Coordination of functions by proline metabolic proteins.

脯氨酸代谢蛋白的功能协调。

基本信息

批准号：
9115668
负责人：
JOHN J TANNER
金额：
$ 28.05万
依托单位：
UNIVERSITY OF MISSOURI-COLUMBIA
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-05-05 至 2019-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9115668
关键词：
Active Sites Amino Acids Awareness Bacteria Biological Book Chapters C-terminal Catabolism Cells Cellular Structures Citric Acid Cycle Communication Complex Crystallography Defect Deposition Disease Electron Transport Electrons Enzymatic Biochemistry Enzymes Eukaryota Evolution Exhibits Family Funding Genus Mycobacterium Glutamates Health Heart Helicobacter Human Hydrolysis Kinetics Knowledge Link Longevity Medical Membrane Proteins Metabolic Metabolic Diseases Metabolic Pathway Metabolism Modeling Molecular Organism Oxidoreductase Pathway interactions Phase Predisposition Production Proline Proline Dehydrogenase Property Proteins Publishing Reaction Reporting Research Roentgen Rays Role Scheme Schizophrenia Speed Structure System Time Tumor Suppression Virulence Virulence Factors Work abstracting aldehyde dehydrogenases alpha ketoglutarate base carbon skeleton carboxylate design enzyme substrate in vivo interest journal article member metabolic engineering molecular dynamics novel oxidation pathogen polypeptide prevent protein protein interaction pyrroline scaffold structural biology systems research

项目摘要

DESCRIPTION (provided by applicant): Metabolic enzymes in cells rarely function in isolation. Often their activities are coordinated by physical association with each other and cellular structures. A consequence of these associations is that metabolic intermediates do not equilibrate with the cellular milieu but rather are channeled between enzymes. Despite the widespread recognition that protein-protein interactions are ubiquitous, the mechanisms of substrate channeling remain relatively understudied and thus poorly understood. We help close this knowledge gap by exploring substrate channeling within and between the enzymes of proline catabolism. Proline catabolism comprises two enzymes and an intervening hydrolysis step. The flavoenzyme proline dehydrogenase (PRODH) catalyzes the oxidization of L-proline to 1-pyrroline-5-carboxylate (P5C). Hydrolysis of P5C yields L-glutamate--semialdehyde, which is oxidized to L-glutamate by the NAD+-dependent enzyme P5C dehydrogenase (P5CDH). These enzymes have been implicated in many aspects of human health and disease, including tumor suppression, hyperprolinemia metabolic disorders, schizophrenia susceptibility, life- span extension, and the virulence of fungal and bacterial pathogens. In some organisms, PRODH and P5CDH are combined into a single polypeptide chain known as proline utilization A (PutA). The packaging of sequential enzymes from a metabolic pathway into a single protein not only implies substrate channeling but also the possibility of protein-protein interactions between the monofunctional enzymes. Thus, proline catabolism affords an excellent opportunity to compare substrate channeling within and between enzymes. The next phase of this project builds upon three major accomplishments made during the previous funding cycle: determination of the first crystal structures of PutA proteins, discovery of a novel hysteretic substrate channeling kinetic mechanism, and uncovering the first evidence for inter-enzyme substrate channeling between monofunctional PRODH and P5CDH enzymes. The specific aims are to (1) elucidate the diverse structural solutions to substrate channeling that have evolved in the PutA family, (2) determine the structural basis and conservation of the hysteretic channeling mechanism, and (3) study substrate channeling in biological context by examining PRODH - P5CDH interactions in whole cells and determining the phenotypic consequences of disrupting proline metabolic channeling.

描述（由适用提供）：细胞中的代谢酶很少孤立地发挥作用。他们的活动通常通过彼此的身体关联和细胞结构进行协调。这些关联的结果是代谢中间体与细胞环境不相等，而是在酶之间引导。尽管蛋白质 - 蛋白质相互作用无处不在，但底物引导的机制仍然相对理解，因此理解较低。我们通过探索脯氨酸分解代谢酶内部和之间的底物引导来帮助缩小这一知识差距。脯氨酸分解代谢包括两种酶和一个中间的水解步骤。黄氧酶脯氨酸脱氢酶（PODH）催化L-丙啉氧化为1-吡frololine-5-羧酸盐（P5C）。 P5C的水解产生L-谷氨酸 - 甲醛，该甲醛被NAD+依赖性酶P5C脱氢酶（P5CDH）氧化为L-谷氨酸。这些酶在人类健康和疾病的许多方面都被浸渍，包括肿瘤抑制，高丙酸酯代谢性疾病，精神分裂症易感性，寿命扩展以及真菌和细菌病原体的病毒。在某些生物体中，PODH和P5CDH被合并为一个被称为脯氨酸利用A（PUTA）的单多肽链。顺序酶从代谢途径中包装到单个蛋白质中，不仅意味着底物通道，而且还意味着单官能酶之间蛋白质 - 蛋白质相互作用的可能性。这是脯氨酸分解代谢提供了一个极好的机会，可以比较酶内部和之间的底物通道。该项目的下一个阶段建立在上一个资金周期中取得的三个主要成就的基础：确定普塔蛋白的第一个晶体结构，发现一种新型的滞后底物通道动力学机制，以及发现单函数Prodh和P5CDH Enzyses之间的辅助底物底物的第一个证据。 The specific aims are to (1) elucidate the divers structural solutions to substrate channeling that have evolved in the PutA family, (2) determine the structural basis and conservation of the Hysteretic channeling mechanism, and (3) study substrate channeling in biologic context by examining PRODH - P5CDH interactions in whole cells and determining the phenotypic consequences of disrupting proline metabolic channeling.