Accelerated NO/02 Reactions in Low Density Lipoprotein

这项研究将主要在乌拉圭蒙得维的亚共和国大学理学院物理生物化学实验室以及医学院生物化学系与Denicola博士合作进行，作为NIH拨款1 R01 HL074391-02的延伸；7/10/03 - 6/30/07。在这个FIRCA申请中描述的实验目标解决了在西方国家发病率和死亡率的主要来源——动脉粥样硬化的基本机制。具体来说，在母体拨款中出现的问题，疏水相如何影响NO与O2反应的动力学和机制，将考虑到临床相关的疏水环境：低密度脂蛋白（LDL）。据推测，循环LDL的疏水隔室催化和聚焦NO与O2的反应，产生二次亚硝基（RNO）和硝化（RNO2）产物，翻译NO的细胞信号传导作用。具体来说，我们提出了一种机制理论来研究生物条件下亚硝化与硝化的相对变化。为了解决这一概念，将追求两个关键的实验目标：1)描述动力学，机制和LDL颗粒内NO/O2反应的新产物形成（亚硝化和硝化）；2)确定血管信号传导作用。（血管舒张和血管抗炎作用）。拟议的研究将为理解NO和O2反应对LDL氧化和随后的动脉粥样硬化事件的影响的机制基础，特别是对血管炎症的影响提供坚实的基础。

This research will be done primarily in Uruguay at the Physical Biochemistry Laboratory, School of Science as well as the Biochemistry Department, School of Medicine at the University of the Republic, Montevideo, in collaboration with Dr. Denicola as an extension of NIH grant 1 R01 HL074391-02; 7/10/03 - 6/30/07. The experimental goals described in this FIRCA application address fundamental mechanisms underlying the principal source of morbidity and mortality in westernized countries, atherosclerosis. Specifically, the questions arose in the parent grant, how hydrophobic phases influence the kinetics and mechanism of NO reaction with O2, will be extended considering a clinically relevant hydrophobic environment:: the low density lipoprotein (LDL). It is hypothesized that the hydrophobic compartment of circulating LDL serves to catalyze and focus the reaction of NO with O2, yielding secondary nitroso (RNO) and nitrated (RNO2) products that translate the cell signaling actions of NO. Specifically, a mechanistic rationale is proposed for examining a relative shift in nitrosation vs. nitration under biological conditions. To address this concept, two key experimental aims will be pursued: 1) delineate the kinetics, mechanisms and novel product formation (nitrosation and nitration) from NO/O2 reaction within the LDL particle, and 2) identify the vascular signaling actions.(vasodilation and vascular anti-inflammatory action) of the NO/O2-modified LDL. The proposed investigations will provide a strong foundation for understanding the mechanistic basis of the effects of NO and O2 reaction on LDL oxidation and consequent atherogenic events in particular, and on vascular inflammation in general.