Production of Bioactive NO: Origin of Hemoglobin E Associated Pathophysiology

生物活性一氧化氮的产生：血红蛋白 E 的起源相关病理生理学

基本信息

批准号：
8206640
负责人：
JOEL M FRIEDMAN
金额：
$ 20.75万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-12-15 至 2013-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8206640
关键词：
Affinity Anemia Biological Availability Blood Vessels Cardiac Cardiovascular Physiology Cell membrane Cessation of life Chronic Clinical Coupling Data Databases Disease Erythrocytes Evaluation Exhibits Functional disorder Gel Heart Heart Diseases Hemoglobin Hemoglobin E Hemoglobin E Disease Hemoglobinopathies In Vitro Individual Induced Mutation Lead Ligands Light Link Mediating Membrane Mental Retardation Modeling Molecular Molecular Conformation Morbidity - disease rate Mutation Nitric Oxide Nitrite Reductase Nitrites Outcome Oxidation-Reduction Oxidative Stress Oxygen Pathologic Pathology Patients Play Production Property Proteins Protocols documentation Reaction Reactive Oxygen Species Relative (related person)Reporting Resolution Role Series Sickle Cell Anemia Source Structure Testing Thalassemia Therapeutic X-Ray Crystallography base innovation mutant novel programs protein structure therapy development

项目摘要

PROJECT SUMMARY & RELEVANCE Hemoglobin (Hb) E (¿E26K) is the most common worldwide naturally occurring mutant Hb with a mutation at the ¿1¿1 interface. EE individuals exhibit a mild, chronic anemia while HbE/¿-thalassemia individuals show a range of clinical manifestations, including high morbidity, and death, often resulting from cardiac dysfunction. The significant role of HbE in the red blood cell pathophysiology and molecular mechanisms giving rise to the HbE diseases is enigmatic. Since, HbE has been shown to have normal oxygen affinity (Bunn et al., 1972), we have proposed a possible mechanism whereby HbE may have reduced capacity to generate sufficient bioactive nitric oxide (NO) (1) to confer protection against high levels of membrane damaging reactive oxygen species (ROS) arising from the ¿-thalassemia and (2) as a secondary NO source for endothelial functioning. In support of this hypothesis we have obtained preliminary data from HbE showing decreased nitrite reductase activity compared to HbA. Our group recently obtained the high resolution deoxy and liganded HbE structures (Protein Data Bank entries 1YVQ, 1YVT, 3DUT) and found that the tertiary conformations within the T and R quaternary structures of HbE are altered relative to HbA. The proposed project which builds on these two findings, seeks to establish the extent and molecular origins of the altered nitrite reactivity. The project will utilize innovative sol-gel encapsulation protocols to trap and characterize the reactivity of the T and R state of HbE with respect to a series of reactions proposed to contribute to the production of bioactive NO. The project seeks to determine whether the source of HbE altered reactivity to generate bioactive forms of NO from nitrite arises from changes in allostery, in local tertiary structure or in the redox properties of the T and R states. These studies are of significance in that they are likely to provide a novel mechanism for the origin of HbE-derived pathophysiology with implications for other Hb related pathologies and diseases linked to endothelial dysfunction. There is the potential for a new paradigm in which to develop therapies for HbE ¿-thalassemia.

项目摘要与相关性血红蛋白（HB）E（E26K）是世界上最常见的自然存在的突变体Hb 在€1€1接口处的突变。 EE个体表现出温和的慢性贫血，而HBE/�-丘陵症个体显示一系列临床表现，包括高发病率和死亡，通常导致来自心脏功能障碍。 HBE在红细胞病理生理学和引起HBE疾病的分子机制是神秘的。从那以后，HBE已被证明具有正常的氧亲和力（Bunn等，1972），我们提出了一种可能的机制 HBE可能会降低产生足够的生物活性一氧化氮（NO）（1）到会议的能力保护高水平的膜破坏活性氧（ROS） - - 甲性贫血和（2）作为内皮功能的次要来源。支持这个假设我们从HBE获得了初步数据，显示了亚硝酸盐的降低活性与HBA相比。我们的小组最近获得了高分辨率脱氧和配体HBE结构（蛋白质数据库条目1yvq，1yvt，3dut），发现t内的三级构型 HBE的第四纪结构相对于HBA发生了变化。拟议的项目以这两个发现旨在建立改变的亚硝酸盐反应性的程度和分子起源。该项目将利用创新的Sol-Gel封装协议来捕获和表征反应性 HBE的T和R状态相对于提出的一系列反应，以促进生物活性编号的生产。该项目旨在确定HBE的来源是否改变了反应性产生来自亚硝酸盐的NO的生物活性形式，是由局部变化的变化引起的第三级结构或T和R状态的氧化还原特性。这些研究在他们很可能为HBE衍生的病理生理的起源提供一种新颖的机制对与内皮功能障碍相关的其他HB相关病理和疾病的影响。有新范式开发HBE®-甲性疾病的疗法的潜力。