[m RELEVANCE (See instructio'nsT: ' '' Structural and mechanistic investigations of validated therapeutic targets are an essential element for the effective application of state-of-the-art methods to develop new drugs. Remarkably, protein prenyltransferase inhibitors (FTls and GGTIs) show considerable promise as anticancer therapeutics as well as for treatment of parasitic (e.g. malaria) or systemic fungal infections that traditionally have been difficult to treat.