Sulfide Oxidation and Signaling

硫化物氧化和信号传导

• 批准号: 10360743
• 负责人: RUMA V BANERJEE
• 金额: $ 6.95万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10360743
• 关键词: Address; Affect; Allosteric Regulation; Binding; Biochemical; Biogenesis; Blood Vessels; Catabolism; Cells; Coupled; Crystallization; Cystathionine beta-Synthase; Cysteine; Cysteine Desulfhydrase; Defect; Dioxygenases; Disease; Electron Spin Resonance Spectroscopy; Electron Transport; Environment; Enzymes; Failure; Foundations; Health; Heme; Homeostasis; Human; Hydrogen Sulfide; Inflammation; Kinetics; Medical; Mitochondria; Mutation; Oxidoreductase; Pathway interactions; Patients; Physiological; Proteins; Quinones; Reaction; Regulation; Research; Research Support; S-Adenosylmethionine; Schedule; Scientist; Signal Transduction; Signaling Molecule; Sulfides; Sulfur; Sulfur Metabolism Pathway; Thiosulfate Sulfurtransferase; Training; Work; mutant; neuroregulation; oxidation; persulfides; potentiometric titration; sulfite oxidase; sulfurtransferase

Hydrogen sulfide (H2S), a signaling molecule that elicits profound physiological effects, is a product of mammalian sulfur metabolism and is synthesized at relatively high rates. H2S is biosynthesized by three enzymes in the sulfur network of which two, cystathionine beta- synthase (CBS) and gamma-cystathionase, reside in the cytoplasmic transsulfuration pathway while the third, mercaptopyruvate sulfurtransferase, is involved in cysteine catabolism. Since H2S is highly toxic, cells avoid its build-up by an efficient oxidation pathway that is housed in mitochondria and coupled to the energy-generating electron transfer chain. The constituent proteins include sulfide-quinone oxidoreductase, a persulfide dioxygenase, rhodanese and sulfite oxidase. While our studies on H2S biogenesis are supported by HL58784, our work on H2S oxidation and signaling are supported by GM130183. It is becoming increasing clear that the biosynthetic and catabolic pathways for H2S interact and modulate each other. Therefore, the sulfide research supported by HL58784, scheduled to expire this year, will be folded into and then formally included in the competitive renewal of GM130183. In this supplemental project, the following specific aims will be addressed to elucidate fundamental mechanisms of regulation of H2S synthesis by CBS in normal and disease states: i) elucidate the steady state kinetics of linker mutants in CBS in the canonical transsulfuration and non-canonical H2S-generating reactions, (ii) investigate perturbations in the heme environment by EPR spectroscopy and potentiometric titrations, (iii) assess the impact of the mutations on AdoMet-dependent modulation of CO and NO• binding to ferrous heme and on the cellular flux of sulfur, and (iv) crystallize the linker mutants that appear to be less prone to aggregation compared to wild-type CBS. The impact of the proposed studies will be fundamental (i.e. elucidating mechanims of allosteric regulation at the level of CBS and in the pathway), medical (i.e. understanding the biochemical basis of failure of disease- causing CBS mutations), and most importantly, training a URM scientist of high promise.

硫化氢 (H2S) 是一种能引起深远生理效应的信号分子， 哺乳动物硫代谢的产物，合成速度相对较高。硫化氢 由硫网络中的三种酶生物合成，其中两种是胱硫醚β- 合成酶（CBS）和γ-胱硫醚酶，存在于细胞质转硫作用中 第三个途径是巯基丙酮酸硫转移酶，涉及半胱氨酸 分解代谢。由于 H2S 具有剧毒，细胞可以通过有效的氧化来避免其积聚 位于线粒体中并与产生能量的电子耦合的途径 转移链。组成蛋白质包括硫化物醌氧化还原酶、 过硫化物双加氧酶、硫氰酸酶和亚硫酸盐氧化酶。虽然我们对 H2S 的研究 生物发生得到 HL58784 的支持，我们在 H2S 氧化和信号传导方面的工作是 由 GM130183 支持。越来越明显的是，生物合成和 H2S 的分解代谢途径相互作用并相互调节。因此，硫化物 HL58784支持的研究计划于今年到期，将被合并到然后 正式纳入GM130183竞争性更新。在这个补充项目中， 将实现以下具体目标，以阐明基本机制： 正常和疾病状态下 CBS 对 H2S 合成的调节：i) 阐明稳定的 CBS 中典型转硫和非典型转硫过程中接头突变体的状态动力学 H2S 生成反应，(ii) 通过 EPR 研究血红素环境的扰动 光谱和电位滴定，(iii) 评估突变对 AdoMet 依赖性调节 CO 和 NO• 与亚铁血红素和细胞的结合 硫通量，以及（iv）使似乎不易发生的连接突变体结晶 与野生型 CBS 相比，聚集。拟议研究的影响将是 基础（即阐明 CBS 水平和中的变构调节机制） 途径），医学（即了解疾病失败的生化基础- 导致 CBS 突变），最重要的是，培养一位有前途的 URM 科学家。