SPECIFICITY IN TERPENE AND STEROL BIOSYNTHESIS

萜烯和甾醇生物合成的特异性

• 批准号: 2629005
• 负责人: ROBERT M. COATES
• 金额: $ 27.27万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-03-01 至 2002-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2629005
• 关键词: X ray crystallography; active sites; chemical models; chemical synthesis; enzyme complex; enzyme inhibitors; enzyme mechanism; enzyme substrate analog; isoprenoid; lipid biosynthesis; squalene; stable isotope; stereochemistry; steroid biosynthesis; sterols; terpenes

The major goal of this research program is to develop a fundamental understanding of the specificity, catalytic and control mechanisms, active site structures, and biological functions of key enzymes involved in terpene and sterol biosynthesis. Syntheses and applications of isotope-labelled substrates and intermediates, transition state-analog inhibitors, and related compounds are proposed to elucidate mechanistic aspects of the reactions, structures and conformations of intermediates, and 3-dimensional interactions in enzyme-substrate (or intermediate) analog complexes. Enzymatic experiments and X-ray diffraction analyses of the enzyme complexes will be carried out by collaborations with several biochemists and protein crystallographers. The stereochemistry and mechanistic characteristics of alkylations, cyclizations, and rearrangements catalyzed by squalene, taxadiene, abietadiene, epi-aristolochene, and vetispiradiene synthases as well as protein prenyl transferases will be elucidated to identify factors responsible for product specificity. Experiments with substrate analogs will probe active site tolerances, enable identification of enzyme-bound intermediates, and lead to novel isoprenoid products. Transition-state inhibitors as well as heavy-atom and other analogs of substrates and intermediates are proposed for use as active site and reaction pathway markers in X-ray crystallographic studies of isoprenoid synthases, or as photo-activatable agents for investigation of prenylated protein complexes. Fundamental knowledge concerning the substrate specificity, mechanisms, and catalytic functionality of enzymes such as epi-aristolochene, vetispiradiene, and taxadiene synthases may lead to more efficient production of the phytoalexins capsidiol and solavetivone for agricultural uses, or the chemotherapeutic agent taxol for cancer treatment, or lead to discovery of more active derivatives. High affinity inhibitors of squalene synthase have the potential to block cholesterol biosynthesis without deleterious side effects on the formation of other essential isoprenoid metabolites. Specific prenyl transferase inhibitors would have significant biochemical applications in the study of regulatory and signal-transducing proteins, as well as potential in cancer chemotherapy.

该研究计划的主要目标是开发基本 了解特异性，催化和控制机制， 涉及关键酶的活性位点结构和生物学功能 在萜烯和固醇生物合成中。 合成和应用 同位素标记的底物和中间体，过渡状态分析 提出了抑制剂和相关化合物以阐明机械 中间体的反应，结构和构象的各个方面， 和酶 - 基底（或中间）中的3维相互作用 模拟复合物。 酶促实验和X射线衍射分析 酶综合体将通过与 几位生物化学家和蛋白质晶体学家。 烷基化的立体化学和机械特征， 环绕和重新排列，由Spolene，TaxaDiene催化， Abietadiene，Epi-Aristolochene和Vetispiradiene合酶以及 将阐明蛋白质前转移酶以识别因素 负责产品特异性。 底物类似物的实验 将探测主动位点的公差，可以鉴定酶结合 中间体，并导致新型类异戊二烯产物。过渡状态 抑制剂以及底物和其他类似物的抑制剂和其他类似物 提出中间体用作活性位点和反应途径 类异型合酶的X射线晶体学研究中的标志物，或 作为用于研究原蛋白的光活化剂 复合物。 有关底物特异性，机制， 酶的催化功能，例如Epi-Aristolochene， vetispiradiene和taxadiene合酶可能会提高效率更高 生产植物甲二二醇和溶剂二醇的生产 农业用途或癌症的化学治疗剂紫杉醇 处理或导致发现更活跃的衍生物。 高的 小矛烯合酶的亲和力抑制剂有可能阻止 胆固醇生物合成没有有害的副作用 其他必要的异丙代代谢产物的形成。 特异性前肾 转移酶抑制剂将具有重要的生化应用 在调节和信号转移蛋白的研究中以及 癌症化疗的潜力。