Peroxidation Profiles and Antioxidants

多不饱和脂肪酸(PUFAs)及其生物相关磷脂酯的过氧化 从单一分子物种产生数十种可能的产物的复杂反应。这个过程是一个 各种环境化学物质暴露、药物毒性和氧化应激的特征。除了……之外 由多不饱和脂类形成的许多过氧化产物，一组反应性亲电体也是 已生成。这些脂质过氧化的亲电残留物可以修饰核酸和蛋白质，在这个过程中 通过这种方式，脂质氧化降解的结果被分配到其他重要的生物分子。这 该提案概述了探索脂质过氧化的化学机制的实验，提供了一个 理解鱼油中存在的高度不饱和脂肪氧化的框架，描述了新的 用于分离脂质亲和蛋白加合物和检测新酚类的新亲和标记 比维生素E更有效的抗氧化剂高度不饱和的co-3多不饱和脂肪酸是比 更饱和的CO-6脂类，我们将通过分析过氧化来寻找这种差异的后果 模拟膜氧化及应激动物组织和体液对鱼油的生物标志物 节食。我们的亲和标记脂是在00位取代末端炔基的天然脂的类似物 脂肪酸链的位置(共yne)。该末端炔与生物素发生“点击”环加成反应 叠氮化物，允许将任何共价连接到脂类衍生亲电体的蛋白质下拉 带有(同音)的。这项拟议的研究是基于一种假设，即 脂质过氧化和亲电副产物的形成是这一过程的标志 理性地定义。当将亲和力标签与功能强大的高效液-质-质联用蛋白质组学方法结合使用时， 个别脂质-蛋白质加合物的结构鉴定，尽管这些物种只是 非常复杂的混合物。暴露在氧化应激下的人THP-1细胞的特征将包括在 这种亲和标记(辅基)脂类被结合到细胞中，从而允许分离脂蛋白加合物。 从磷脂中鉴定出的亲电体将构成合作筛选计划的基础 与计划项目的项目3和4合作。新的强效抗氧化剂将在《证据》中进行研究 概念“的活体啮齿动物实验。

Peroxidation of polyunsaturated fatty acids (PUFAs) and their biologically relevant phospholipid esters is a complex reaction giving scores of possible products from a single molecular species. This process is a hallmark of diverse environmental chemical exposures, drug toxicities and oxidative stresses. In addition to the many peroxide products that form from polyunsaturated lipids, a set of reactive electrophiles is also generated. These electrophilic residuals of lipid peroxidation modify nucleic acids and proteins and in this way, the consequence of lipid oxidative degradation is distributed to other important biomolecules. This proposal outlines experiments that probe the chemical mechanisms of lipid peroxidation, provides a framework for understanding the oxidation of highly unsaturated lipids present in fish oils, describes novel new affinity-tags useful in the isolation of lipid electrophile-protein adducts and examines new phenolic antioxidants more potent than vitamin E. Highly unsaturated co-3 PUFAs are better reducing agents than more saturated co-6 lipids and we will look for consequences of this difference by analyzing peroxidation biomarkers formed in model membrane oxidations and in tissues and fluids of stressed animals on fish oil diets. Our affinity-tag lipids are analogs of natural lipids having a terminal alkyne substituted at the 00 position (co-yne) of fatty acid chains. This terminal alkyne undergoes "click" cycloaddition with biotinsubstituted azides, permitting "pull-down" of any proteins covalently attached to lipid-derived electrophiles bearing an (co-yne). The proposed research is based on the hypothesis that the chemical mechanisms of lipid peroxidation and the formation of electrophilic byproducts that are a hallmark of this process can be rationally defined. The affinity tags when coupled to powerful HPLC/MS/MS proteomics methods permit the structural identification of individual lipid-protein adducts even though such species are only a small part of a very complex mixture. Profiling of human THP-1 cells exposed to an oxidative stress will include studies in which affinity tag (co-yne) lipids are incorporated into the cells, permitting isolation of lipid-protein adducts. The electrophiles identified from phospholipids will form the basis of a screening program in collaboration with Projects 3 and 4 of the Program Project. New powerful pyridinol antioxidants will be studied in "proof of concept" in vivo rodent experiments.