Structural insights into redox homeostasis

氧化还原稳态的结构见解

• 批准号: 7075266
• 负责人: JOSEPH J BARYCKI
• 金额: $ 20.23万
• 依托单位: UNIVERSITY OF NEBRASKA LINCOLN
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7075266
• 关键词: NAD(P)H oxidoreductase; carbon nitrogen ligase; cellular respiration; electron transport; enzyme mechanism; enzyme structure; glutathione; mitochondria; protein glutamine gamma glutamyltransferase; thioredoxin

DESCRIPTION (provided by applicant): Efficient intracellular electron transfer is essential to organisms that use oxygen. An exquisite balance between oxidized and reduced enzymes and cofactors, termed redox homeostasis, must be carefully regulated to maintain cellular function. Loss of redox balance underlies molecular changes associated with aging and age related diseases. Consequences of acute or chronic disruption in redox homeostasis include neurodegenerative diseases, cancer, diabetes mellitus, atherosclerosis, and rheumatoid arthritis. To investigate the specific molecular and chemical events that govern redox balance, structural and biochemical studies of enzymes that preserve cellular redox potential will be examined. In particular, the proposed research will consider the enzymatic pathways responsible for the maintenance of reduced thioredoxin and glutathione pools by addressing the following specific aims: (i) Characterize the electron transfer cascade catalyzed by mitochondrial thioredoxin reductase at the molecular level. The goal of this aim is to use structural analysis and biochemical characterizations to examine the mechanistic details of the thioredoxin system as it pertains to mitochondrial redox homeostasis. We will determine the crystal structures of mitochondrial thioredoxin and glutaredoxin alone and in complex with mitochondrial thioredoxin reductase. (ii) investigate the structural and mechanistic features of essential glutathione homeostasis enzymes. The goal of this aim is to gain insight into the regulation of glutathione levels. We will examine the molecular details of allosteric regulation of glutamate cysteine ligase, which catalyzes the committed step of glutathione bisoynthesis. We will also examine the auto-activation mechanism of g-glutamyl transpeptidase, an ectoenzyme required for glutathione salvage, and the effects of self-processing on catalytic activity. Structural characterizations of these key thioredoxin and glutathione systems will provide new insights into mechanisms of cellular redox homeostasis. Understanding the crucial details may translate to new therapeutic targets in the array of difficult health problems caused by oxidative damage.

描述（由申请人提供）：有效的细胞内电子转移对于使用氧气的生物至关重要。必须仔细调节氧化和减少酶和辅助因子的氧化和辅助因子的精致平衡，以维持细胞功能。氧化还原平衡的丧失是与衰老和年龄相关疾病相关的分子变化。氧化还原稳态中急性或慢性破坏的后果包括神经退行性疾病，癌症，糖尿病，动脉粥样硬化和类风湿关节炎。为了研究控制氧化还原平衡的特定分子和化学事件，将检查保留细胞氧化还原电位的酶的结构和生化研究。尤其是，拟议的研究将考虑负责维持硫氧还蛋白和谷胱甘肽池减少的酶促途径，以解决以下特定目的：（i）表征分子水平的线粒体硫氧还蛋白还原酶催化的电子转移级联反应。该目的的目的是使用结构分析和生化特征来检查硫氧还蛋白系统的机械细节，因为它与线粒体氧化还原稳态有关。我们将单独确定线粒体硫氧还蛋白和谷蛋白的晶体结构，并与线粒体硫氧还蛋白还原酶复合体。 （ii）研究必需谷胱甘肽稳态酶的结构和机械特征。该目标的目的是深入了解谷胱甘肽水平的调节。我们将研究谷氨酸半胱氨酸连接酶的变构调节的分子细节，该调节催化了谷胱甘肽生物联合的构成步骤。我们还将检查G-谷氨酰基肽酶的自动激活机制，谷胱甘肽挽救所需的外酶，以及自我处理对催化活性的影响。这些关键硫氧还蛋白和谷胱甘肽系统的结构表征将提供有关细胞氧化还原稳态机制的新见解。了解关键细节可能会转化为因氧化损害引起的一系列困难健康问题的新治疗靶标。