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.

本提案的目的是确定动力学机制 和各种氧化还原酶的生理作用， 在甲基营养型和自养型中发现的电子载体蛋白 细菌;并利用这些细菌作为研究系统， 蛋白质生物合成、输出的分子机制， 组装件. 这些可溶性酶和蛋白质具有多种 有趣的氧化还原中心，包括黄素，铁硫中心， 血红素、铜和新型吡咯并喹啉醌（PQQ） 辅因子;许多是可诱导的，并合成到非常高的水平; 许多被输出到细胞的周质空间并在其中发挥作用 这些细菌。 这些化合物的结构和物理性质 氧化还原蛋白质将被确定和动力学的 氧化还原蛋白质的相互作用，在序列中发挥作用， 分析了 这将允许得出具体的推论， 关于结构-功能关系的测试， 分子内和分子间电子的机制 运输 PQQ在甲胺催化反应中的作用 脱氢酶将被定义。 这将具有广泛的意义 因为哺乳动物含铜胺氧化酶， 在调节生物胺的水平中起重要作用， 也有PQQ。 每一种要研究的氧化还原蛋白质都是 蛋白质家族的代表， 自然 因此，结构和功能之间的类比 这些细菌蛋白质和它们的真核对应物将被 通过物理学、免疫学和动力学分析表征。 将开发体外翻译和易位系统， 研究这些表达的机制， 呼吸道蛋白是受调节的，前体蛋白是 加工后的辅基附着在脱辅基蛋白上， 多亚基酶被组装，多肽被 通过生物膜运输。 这些信息应该 大大提高了我们对蛋白质生物起源的理解 参与能量转换和输出 蛋白质一般 因为能量代谢对所有生物都至关重要 事情，拟议的研究将与我们的理解有关， 一个关键的生物过程。