Structure Function & Biosynthesis of Respiratory Enzymes

这项研究项目涉及酶反应机制、蛋白质结构-功能关系、蛋白质-蛋白质相互作用、蛋白质生物合成和远程生物电子转移机制的研究。这些研究的结果有助于我们理解酶催化反应的机制，以及生物能量转导和呼吸的分子细节。拟议的研究主要集中在色氨酸色氨酸色酚[TTQ]承载酶，甲胺脱氢酶[MADH]，以及它与I型铜蛋白氨基蓝蛋白和细胞色素c-551I形成的电子转移络合物。该项目中的蛋白质已经以自由和复杂的形式结晶，并建立了通过定点突变改变蛋白质并分析其物理性质和生理功能的方案。这允许我们定义特定的结构-功能关系。阐明影响蛋白质间有效电子转移所需的特定蛋白质-蛋白质相互作用的因素，有助于深入了解蛋白质-蛋白质识别过程，这是一系列生物现象的共同特征。对藜麦蛋白催化反应机理的表征使我们能够更好地了解酶一般是如何催化反应的。分子间长程电子转移机制的定义将使我们在分子水平上更好地理解呼吸作用和中间代谢的基本过程。对MADH和TTQ生物合成机制的描述将有助于理解复杂氧化还原蛋白的生物合成机制，以及蛋白质生物合成和蛋白质翻译后修饰的一般机制。

This research project concerns the study of enzyme reaction mechanisms, protein structure-function relationships, protein-protein interactions, protein biosynthesis, and mechanisms of long range biological electron transfer. The results of these studies are helping us to understand mechanisms by which enzymes catalyze reactions, and the molecular details of biological energy transduction and respiration. The proposed studies focus on the tryptophan tryptophylquinone [TTQ] bearing enzyme, methylamine dehydrogenase [MADH], and the electron transfer complex it forms with the type I copper protein amicyanin, and cytochrome c-551i . The proteins in this project have been crystallized free and in complex, and protocols have been established for altering the proteins by site-directed mutagenesis and analyzing their physical properties and physiological functions. This allows us define specific structure-function relationships. Elucidation of factors which influence the specific protein-protein interactions that are required for efficient interprotein electron transfer is providing insight into the process of protein-protein recognition that is common to a wide range of biologic phenomena. Characterization of the catalytic reaction mechanisms of quinoproteins is allowing us to better understand how enzymes, in general, catalyze reactions. Definition of the mechanisms of long range intermolecular electron transfer will allow us to better understand the fundamental processes of respiration and intermediary metabolism at the molecular level. Description of the mechanism of biosynthesis of MADH and TTQ will be relevant to understanding the mechanisms of biosynthesis of complex redox proteins, as well as mechanisms of protein biosynthesis and posttranslational modification of proteins in general.