Sterol/Hopanoid Biosynthesis: An Anti-TB Drug Target

甾醇/霍帕尼生物合成：抗结核药物靶点

• 批准号: 6348320
• 负责人: DEAN C CRICK
• 金额: $ 25.38万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-15 至 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6348320
• 关键词: Escherichia coli; Mycobacterium tuberculosis; active sites; alkyltransferase; antitubercular agents; cytochrome P450; drug resistance; enzyme inhibitors; farnesyl compound; hydrocarbons; lipid biosynthesis; microorganism metabolism; molecular cloning; pentosyltransferase; recombinant proteins; squalene; sterols; transferase

DESCRIPTION (provided by applicant): Multi-drug resistant tuberculosis is increasing in prevalence worldwide; therefore, a greater understanding of the basic biochemistry of Mycobacterium tuberculosis is of utmost importance. Analysis of the M. tuberculosis genome suggests that there may be a biosynthetic pathway analogous to eukaryotic sterol synthesis in this organism. Preliminary evidence indicates that the M. tuberculosis genome encodes enzymes with structural homology to several eukaryotic sterol synthesis enzymes including farnesyl diphosphate synthase, squalene synthase, squalene epoxidase, oxidosqualene cyclase and lanosterol 14a-demethylase. It has been shown that both the M. tuberculosis farnesyl diphosphate synthase and lanosterol 14a-demethylase are functional as well as structural homologs of the eukaryotic enzymes. More importantly, commercial anti-fungal drugs that are known inhibitors of sterol synthesis (specifically oxidosqualene cyclase and lanosterol 14a-demethylase) effectively inhibit the growth of M. tuberculosis in culture. It is hypothesized that M. tuberculosis synthesizes cyclic isoprenoid compounds, perhaps sterols or hopanoids, which are essential to the viability of the organism. Therefore, the specific aims of this proposal are to: 1) identify and characterize cyclic isoprenoid compounds in M. tuberculosis. 2) isolate, enzymatically characterize and determine the essentiality of the sterol synthesis homologs expressed by M. tuberculosis. 3) identify and characterize the active site of the oxidosqualene cyclase homolog. The identification of a sterol/hopanoid biosynthetic pathway in M. tuberculosis and characterization of relevant enzymes represents a novel approach to the identification of previously unsuspected antituberculosis drug targets.

描述（由申请人提供）： 耐多药结核病是 全球流行率不断上升；因此，对 结核分枝杆菌的基础生物化学至关重要。 对结核分枝杆菌基因组的分析表明，可能存在 生物合成途径类似于该生物体中的真核甾醇合成。 初步证据表明结核分枝杆菌基因组编码酶 与几种真核甾醇合成酶具有结构同源性 包括法尼基二磷酸合酶、角鲨烯合酶、角鲨烯环氧化酶、 氧化角鲨烯环化酶和羊毛甾醇14a-去甲基酶。事实证明 结核分枝杆菌法尼基二磷酸合酶和羊毛甾醇 14a-去甲基酶与真核生物具有功能和结构同源性 酶。更重要的是，已知的商业抗真菌药物 甾醇合成抑制剂（特别是氧化角鲨烯环化酶和 羊毛甾醇14a-去甲基酶）有效抑制结核分枝杆菌的生长 在文化中。据推测，结核分枝杆菌合成环状 类异戊二烯化合物，可能是甾醇或藿类化合物，它们对于 有机体的生存能力。因此，本提案的具体目标是 目的：1) 鉴定并表征 M 中的环状类异戊二烯化合物。 结核。 2) 分离、酶学表征并确定 结核分枝杆菌表达的甾醇合成同系物的重要性。 3） 鉴定并表征氧化角鲨烯环化酶同系物的活性位点。 结核分枝杆菌中甾醇/藿香类生物合成途径的鉴定 相关酶的表征代表了一种新的方法 鉴定以前未曾怀疑的抗结核药物靶点。