Catalysis and biogenesis in methylamine dehydrogenase

甲胺脱氢酶的催化和生物发生

• 批准号: 6552820
• 负责人: CAROLINE MARY WILMOT
• 金额: $ 16.21万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6552820
• 关键词: Schiff bases; X ray crystallography; active sites; bacterial proteins; blastomycosis; catalyst; chemical binding; chemical transfer reaction; cofactor; colorimetry; electrospray ionization mass spectrometry; enzyme activity; enzyme biosynthesis; enzyme structure; freeze etching; methylamines; oxidation reduction reaction; oxidoreductase; protein structure function; tryptophan

DESCRIPTION (provided by applicant): Methylamine dehydrogenase (MADH) is an ancient bacterial metabolic enzyme that evolved in a pre-aerobic world. Its anaerobic origins are attested to by the highly evolved multistep chemistry it catalyzes, and its use of ancillary redox protein partners, rather than molecular oxygen, to remove electrons during catalysis. Although a product of divergent evolution, the reductive chemistry catalyzed by the enzyme is analogous to that of the copper-containing amine oxidase family, whose human counterparts are linked to late-diabetic complications and vascular changes in congestive heart disease. MADH contains a novel organic cofactor, tryptophan tryptophylquinone (TTQ), and study of its biogenesis will give new insight into how cofactors have evolved to extend the palette of chemistries enzymes can control: information that could aid in the development of new industrial catalysts, for example. Using a novel combination of single crystal visible spectroscopy, X-ray crystallography and freeze-trapping, this project will probe how the protein controls its complex multistep reaction at atomic resolution by trapping catalytic intermediates in Paracoccus denitrificans MADH (PD-MADH) containing crystals, and determining their structures. Collaborative mutagenesis/structural studies will be used to probe the roles of active site residues in catalysis, substrate binding and TTQ biogenesis. By studying this highly developed metabolic system, a part of the ancient anaerobic redox chemistries still found in mitochondria and chloroplasts today; we can shed light on the fundamental processes of harnessing energy and materials that evolved complex life on earth.

描述（由申请人提供）：甲胺脱氢酶（MADH）是一种古老的细菌代谢酶，它在野生恐惧症的世界中进化。它的厌氧起源得到了催化的高度进化的多步进化学的证明，以及在催化过程中使用辅助氧化还原蛋白伴侣而不是分子氧来去除电子。尽管酶催化的还原性化学与含铜胺氧化酶家族的还原性相似，但其人类的同龄人与晚期糖尿病并发症和充血性心脏病的血管变化有关。 MADH包含一种新型有机辅因子，色氨酸色氨酸酮（TTQ），对其生物发生的研究将使有关辅助因子如何发展以扩展化学酶的调色板可以控制的新见解可以控制：例如，可以帮助新工业催化剂开发的信息。使用单晶可见光谱，X射线晶体学和冻结捕获的新型组合，该项目将探测蛋白质如何通过捕获Denitrificans madh（PD-MADH）（PD-MADH）中的催化中间体来控制其复杂的多步反应，并包括晶体，并确定其结构。协作诱变/结构研究将用于探测活性位点残基在催化，底物结合和TTQ生物发生中的作用。通过研究这种高度发达的代谢系统，如今仍在线粒体和叶绿体中发现的古代厌氧氧化还原化学化学的一部分；我们可以阐明利用在地球上发展复杂寿命的能量和材料的基本过程。