Structural Biology of Oxylipin Biosynthesis

氧脂质生物合成的结构生物学

• 批准号: 7924306
• 负责人: MICHAEL G MALKOWSKI
• 金额: $ 13.51万
• 依托单位: HAUPTMAN-WOODWARD MEDICAL RESEARCH INST
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7924306
• 关键词: Acetylation; Active Sites; Adverse effects; Affect; Amino Acids; Anabolism; Animals; Anti-Inflammatory Agents; Anti-inflammatory; Arachidonic Acids; Arthritis; Aspirin; Binding; Biological; Carbon; Cardiovascular system; Caribbean region; Catalysis; Chemicals; Chemistry; Clinical; Complex; Crystallization; Cytochromes; Data; Detergents; Development; Dioxygenases; Disease; Eicosanoids; Enzymes; Exhibits; Family; Fatty Acids; Food; Generations; Goals; Health; Homeostasis; Homology Modeling; Human; Hydroxyeicosatetraenoic Acids; Immune response; Inflammatory; Invertebrates; Investigation; Leukotrienes; Life Style; Linoleic Acids; Lipids; Lipoxins; Lipoxygenase; Mediator of activation protein; Membrane; Methods; Modeling; Molecular; Molecular Conformation; Mus; Mutagenesis; Mutation; Non-Steroidal Anti-Inflammatory Agents; Oryza sativa; Oxygen; Oxygenases; Perception; Pharmacia brand of valdecoxib; Physiological Processes; Plants; Play; Polyunsaturated Fatty Acids; Process; Production; Property; Prostaglandin H2; Prostaglandin Production; Prostaglandin-Endoperoxide Synthase; Prostaglandins; Proteins; Reaction; Renal function; Reproduction; Research Personnel; Resolution; Rofecoxib; Role; Site-Directed Mutagenesis; Specificity; Structure; System; Testing; Therapeutic; base; carboxylate; celecoxib; coral; cyclooxygenase 1; cyclooxygenase 2; inhibitor/antagonist; insight; interest; lipid mediator; mutant; novel; pathogen; programs; protoporphyrin IX; stereochemistry; structural biology; vascular inflammation

DESCRIPTION (provided by applicant): OBJECTIVE: The broader goal of this proposal is to understand how different integral membrane enzymes utilize stereoselective oxygenations to generate unique oxylipins from a defined set of polyunsaturated fatty acid (PUFA) substrates. Oxylipins are bioactive lipid mediators that are biosynthesized from 18-22 carbon PUFAs through the addition of molecular oxygen via the catalytic activity of cytochrome P450s, lipoxygenases, and cyclooxygenases (COX-1 and COX-2). One of the most biologically important groups of oxylipins is the eicosanoid class, which include prostaglandins (PGs) and leukotrienes derived from arachidonic acid. These products are responsible for the modulation of basic physiologic processes and act as potent lipid mediators of the inflammatory process and other immune responses. COX-1 and COX-2 are the pharmacological target of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), including the COX-2 specific inhibitors Vioxx, Bextra, and Celebrex. SPECIFIC AIMS: Using mutagenesis, functional analyses, and x-ray crystallographic methods, we will (1) elucidate the structure of pathogen-inducible oxygenase and characterize at the molecular level the mechanism and structural determinants involved in the stereoselective oxygenation of 18 carbon PUFAs into 2R-oxylipin products; and (2) elucidate the structures of unique 15R-PG producing COX:PUFA complexes in order to understand at the molecular level how the conformation of the PUFA in the active site influences stereospecific oxygenation in the generation of these novel products. HEALTH RELEVANCE: The role that PUFAs play in health and disease is generating renewed interest, with a more focused public perception of healthy food and lifestyle and the significant impact that these compounds have in certain clinical conditions. The ability of proteins, such as COX-2, to dramatically shift their product profiles upon treatment with pharmacological inhibitors has led to further investigations into how these enzymes function. Our studies will provide for a complete mechanistic understanding of how novel lipids are derived from PUFAs upon aspirin treatment, and lend valuable insight into development of new or combined therapeutic approaches for the management of arthritis and vascular inflammation, with fewer unwanted side effects.

目的：本提案的更广泛目标是了解不同的整体膜酶如何利用立体选择性氧化从一组定义的多不饱和脂肪酸（PUFA）底物中生成独特的氧脂类。氧脂素是一种生物活性脂质介质，由18-22碳PUFAs通过细胞色素p450、脂氧合酶和环氧合酶（COX-1和COX-2）的催化活性，通过添加分子氧合成而成。在生物学上最重要的氧脂类之一是类二十烷类，包括前列腺素（pg）和从花生四烯酸中提取的白三烯。这些产物负责调节基本生理过程，并作为炎症过程和其他免疫反应的有效脂质介质。COX-1和COX-2是阿司匹林和其他非甾体抗炎药（NSAIDs）的药理学靶点，包括COX-2特异性抑制剂Vioxx、Bextra和Celebrex。具体目的：利用诱变、功能分析和x射线晶体学方法，我们将(1)阐明病原体诱导加氧酶的结构，并在分子水平上表征18个碳PUFAs立体选择性氧化成2r -氧磷脂产物的机制和结构决定因素；(2)阐明产生15R-PG的独特COX:PUFA复合物的结构，以便在分子水平上了解活性位点PUFA的构象如何影响这些新产物生成中的立体特异性氧化。健康相关性：PUFAs在健康和疾病中的作用正在引起人们新的兴趣，公众对健康食品和生活方式的认识更加集中，这些化合物在某些临床条件下具有重大影响。蛋白质，如COX-2，在药物抑制剂的治疗下显著改变其产物谱的能力导致了对这些酶如何起作用的进一步研究。我们的研究将提供一个完整的机制，了解阿司匹林治疗后PUFAs如何衍生出新的脂质，并为关节炎和血管炎症管理的新治疗方法或联合治疗方法的开发提供有价值的见解，同时减少不必要的副作用。