STRUCTURE FUNCTION & BIOSYNTHESIS OF RESPIRATORY ENZYMES

结构功能

• 批准号: 3299790
• 负责人: VICTOR L DAVIDSON
• 金额: $ 19.68万
• 依托单位: UNIVERSITY OF MISSISSIPPI MED CTR
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-01 至 1993-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3299790
• 关键词: Methanobacteriaceae; bacteria; cytochrome c; electron transport; enzyme biosynthesis; enzyme complex; enzyme mechanism; enzyme structure; flavoproteins; genetic translation; membrane permeability; membrane potentials; messenger RNA; metalloproteins; oxidation reduction reaction; protein biosynthesis; protein structure function; quinoline analog; respiratory enzyme

The objective of this proposal is to define the kinetic mechanisms and physiological roles of a variety of oxidoreductases and electron carrier proteins found in methylotrophic and autotrophic bacteria; and to exploit these bacteria as systems for the study of the molecular mechanisms of protein biosynthesis, export, and assembly. These soluble enzymes and proteins possess a variety of interesting redox centers including flavins, iron-sulfur centers, hemes, copper, and the novel pyrroloquinoline quinone (PQQ) cofactor; many are inducible and synthesized to very high levels; and many are exported to and function in the periplasmic space of these bacteria. The structural and physical properties of these redox proteins will be determined and the kinetics of the interactions of redox proteins which function in sequence will be analyzed. This will allow specific inferences to be drawn and tested concerning structure-function relationships which pertain to the mechanisms of intramolecular and intermolecular electron transport. The role of PQQ in catalysis by methylamine dehydrogenase will be defined. This will have broad significance in that the mammalian copper-containing amine oxidases, which play an important role in regulating the levels of biogenic amines, also possess PQQ. Each of the redox proteins to be studied is representative of families of proteins which are ubiquitous in nature. As such, the structural and functional analogies between these bacterial proteins and their eukaryotic counterparts will be characterized by physical, immunological, and kinetic analyses. In vitro translation and translocation systems will be developed to study the mechanisms by which the expression of these respiratory proteins are regulated, precursor proteins are processed, prosthetic groups are attached to apoproteins, multisubunit enzymes are assembled, and polypeptides are transported across biological membranes. This information should greatly enhance our understanding of the biogenesis of proteins which are involved in energy transduction and of exported proteins in general. As energy metabolism is vital to all living things, the proposed studies will be relevant to our understanding of a critical biological process.

该建议的目的是定义动力学机制 各种氧化还原酶和生理作用 在甲基营养和自养中发现的电子载体蛋白 细菌;并利用这些细菌作为研究的系统 蛋白质生物合成，出口和 集会。 这些可溶性酶和蛋白质具有多样性 有趣的氧化还原中心，包括黄素，铁硫心中心， hemes，铜和新型吡咯喹啉喹酮（PQQ） 辅助因子；许多是可诱导的，并合成至非常高的水平。 许多 这些细菌。 这些的结构和物理特性 将确定氧化还原蛋白，并将其动力学 氧化还原蛋白的相互作用将在序列中起作用 分析。 这将允许得出具体的推论，并 关于结构功能关系的测试 到分子内和分子间电子的机制 运输。 PQQ在甲胺催化中的作用 将定义脱氢酶。 这将具有广泛的意义 在那含哺乳动物铜的胺氧化酶，这是 在调节生物胺的水平中起重要作用， 也具有PQQ。 每个要研究的氧化还原蛋白是 无处不在的蛋白质家族的代表 自然。 因此，之间的结构和功能类比 这些细菌蛋白及其真核对应物将是 以物理，免疫学和动力学分析为特征。 体外翻译和转运系统将被开发为 研究这些表达的机制 调节呼吸蛋白，前体蛋白是 经过处理的假体组附在载脂蛋白上， 组装了多亚基酶，多肽是 跨过生物膜。 这些信息应该 极大地增强了我们对蛋白质生物发生的理解 参与能量转导和导出的 蛋白质一般。 由于能量代谢对于所有生活都至关重要 事物，拟议的研究将与我们的理解有关 关键的生物学过程。