Molecular Basis of Propionate Toxicity

丙酸盐毒性的分子基础

• 批准号: 7677204
• 负责人: JORGE C ESCALANTE
• 金额: $ 21.5万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-12 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7677204
• 关键词: 2-methylcitrate; Acetates; Acyl Coenzyme A; Acylation; Address; Affect; Anabolism; Animal Model; Animals; Archaea; Bacteria; Biochemical; Biochemical Pathway; Biological; Carbon; Catabolism; Cell Wall; Cell physiology; Cells; Chemistry; Chromosomes; Citrate (si)-Synthase; Citric Acid Cycle; Coenzymes; Communicable Diseases; Complex; Data; Ensure; Enzymes; Ethanolamines; Eukaryota; Food Preservatives; Gastrointestinal tract structure; Gene Expression; Genes; Genetic; Gluconeogenesis; Glucose; Growth; Growth Inhibitors; Health; Histones; Human; Isomerism; Knowledge; Laboratories; Learning; Ligase; Light; Metabolic; Metabolism; Microbe; Molecular; Molecular Genetics; Mutation; Nucleic Acids; Phenotype; Physiological; Play; Prevention; Prokaryotic Cells; Propionates; Propylene Glycols; Proteins; Publishing; Research Personnel; Ribose; Role; Salmonella enterica; Sirtuins; Soil; Solid; Source; Substrate Specificity; System; Toxic effect; Volatile Fatty Acids; Work; base; cell growth; cobamamide; deacylation; enzyme activity; fatty acid metabolism; gene function; gut microflora; inhibitor/antagonist; insight; interdisciplinary approach; interest; nutrition; pathogen; prevent; propionyl-coenzyme A; public health relevance; stereochemistry

DESCRIPTION (provided by applicant): Propionate is a three-carbon short-chain fatty acid that is very abundant in soil and the gastrointestinal tracts of animals, including humans. Propionate is widely used as a food preservative because it inhibits the growth of pathogenic and non-pathogenic prokaryotes and lower eukaryotes, but it does not affect human cells. The inhibitory effects of propionate have been attributed to the build up of the activated form of propionate, i.e., propionyl-coenzyme A (Pr-CoA). We have challenged this idea on the basis of published and unpublished data obtained from our group. In this application we propose to investigate the molecular basis of propionate toxicity. Our interpretation of the data suggests that growth arrest caused by propionate is the result of the synthesis of a non-physiological isomer of 2-methylcitrate by the citrate synthase (GltA) enzyme of the Krebs cycle; we refer to this inhibitor as 2-MCGltA. Our data suggest that 2-MCGltA inhibits an enzyme of gluconeogenesis. The lack of glucose has multiple negative effects. For example, cell wall and ribose syntheses are blocked, rendering the cell sensitive to osmotic changes and unable to make nucleic acids and coenzymes. One specific aim focuses on the identification and characterization of the target of 2-MCGltA. We seek to learn how 2-MCGltA inhibits the activity of the target, and whether the inhibitory effect of 2-MCGltA is stereospecific. A second specific aim focuses on the identification and analysis of ancillary functions needed to prevent propionate toxicity, and proteins involved in transporting propionate into the cell. PUBLIC HEALTH RELEVANCE: The project proposed in this application will provide insights into how propionate (a food preservative) exerts its inhibitory effects on cell growth at the molecular level. This work is relevant to human health and nutrition since propionate affects pathogenic and non-pathogenic microbes alike.

描述（由申请人提供）：丙酸盐是一种三碳短链脂肪酸，在土壤和动物（包括人类）的胃肠道中含量非常丰富。丙酸盐被广泛用作食品防腐剂，因为它抑制致病性和非致病性原核生物和低等真核生物的生长，但不影响人体细胞。丙酸盐的抑制作用归因于激活形式的丙酸盐的积累，即，丙酰辅酶A（Pr-CoA）。我们根据从我们小组获得的已发表和未发表的数据对这一想法提出了质疑。在这个应用程序中，我们建议调查丙酸毒性的分子基础。我们对数据的解释表明，丙酸盐引起的生长停滞是由克雷布斯循环的柠檬酸合酶（GltA）合成2-甲基柠檬酸盐的非生理异构体的结果;我们将这种抑制剂称为2-MCGltA。我们的数据表明，2-MCGltA抑制一种酶的同源性。缺乏葡萄糖有多种负面影响。例如，细胞壁和核糖合成受阻，使细胞对渗透压变化敏感，不能制造核酸和辅酶。一个具体的目标集中于2-MCGltA的靶标的鉴定和表征。我们试图了解2-MCGltA如何抑制靶标的活性，以及2-MCGltA的抑制作用是否是立体特异性的。第二个具体目标集中在识别和分析所需的辅助功能，以防止丙酸毒性，和蛋白质参与运输丙酸进入细胞。公共卫生关系：本申请中提出的项目将深入了解丙酸盐（一种食品防腐剂）如何在分子水平上对细胞生长产生抑制作用。这项工作与人类健康和营养有关，因为丙酸盐会影响致病性和非致病性微生物。