3-Ketoacyl ACP Synthase III: A Novel Antibiotic Target

3-酮脂酰 ACP 合酶 III：新型抗生素靶点

• 批准号: 7026511
• 负责人: KEVIN A REYNOLDS
• 金额: $ 28.22万
• 依托单位: PORTLAND STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7026511
• 关键词: X ray crystallography; acetyl coA; active sites; acyl carrier protein; antibacterial agents; antibiotics; antiinfective agents; antimalarial agents; catalyst; chemical binding; drug design /synthesis /production; drug interactions; drug screening /evaluation; enzyme inhibitors; enzyme structure; enzyme substrate; fatty acid biosynthesis; fatty acid synthase; fluorimetry; nuclear magnetic resonance spectroscopy; polymerase chain reaction; site directed mutagenesis; stop flow technique

DESCRIPTION (provided by applicant): Fatty acid biosynthesis by a type II dissociated fatty acid synthase (FAS) is a fundamental and indispensable metabolic pathway in many organisms, including bacteria and parasites. The distinctions between this and the multifunctional type I FAS of higher organisms offer a selective target for the design of novel antibacterial and antiparasitic agents, needed to combat the resurgence of antibiotic-resistant bacteria and multidrug-resistant forms of the malaria-causing plasmodial parasites. In all type II FAS systems, the initial condensation step is carried out by 3-ketoacyl acyl carrier protein (ACP) synthase III (KASIII, FabH), which catalyzes the condensation of an acyl CoA substrate with malonyl ACP to generate a 3-ketoacyl ACP product. FabH also appears to play a key role in regulation of fatty acid biosynthesis and is not targeted by any current drugs, making it a particularly attractive new target for drug design. The long-term objective of our work is to understand the structural and mechanistic bases of FabH that define its physiological roles and to use this information to generate novel potent and selective inhibitors. This grant will extend our study of FabH enzymes from organisms such as Escherichia coil and Staphylococcus aureus, which initiate de novo fatty acid biosynthesis from different short chain acyl CoA substrates, and Mycobacterium tuberculosis, which uses FabH to initiate mycolate biosynthesis from long chain acyl CoA substrates. Mutational analyses and crystallography will be used to investigate the differing substrate and inhibitor specificities of these enzymes. In conjunction with ongoing crystallographic, molecular modeling and kinetic analyses, the mode of binding of 1,2-dithiole-3-one and related compounds which are potent novel active site FabH inhibitors, and a second series of inhibitors that appear to bind in the FabH phosphopantetheine binding channel, will be investigated. The information gathered from these studies will be used to design, synthesize and ultimately test inhibitors, which maximize interactions with both active site residues and those in either the acyl-binding pocket or phosphopantetheine-binding channel. Such compounds should have enhanced activity and selectivity against FabH and be powerful new lead compounds for development of novel antibacterial and antiparastitic/antimalarial drugs.

描述（由申请人提供）：II型解离脂肪酸合酶（FAS）进行的脂肪酸生物合成是许多生物体（包括细菌和寄生虫）中基本且不可或缺的代谢途径。它与高等生物的多功能 I 型 FAS 之间的区别为新型抗菌和抗寄生虫药物的设计提供了选择性目标，这些药物需要对抗抗生素耐药细菌和引起疟疾的疟原虫的多重耐药形式的复活。在所有 II 型 FAS 系统中，初始缩合步骤均由 3-酮脂酰酰基载体蛋白 (ACP) 合酶 III (KASIII、FabH) 进行，该酶催化酰基 CoA 底物与丙二酰 ACP 缩合，生成 3-酮脂酰基铝塑板产品。 FabH 似乎在脂肪酸生物合成的调节中也发挥着关键作用，并且不是任何现有药物的目标，这使其成为药物设计特别有吸引力的新靶点。 我们工作的长期目标是了解 FabH 的结构和机制基础，从而定义其生理作用，并利用这些信息来生成新型有效的选择性抑制剂。这笔资助将扩展我们对来自大肠杆菌和金黄色葡萄球菌等生物体的 FabH 酶的研究，这些酶从不同的短链酰基辅酶 A 底物启动脂肪酸生物合成，而结核分枝杆菌则使用 FabH 启动长链酰基辅酶 A 进行分枝菌酯生物合成。基材。突变分析和晶体学将用于研究这些酶的不同底物和抑制剂特异性。结合正在进行的晶体学、分子建模和动力学分析，1,2-二硫醇-3-酮和相关化合物的结合模式（它们是有效的新型活性位点 FabH 抑制剂）以及似乎结合在将研究 FabH 磷酸泛硫氨酸结合通道。从这些研究中收集的信息将用于设计、合成和最终测试抑制剂，这些抑制剂最大限度地提高与活性位点残基以及酰基结合口袋或磷酸泛硫氨酸结合通道中的残基的相互作用。 此类化合物应具有增强的针对 FabH 的活性和选择性，并且是用于开发新型抗菌和抗寄生虫/抗疟药物的强大的新先导化合物。