Structure and Mechanism of Protein Prenyltransferases

本项目涉及蛋白质戊基转移酶的结构和机制的阐明，以及 从它们的结构中获得的见解在开发治疗的新疗法中的应用 癌症，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)和香叶基香叶基转移酶-1(GGTase)，催化Over的基本共价修饰 120蛋白质通过异戊二烯类脂(异戊二烯基化)，这是定位到膜上所需的。大多数人 修饰蛋白参与细胞生长和增殖，并包括Ras GTP酶的成员 超级大家庭。抑制戊烯基转移酶已被证明是发展的一个重要目标 治疗从癌症到寄生虫和真菌感染的各种疾病。以前我们有过 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，并研究了它们与多种抗癌治疗药物的络合物的结构 线索。FTase和GGTase抑制剂(FT1和GGTIs)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，如 白色念珠菌，这可能危及免疫功能受损的艾滋病患者的生命。本研究旨在 为了加深我们对基本作用机制和底物或抑制剂的结构性理解 人类和病原体酶的特异性。我们预计这将为 选择性抑制特定靶序列戊烯基化作为新靶标的抑制剂研究进展 癌症治疗药物，以及针对特定物种的抗真菌或抗寄生虫药物。我们的方法使用的是X射线 结晶学、定点突变、动力学和抑制剂合成。其中有三个主要主题 研究内容：1)哺乳动物蛋白质的作用机理和底物特异性分析 异戊烯基转移酶。2)人类病原体蛋白戊烯基转移酶的结构-功能分析， 包括白色念珠菌、布氏锥虫、克氏锥虫和疟原虫。 3)了解特定的，ity.andjnhi.bitjon：mechaDisms.oficl[m 相关性(请参阅说明T：‘ 对有效治疗靶点的结构和机械研究是 有效应用最先进的方法开发新药。值得注意的是，蛋白质 前烯基转移酶抑制剂(FT1和GGTIs)在抗癌治疗方面也显示出相当大的前景 至于传统上难以治疗的寄生虫(如疟疾)或系统性真菌感染的治疗 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.