Enzymology of Dimethylargininase

二甲基精氨酸酶的酶学

• 批准号: 7372793
• 负责人: WALTER L FAST
• 金额: $ 25.24万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7372793
• 关键词: Active Sites; Amidines; Amyotrophic Lateral Sclerosis; Arginine; Attention; Biochemical; Biochemistry; Biological; Brain Injuries; Cancer Biology; Cancer Etiology; Catalysis; Chemicals; Chemistry; Chronic; Citrulline; Condition; Cysteine; Data; Disease; Environment; Enzymatic Biochemistry; Enzymes; Eye; Fire - disasters; Future; Health; Human; Huntington Disease; Hydrolase; Hydrolysis; Immune response; Inflammation; Ischemic Stroke; Isoenzymes; Journals; Lead; Learning; Localized; Malignant Neoplasms; Modification; Molecular; N,N-dimethylarginine; Nature; Neurons; Nitric Oxide; Nitric Oxide Synthase; Nitrogen; Oxidants; Oxidation-Reduction; Oxygen; Parkinson Disease; Pharmaceutical Preparations; Physiological; Physiology; Play; Positioning Attribute; Predisposition; Principal Investigator; Process; Production; Property; Protein Isoforms; Proteins; Public Health Applications Research; Reactive Nitrogen Species; Reactive Oxygen Species; Regulation; Research; Resources; Risk; Role; Septic Shock; Signal Transduction; Site; Stress; Stroke; System; Texas; Therapeutic; Time; Tissues; Universities; Water; Work; austin; base; blood pressure regulation; brain tissue; combinatorial; design; dimethylargininase; dimethylarginine; experience; in vivo; inhibitor/antagonist; malignant breast neoplasm; novel therapeutics; programs; response; scaffold; small molecule; tool; tumor; tumor growth

DESCRIPTION (provided by applicant): Nitric oxide (NO) is a small reactive radical that plays a significant role in cancer biology. Aberrant production of NO and other oxidants is found in various types of tumors, including breast cancer, and also at sites of chronic inflammation, which have been associated with increased risk of human cancers. In addition, NO and other oxidants have been implicated in causing neuronal damage during ischemic stroke. Humans can regulate NO production by using endogenous inhibitors of NO synthase, monomethyl- and dimethylarginine. The concentrations of these inhibitors are controlled, in turn, by two tissue specific isoforms of dimethylargininase, DDAH-1 and DDAH-2, which hydrolyze these inhibitors to remove inhibition of NO production. These two DDAH isoforms represent attractive targets for pharmacological manipulation of NO, but not much is known about how these enzymes work, how they respond to oxidative and nitrosative stress, and whether they can be inhibited selectively by small molecules. This application has three specific aims 1) to determine the catalytic mechanism of DDAH, 2) to determine whether DDAH can be regulated by biologically relevant reactive oxygen or nitrogen species, and 3) to develop inhibitors of DDAH. These studies will be completed on purified proteins with an eye toward determining functional differences between isoforms that would impact their physiological roles and that can be exploited for design of selective inhibitors. By understanding the chemistry behind DDAH catalysis and regulation, we will develop new biochemical tools with therapeutic potential, and will learn more about the role that DDAH plays in cancer biology and in the general response to oxidative and nitrosative stress. Relevance to Public Health: This application studies a key control point for the production of nitric oxide, a reactive chemical that can cause significant health problems such as promoting tumor growth in certain cancers and causing brain damage during stroke if it is not properly regulated. An understanding of the chemistry behind how this control valve works will allow us to understand how humans react to stressful physiological conditions, and will give us new biochemical tools that can be later developed into novel therapeutics.

说明(申请人提供)：一氧化氮(NO)是一种小的反应性自由基，在癌症生物学中发挥着重要作用。在包括乳腺癌在内的各种类型的肿瘤以及慢性炎症部位都发现了NO和其他氧化剂的异常产生，这与人类癌症风险的增加有关。此外，一氧化氮和其他氧化剂被认为与导致缺血性中风时的神经元损伤有关。人类可以通过使用NO合成酶、单甲基和二甲基精氨酸的内源性抑制剂来调节NO的产生。这些抑制物的浓度依次由两种组织特异性的二甲基精氨酸酶亚型DDAH-1和DDAH-2控制，这两种异构体将这些抑制物水解以消除对NO产生的抑制。这两种DDAH亚型代表了NO的药理作用靶点，但对这些酶如何工作，它们如何应对氧化和亚硝化应激，以及它们是否能被小分子选择性地抑制，我们还不是很清楚。本申请有三个具体目的：1)确定DDAH的催化机制，2)确定DDAH是否可以被生物上相关的活性氧或氮物种调节，以及3)开发DDAH的抑制剂。这些研究将对纯化的蛋白质进行，着眼于确定不同亚型之间的功能差异，这些差异将影响它们的生理作用，并可用于设计选择性抑制剂。通过了解DDAH催化和调节背后的化学原理，我们将开发具有治疗潜力的新生化工具，并将更多地了解DDAH在癌症生物学以及对氧化和亚硝化应激的一般反应中所起的作用。 与公共健康相关：这个应用程序研究一氧化氮产生的关键控制点，一氧化氮是一种活性化学物质，如果控制不当，可能会导致严重的健康问题，如促进某些癌症的肿瘤生长，并在中风期间导致脑损伤。对这个控制阀工作原理背后的化学原理的理解将使我们能够理解人类对应激生理条件的反应，并将为我们提供新的生化工具，这些工具可以在以后开发成新的疗法。