Kurtz NIH

库尔茨国立卫生研究院

基本信息

批准号：
8130168
负责人：
DONALD M. KURTZ
金额：
$ 32.95万
依托单位：
UNIVERSITY OF TEXAS SAN ANTONIO
依托单位国家：
美国
项目类别：
财政年份：
1988
资助国家：
美国
起止时间：
1988-07-01 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8130168
关键词：
Achievement Active Sites Affinity Air Allosteric Regulation Antibiotics Bacteria Bacterial Proteins Binding Binding Proteins Cholera Dependence Detection Electrons Enzyme Inhibitor Drugs Enzyme Inhibitors Enzymes Epidemic Epitopes Escherichia coli Eukaryota Flavin Mononucleotide Flavins Freezing Genetic Goals Grant Guanosine Monophosphate Guanosine Triphosphate Guanylate Cyclase Heme Hemerythrin Homology Modeling Human Infection Investigation Iron Ligands Manuals Metals Methods Microbial Biofilms Mutate N-terminal Nitric Oxide Nitrogen Nonheme Iron Proteins Oxidation-Reduction Oxidative Stress Oxygen Proteins Reaction Research Research Support Risk Second Messenger Systems Signal Induction Signal Transduction Signaling Protein Site Solvents Structure Testing United States National Institutes of Health Vibrio cholerae Virulence Western Blotting X-Ray Crystallography antibiotic design base bis(3&apos ,5&apos )-cyclic diguanylic acid cofactor combat cryogenics design diguanylate cyclase genome sequencing high reward macrophage nitric oxide reductase nitrosative stress novel pathogen pathogenic bacteria phosphoric diester hydrolase research study response second messenger

项目摘要

DESCRIPTION (provided by applicant): Research supported by this grant in recent years has focused on what we have defined as the non-heme iron reductive paradigm for combating oxidative and nitrosative stress. This novel paradigm involves reductive scavenging of toxic reduced oxygen and nitrogen species by a group of bacterial and archaeal non-heme iron enzymes. Genetic evidence associates the functions of these enzymes in numerous bacterial and archaeal species. Based on genome sequences, these enzymes are found predominantly in air-sensitive bacteria, including those that constitute the majority of the normal human gut flora as well as human pathogens. These enzymes may protect against the oxidative and nitrosative burst of macrophages, which is the human host's initial response to infection. In the present renewal proposal, one specific aim focuses on the mechanism of reductive nitric oxide scavenging by a novel enzyme containing a combination of flavin and diiron cofactors at its active site. Single turnover experiments will be used to identify the Fe-NO species formed upon reactions of the diiron sites with nitric oxide and to determine their catalytic relevance. These themes are then logically extended to bacterial O2 sensing and signaling, induction of biofilm formation and virulence, all involving bacterial non-heme iron proteins. Enzymes from Vibrio cholerae, the bacterium causing epidemic cholerae, catalyzing formation and decay of the bacterial "second messenger", cyclic-di-guanosine monophosphate, are the focus in these latter two specific aims. These enzymes are widespread in bacteria but have not been found in higher eukaryotes. Inhibitors of these enzymes could, therefore, constitute new classes of antibiotics. Intelligent design of antibiotics requires an understanding of their catalytic and/or sensing/signaling mechanisms. These mechanisms are the overall goal of this research. PUBLIC HEALTH RELEVANCE: The enzymes proposed for study may provide protection to pathogenic bacteria against the oxidative and nitrosative burst of macrophages, which is the human host's initial response to infection. Sensing/signaling proteins from Vibrio cholerae, the bacterium causing epidemic cholera, are prominently featured in the proposed research. When the structure and function of these enzymes is understood, inhibitors of these enzymes could be designed as new classes of antibiotics.

描述（由申请人提供）：近年来该赠款支持的研究集中在我们定义为对抗氧化和亚硝化应激的非血红素还原性范式。这种新颖的范式涉及一组细菌和古细菌的非血红素铁酶还原毒性减少氧气和氮种。遗传证据将这些酶在许多细菌和古细菌物种中的功能相关联。基于基因组序列，这些酶主要在空气敏感细菌中，包括构成大多数正常人肠道菌群和人类病原体的酶。这些酶可以预防巨噬细胞的氧化和亚硝化爆发，这是人类宿主对感染的初始反应。在目前的续签建议中，一个特定的目的集中在一种新型酶在其活性位点上含有黄素和二龙辅助因子的新型酶清除的机理。单个周转实验将用于识别二铁部位与一氧化氮反应形成的Fe-NO物种，并确定它们的催化相关性。然后将这些主题从逻辑上扩展到细菌O2传感和信号传导，生物膜形成和毒力的诱导，所有这些都涉及细菌非血红素铁蛋白。来自纤维霍乱的酶，引起流行性霍乱的细菌，催化形成和细菌“第二使者”的衰变，环状二磷酸单磷酸，是后者两个特定目标的重点。这些酶在细菌中很普遍，但在较高的真核生物中尚未发现。因此，这些酶的抑制剂可能构成新的抗生素类。抗生素的智能设计需要了解其催化和/或传感/信号传导机制。这些机制是这项研究的总体目标。公共卫生相关性：提议进行研究的酶可以为致病细菌提供保护，以防止巨噬细胞的氧化和亚硝化爆发，这是人类宿主对感染的最初反应。在拟议的研究中，显着介绍了来自Vibrio cholerae的传感/信号蛋白，引起流行霍乱的细菌。当了解这些酶的结构和功能时，这些酶的抑制剂可以设计为新的抗生素。