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是一个重要的研究领域。 一个复杂的反应，从单一的分子种类中产生许多可能的产物。这个过程是一 这是多种环境化学品暴露、药物毒性和氧化应激的标志。除了 由多不饱和脂质形成的许多过氧化物产物中，还存在一组反应性亲电体， 生成的.脂质过氧化的这些亲电残余物修饰核酸和蛋白质，并且在这种情况下， 另一方面，脂质氧化降解的后果被分配到其他重要的生物分子。这 提案概述了探索脂质过氧化化学机制的实验，提供了一个 的框架，用于理解鱼油中存在的高度不饱和脂质的氧化，描述了新的 用于分离脂质亲电蛋白加合物和检测新酚类化合物的新亲和标记物 比维生素E更有效的抗氧化剂。高度不饱和的co-3 PUFA是比 更多饱和的co-6脂质，我们将通过分析过氧化作用来寻找这种差异的后果。 在模型膜氧化和鱼油应激动物的组织和体液中形成的生物标志物 节食。我们的亲和标签脂质是天然脂质的类似物，其末端炔在00位被取代 脂肪酸链的位置（co-炔）。该末端炔与生物素取代的炔进行“点击”环加成反应， 叠氮化物，允许共价连接到脂质衍生的亲电体的任何蛋白质的“下拉” 有一个（co-yne）。这项研究是基于这样一个假设，即： 脂质过氧化和亲电子副产物的形成是该过程的标志， 理性定义。当与强大的HPLC/MS/MS蛋白质组学方法偶联时， 单个脂质-蛋白质加合物的结构鉴定，即使这些物质只是 非常复杂的混合物。对暴露于氧化应激的人THP-1细胞的分析将包括以下研究： 所述亲和标记（co-yne）脂质被掺入细胞中，从而允许分离脂质-蛋白质加合物。 从磷脂中鉴定出的亲电体将构成合作筛选计划的基础 项目3和项目4的项目。新的强大的吡啶醇抗氧化剂将在“证明 概念”在体内啮齿动物实验。

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.