COLLABORATIVE PROJECTS IN ENVIRONMENTAL HEALTH SCIENCES

工作总结：本项目包括群众参与的工作 光谱工作组与其他小组协作，包括内部和 在研究所之外解决共同感兴趣的问题。少校 这些项目的重点是：1)未知结构的确定 化合物；2)鉴定和/或确认生物途径； 3)量化；4)为结构制定战略 生物重要化合物的测定。当前专业 正在开展的合作项目包括：1)确定配体 孤儿受体(C.Weinberger，LRDT)和；2)定量 花生四烯酸代谢物(D.Zeldin，LPP)。量化： 花生四烯酸代谢产物--测定花生四烯酸最灵敏、准确的方法 生理样品中二十碳烷类化合物的选择离子定量 负离子化学电离(NICI)质量监测(SIM) 光谱分析。我们目前正在对环氧基和二羟基进行量化- 二十碳三烯酸。一个涉及量化的项目 环氧二十烷类化合物是对心肌细胞色素P450花生四烯酸的研究 酸性环氧酶途径(IRA)。在本研究中，一种新的P450单加氧酶， 命名为CYP2J3，已被测序和克隆。丰富的表达方式 已证实在大鼠心脏和肝脏中存在细胞色素P450 2J3。校长 花生四烯酸氧化产物经鉴定为14，15-11，12- 和8，9-环氧二十碳三烯酸和19-羟基二十碳四烯酸。 在灌流的缺血大鼠心脏中添加11，12-环氧二十碳三烯酸 酸导致回收率显著提高1.6倍 当14，15-环氧二十碳三烯酸和14，15-环氧二十碳三烯酸 19-羟基二十碳四烯酸有任何作用。其他项目 花生四烯酸环氧合酶代谢物的定量 包括哺乳动物CYP2J的酶途径的特征 P450单加氧酶亚家族。它的重组蛋白 该家族具有独特的酶学性质。这个 研究了这些蛋白质在哺乳动物组织中的分布。 以及它们在特定组织中的氧化产物。

Summary of Work: This project includes those endeavors in which the mass spectrometry workgroup collaborates with other groups, both inside and outside the Institute to solve problems of mutual interest. The major focuses of these projects are: 1) structure determination of unknown compounds; 2) identification and/or confirmation of biological pathways; 3) quantitation; and 4) development of strategies for the structure determination of biologically important compounds. Current major collaborative projects under way include: 1) identification of ligands for orphan receptors (C. Weinberger, LRDT) and; 2) quantitation of arachidonic acid metabolites (D. Zeldin, LPP). Quantitation of Arachidonic Acid Metabolites - The most sensitive and accurate method for quantitation of eicosanoids in physiological samples is by selected ion monitoring (SIM) under negative ion chemical ionization (NICI) mass spectrometry. We are currently quantifying epoxy- and dihydroxy- eicosatrienoic acids. One project that involves quantitation of epoxyeicosanoids is a study of the cardiac cytochrome P450 arachidonic acid epoxygenase pathway (IRA). In this study a new P450 monoxygenase, designated CYP2J3, has been sequenced and cloned. Abundant expression of CYP2J3 in rat heart and liver has been demonstrated. The principal arachidonic acid oxidation products have been identified as 14,15- 11,12- and 8,9-epoxyeicosatrienoic acids and 19-hydroxyeicosatetraenoic acid. In perfused, ischemic rat hearts, addition of 11,12-epoxyeicosatrienoic acid resulted in a significant 1.6 fold improvement in recovery of cardiac contractility while neither 14,15-epoxyeicosatrienoic acid nor 19-hydroxyeicosatetraenoic acid showed any effect. Additional projects involving quantitation of arachidonic acid epoxygenase metabolites include characterization of the enzyme pathways of mammalian CYP2J subfamily of P450 monooxygenases. The recombinant proteins of this family were found to possess distinct enzymological properties. The distribution of the proteins in mammalian tissues has been investigated as well as their oxidation products in the specific tissues.