PEROXYNITRITE AND NITROTYROSINE IN HEART DISEASE

描述：过氧亚硝酸盐（ONOO-）由扩散限制反应形成 超氧化物与一氧化氮是一个主要的机制，氧化损伤， 心脏 离体心肌暴露于微摩尔浓度 过氧亚硝酸盐仅仅几分钟就表现出许多病理性的 临床心脏病特征的变化，包括损伤 线粒体，收缩功能丧失和不可逆的增加， 舒张期僵硬 过氧亚硝酸盐侵蚀的主要后果之一 是特定蛋白质中酪氨酸残基的选择性硝化。 大鼠心肌缺血/再灌注过程中心肌细胞的快速硝化 和抑制一氧化氮的产生都能保护心肌功能 并减少酪氨酸硝化。 在人类的心脏中， 心肌缺血、脓毒症和心肌炎后出现心肌细胞硝化。 定量HPLC分析显示，1-7%的蛋白质结合的酪氨酸是 在脓毒症患者的硝化，显示硝化是一个重要的病理 人类的过程。 蛋白质印迹表明，一个令人惊讶的有限 许多蛋白质易受过氧亚硝酸盐的酪氨酸硝化作用的影响。 首席研究员已经证明锰超氧化物歧化酶， 肌动蛋白和中间丝在人类尸检材料中被硝化， 这些蛋白质的功能被过氧亚硝酸盐显著削弱 体外 电喷雾质谱分析表明过氧亚硝酸根 优先硝化亲水区的某些酪氨酸基序 与许多结构蛋白质相同。 首席研究员假设 过氧亚硝酸盐对结构蛋白的酪氨酸硝化作用 心肌损伤。 他的第一个目标是定量评估 缺血大鼠心脏中酪氨酸亚硝化的大小， 使用他们开发的一种新型探针测量过氧亚硝酸盐。 第二 目的是确定在大鼠和人类中哪些特定蛋白质被硝化 并通过串联质谱法确定这些中的酪氨酸 蛋白质被硝化。 第三个目的是表征硝化如何 影响肌动蛋白和其他结构蛋白的功能， 硝化作用如何影响肌收缩蛋白。 这些研究是新的 和新的方法来理解特定的机制， 生物产生的氧化剂会伤害心脏， 过氧亚硝酸盐攻击的主要目标在体内。

DESCRIPTION: Peroxynitrite (ONOO-) formed by the diffusion-limited reaction of superoxide with nitric oxide is a major mechanism of oxidative damage in the heart. Isolated heart muscle exposed to micromolar concentrations of peroxynitrite for only a few minutes exhibit many of the pathological changes characteristic of clinical heart disease, including injury to mitochondria, loss of contractile function and irreversible increases in diastolic stiffness. One of the major consequences of peroxynitrite attack is the selective nitration of tyrosine residues in specific proteins. Myocytes in rat heart become nitrated quickly during ischemia/reperfusion and inhibition of nitric oxide production both preserves myocardial function and reduces tyrosine nitration. In the human heart, similar patterns of myocyte nitration occur after ischemia, sepsis and myocarditis. Quantitative HPLC analysis revealed 1-7% of protein-bound tyrosines are nitrated in septic patients, showing nitration is a significant pathological process in humans. Western blots demonstrate that a surprisingly limited number of proteins are vulnerable to tyrosine nitration by peroxynitrite. The principal investigator has shown that manganese superoxide dismutase, actin and intermediate filaments are nitrated in human autopsy material and that the function of these proteins is markedly diminished by peroxynitrite in vitro. Electrospray mass spectrometry has revealed that peroxynitrite preferentially nitrates certain tyrosine motifs in hydrophilic regions common to many structural proteins. The principal investigator hypothesizes that tyrosine nitration of structural proteins by peroxynitrite contributes to myocardial injury. His first aim is to quantitatively assess the magnitude of tyrosine nitrosation in ischemic rat heart and to directly measure peroxynitrite using a novel probe they have developed. The second aim is to identify which specific proteins are nitrated in rat and human heart and determine by tandem mass spectrometry which tyrosines in these proteins are nitrated. The third aim is to characterize how nitration affects the function of actin and then other structural proteins to assess how nitration can affect myocontractile proteins. These studies are a new and novel approach to understanding the specific mechanisms by which biologically generated oxidants injure the heart and allow us to identify major targets for peroxynitrite attack in vivo.