Regulation of NADH: ubiquinone oxidoreductase (complex *

NADH 的调节：泛醌氧化还原酶（复合物 *

• 批准号: 6645480
• 负责人: Gary Cecchini
• 金额: $ 4.28万
• 依托单位: NORTHERN CALIFORNIA INSTITUTE/RES/EDU
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6645480
• 关键词: Commonwealth of Independent States; NAD(P)H oxidoreductase; SDS polyacrylamide gel electrophoresis; active sites; binding sites; complementary DNA; cooperative study; enzyme structure; enzyme substrate; laboratory rat; ligands; mitochondria; mutant; myocardial ischemia /hypoxia; nucleic acid sequence; protein purification; reperfusion; ubiquinone

DESCRIPTION (provided by applicant) NADH:ubiquinone oxidoreductase (complex I) is an energy-transducing membrane-bound protein complex that serves as a major entry point for electrons to the mitochondrial respiratory chain. The multisubunit enzyme complex is encoded by 43 separate genes in mammals. The mammalian enzyme shows extremely complex kinetic behavior, in all forms that retain natural electron transfer pathways. The complex kinetic behavior suggests that two distinct slowly equilibrating forms of the enzyme exist. The active (A) form is catalytically capable to reduce ubiquinone, whereas, the de-active (D) form is not able to transfer electrons to ubiquinone in the membrane. The equilibrium between these two forms is under a refined control by a number of regulatory factors (i.e., pH, divalent cations, temperature, the ubiquinone/ubisemiquinone/ubiquinol ratio). This research will primarily be done in Russia as an extension of NIH grant R01 GM61606. The proposed collaborative work is to extend studies of the regulatory characteristics of the enzyme at the molecular mechanistic level by using a combination of biochemical and molecular approaches. The studies will be done in physiologically relevant systems such as intact hearts and mitochondria, as well as, the kinetic and biochemical approaches in the foreign Co-P.l.'s laboratory. Two major aspects of the ND transition are to be investigated. One is to elucidate the molecular mechanisms of the slow interconversion between the A and D forms involved in the red/ox-dependent D to A transition; and the extremely temperature-dependent A to D transition. Natural ligands and modifiers which affect the rate and equilibrium of the ND transition in vitro will be identified. The second aim focusses on the complex I A/D transition in intact mitochondria in relation to the experimental model of ischemia/reperfusion in Langendorff-pertused rat hearts. The focus of these studies is to determine the possible physiological importance of the A/D transition of complex I as it responds to alterations in cellular metabolism. The catalytic activity of complex I is important for cellular physiology and a number of diseases (diabetes, cardiomyopathy) have been associated with defects in complex I. The research to be undertaken will shed light on the modulation of enzyme activity of this important respiratory complex.

描述（由申请人提供）NADH：泛氨基氧化还原酶（复合物I）是一种能量转换膜结合的蛋白质复合物，是电子对线粒体呼吸链的主要入口处。多亚基酶复合物在哺乳动物中由43个单独的基因编码。哺乳动物酶在保留自然电子转移途径的所有形式中显示出极其复杂的动力学行为。复杂的动力学行为表明，存在两个不同的缓慢平衡酶的形式。活性（a）形式具有催化能力，能够减少泛氨基酮，而De-Active（D）形式无法将电子转移到膜中的泛氨基酮。这两种形式之间的平衡受到许多调节因素（即pH，二价阳离子，温度，泛氨基酮/泛氨基氨基酮/泛质比的比率）的精致控制。这项研究将主要在俄罗斯进行，以扩展NIH Grant R01 GM61606。提出的协作工作是通过使用生化和分子方法的组合，扩展分子机械水平上酶的调节特征的研究。这些研究将在生理相关的系统中进行，例如完整的心脏和线粒体，以及外国Co-L。实验室中的动力学和生化方法。 ND过渡的两个主要方面将进行研究。一种是阐明与红色/牛的依赖性d涉及过渡的a和d形式之间缓慢互连的分子机制；以及极度依赖温度的a到d转变。将确定影响ND过渡的速率和平衡的天然配体和修饰符。第二个目的集中在完整线粒体中的复合物I A/D转变上，相对于Langendorff-Pertsed大鼠心脏中缺血/再灌注的实验模型。这些研究的重点是确定复合物i的A/D过渡的生理重要性，因为它对细胞代谢的改变做出了反应。复合物I的催化活性对于细胞生理很重要，许多疾病（糖尿病，心肌病）与复合物I中的缺陷有关。