CYCLOHEXANECARBOXYLIC ACID AND POLYKETIDE BIOSYNTHESIS

环己烷羧酸和聚酮化合物的生物合成

• 批准号: 7028882
• 负责人: KEVIN A REYNOLDS
• 金额: $ 31.59万
• 依托单位: PORTLAND STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7028882
• 关键词: antibiotics; bacterial genetics; biological products; biotechnology; coenzyme A; combinatorial chemistry; cyclohexane /cyclohexene carboxylate; drug design /synthesis /production; enzyme activity; genetic manipulation; microorganism metabolism; phosphatase inhibitor; polyketide synthase

DESCRIPTION (provided by applicant) Bacterial polyketide biosynthetic processes provide a wide range of structurally diverse bioactive natural products used as immunosuppressants, antibiotics, antiparasitics, growth promotants, and anticancer agents. Tremendous advances in genetic and biochemical understanding of the polyketide synthases (PKSs) and related enzymes involved in these biosynthetic processes has ushered in a new era of drug discovery in which different components of the processes can be combined or altered in order to access novel natural products. An understanding of the unique enzymes, which both provide the unusual biosynthetic precursors used in these processes, and incorporate them into a polyketide product is critical to this effort. One such example is found in ansatriemn biosynthesis where coenzyme A activated cyclohexanecarboxylic acid (CHC-CoA) is generated from a shikimate pathway intermediate, and subsequently used to generate the final antifungal polyketide product. Combining five CHC-CoA biosynthetic genes from the ansatrienin biosynthesis gene cluster of Streptomyces collznus with the avermectin biosynthetic genes in an Streptomyces a vermitilis host, has resulted in an engineered strain that produces the commercial novel antiparastic agent doramectin (an avermectin analog generated using CHC-CoA as a biosynthetic precursor). In addition to antiparasitic and antifungal agents, CHC-CoA and related compounds are important precursors used in the biosynthesis of a group of polyketide-derived protein phosphatase II inhibitors, promising antitumor agents, as well as novel functionalized antibacterial agents. The long-term objective of this application is to use the CHC-CoA biosynthetic genes and a hybrid combinatorial biosynthetic approach to generate and ultimately test the biological activity of novel members of each of these different drug classes. This objective will be accomplished through four specific aims. 1) Determination of the rate-limiting step in CHC-CoA biosynthesis and biochemical characterization of the enzymes involved in the pathway. 2) Cloning and sequencing of the biosynthetic pathway genes for formation of CHC-CoA-derived phoslactomycins, members of the important class of antitumor protein phosphatase II inhibitors. 3) Generation of new antiparasitic and antibacterial agents by using the phoslactomycin and CHC-CoA biosynthetic genes as tools to generate bacterial hosts containing hybrid polyketide synthases and CHC-CoA pathway intermediates. 4) Generation of novel protein phosphatase II inhibitors, by manipulation and combinatorial biosynthesis of the phoslactomycin biosynthetic gene cluster.

描述（由申请人提供）细菌聚酮化合物生物合成过程 提供多种结构多样的生物活性天然产品 免疫抑制剂，抗生素，抗寄生虫，生长促进剂和 抗癌剂。遗传和生化理解的巨大进步 这些涉及的聚酮化合物合酶（PKS）和相关酶 生物合成过程已经迎来了一个新的药物发现时代 可以组合或更改过程的不同组成部分，以便 访问新颖的天然产品。对独特酶的理解 两者都提供了这些过程中使用的异常生物合成前体，以及 将它们纳入聚酮化合物对这项工作至关重要。一个这样的 在Ansatriemn Biosynthesis中找到了辅酶A激活 环己烷羧酸（CHC-COA）是由寒冷的途径产生的 中级，随后用于生成最终的抗真菌聚酮化合物 产品。结合五个CHC-COA生物合成基因 链霉菌的生物合成基因簇与平脉蛋白 链霉菌中的生物合成基因是vermitilis宿主的 产生商业新型抗灾难的工程菌株 多拉氨霉素（使用CHC-COA作为生物合成产生的平均模拟素类似物 前体）。除抗寄生虫和抗真菌剂外，CHC-COA和 相关化合物是一组生物合成中使用的重要前体 聚酮化合物衍生的蛋白质磷酸酶II抑制剂，有希望的抗肿瘤 剂以及新型功能化抗菌剂。 该应用程序的长期目标是使用CHC-COA生物合成 基因和混合组合生物合成方法生成和 最终测试每个新型成员的生物学活性 不同的药物类别。这个目标将通过四个 具体目标。 1）确定CHC-COA中限速步骤 参与该酶的生物合成和生化表征 路径。 2）生物合成途径基因的克隆和测序以形成 CHC-COA衍生的phoslactomycins，重要类抗肿瘤的成员 蛋白质磷酸酶II抑制剂。 3）新的反寄生虫和 使用phoslactomycin和CHC-COA生物合成基因抗菌剂 作为生成含有杂化聚酮合成酶和的细菌宿主的工具 CHC-COA途径中间体。 4）新型蛋白质磷酸酶II的产生 抑制剂，通过操纵和组合生物合成 phoslactomycin生物合成基因簇。