Thiol/Disulfide Redox Regulation of Heme Oxygenase-2

血红素加氧酶 2 的硫醇/二硫化物氧化还原调节

• 批准号: 7985909
• 负责人: Stephen Wiley Ragsdale
• 金额: $ 54.45万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7985909
• 关键词: Address; Affect; Affinity; Azides; Bacteria; Biliverdin reductase; Biliverdine; Binding; Binding Sites; Biogenesis; Blood; C-terminal; Calorimetry; Carotid Body; Catabolism; Catalytic Domain; Cell Respiration; Cells; Cysteine; Cytoplasmic Structures; Cytoplasmic Tail; Disulfides; Drug or chemical Tissue Distribution; Electrophysiology (science); Embryo; Environmental air flow; Enzymes; Exhibits; Figs - dietary; Fluorescence; Gap Junctions; Genetic; Hand; Heme; Heme Iron; Homeostasis; Human; Hypoxia; Immunoprecipitation; In Vitro; Ion Channel; Iron; Kinetics; Length; Ligands; Link; Lipid Peroxidation; Location; Mammals; Measurement; Measures; Membrane; Metabolism; Metals; Methods; NADPH-Ferrihemoprotein Reductase; Neurons; Organ; Organism; Oxidation-Reduction; Oxygen; Oxygenases; Physiological; Play; Positioning Attribute; Potassium Channel; Process; Property; Protein Biosynthesis; Protein Isoforms; Proteins; Regulation; Research; Respiration; Respiratory System; Reticulocytes; Roentgen Rays; Role; Signal Transduction; Source; Structure; Sulfhydryl Compounds; System; Testis Brain; Titrations; Variant; Work; adduct; catalyst; cell growth regulation; circular magnetic dichroism; cysteinylproline; design; electronic structure; experience; heme a; heme oxygenase-1; heme oxygenase-2; in vivo; insight; kidney cell; large-conductance calcium-activated potassium channels; link protein; oxidative damage; public health relevance; research study; response; vector

DESCRIPTION (provided by applicant): Heme oxygenase (HO) catalyzes the conversion of heme to biliverdin, CO, and iron. The two isoforms, HO1 and HO2, share similar physical and kinetic properties but exhibit different physiological roles and organ locations. The structures of the core catalytic domains of HO1 and HO2 are nearly superimposable and the major distinction between these HO isoforms is the occurrence of heme regulatory motifs (HRMs) in HO2 that are lacking in HO1. The HRMs play a regulatory role as a thiol/disulfide redox switch that we have shown to regulate interactions of HO2 with substrate (heme) and with a Ca++- activated high conductance potassium channel (the BK or Slopoke channel). Regulation of K+ flux across the membrane by the BK channel enables the O2 sensing function of the carotid body, which controls respiratory system ventilation in response to changes in the blood oxygen concentration. We recently demonstrated that the BK channel also contains a thiol/disulfide redox switch that regulates binding of heme, which has been shown to control its K+ channel activity. We plan to use spectroscopic, kinetic, genetic, crystallographic, NMR, and electrophysiology methods to determine how these thiol/disulfide redox switches (the HRMs in human HO2 and the CXXC motif in the human BK channel) affect the structure and function of and interactions between these functionally linked proteins. We will determine the redox states of the heme and HRMs in vitro and in vivo under various physiological conditions. We also will perform spectroscopic and electrophysiology measurements to determine the mechanism by which HO2 influences BK channel function. PUBLIC HEALTH RELEVANCE: Heme oxygenase (HO) is the only mammalian protein known to degrade heme and sits at the nexus of several major redox and metal regulatory systems. Unlike HO1, HO2 contains two Heme Regulatory Motifs (HRMs) that form a thiol/disulfide redox switch, which regulates binding of its substrate, heme. We propose to determine how thiol/disulfide redox switches on HO2 and on a functionally related interacting partner, a heme-regulated potassium channel, regulate their structures and functions.

描述（由申请人提供）：血红素加氧酶（H2O）催化血红素转化为胆绿素、CO和铁。 HO1 和 HO2 两种异构体具有相似的物理和动力学特性，但表现出不同的生理作用和器官位置。 HO1 和 HO2 的核心催化结构域的结构几乎是重叠的，这些 HO 亚型之间的主要区别是 HO2 中出现了 HO1 所缺乏的血红素调节基序 (HRM)。 HRM 作为硫醇/二硫化物氧化还原开关发挥调节作用，我们已证明它可以调节 HO2 与底物（血红素）以及 Ca++ 激活的高电导钾通道（BK 或 Slopoke 通道）的相互作用。 BK 通道对跨膜 K+ 通量的调节启用了颈动脉体的 O2 传感功能，该功能可根据血氧浓度的变化来控制呼吸系统通气。我们最近证明，BK 通道还包含调节血红素结合的硫醇/二硫化物氧化还原开关，该开关已被证明可以控制其 K+ 通道活性。我们计划使用光谱、动力学、遗传、晶体学、核磁共振和电生理学方法来确定这些硫醇/二硫键氧化还原开关（人HO2中的HRM和人BK通道中的CXXC基序）如何影响这些功能性连接蛋白的结构和功能以及之间的相互作用。我们将在各种生理条件下测定体外和体内血红素和 HRM 的氧化还原状态。我们还将进行光谱和电生理学测量，以确定 HO2 影响 BK 通道功能的机制。 公共健康相关性：血红素加氧酶 (HO) 是唯一已知能降解血红素的哺乳动物蛋白质，位于几个主要氧化还原和金属调节系统的联系处。与 HO1 不同，HO2 包含两个血红素调节基序 (HRM)，形成硫醇/二硫化物氧化还原开关，调节其底物血红素的结合。我们建议确定硫醇/二硫化物氧化还原如何在 HO2 和功能相关的相互作用伙伴（血红素调节钾通道）上进行开关，从而调节其结构和功能。