COLLABORATIVE PROJECTS IN ENVIRONMENTAL HEALTH SCIENCES

工作总结：该项目包括那些努力，其中群众 光谱学与其他团体合作，无论是内部和 在研究所之外解决共同关心的问题。 主要 这些项目的重点是：1）未知结构的确定 2）生物学途径的鉴定和/或确认; 3)定量;和4）发展战略的结构 生物重要化合物的测定。当前重大 正在进行的合作项目包括：1）确定配体 对于孤儿受体（C. Weinberger，LRDT）和; 2）定量 花生四烯酸代谢物（D. Zeldin，LPP）。定量 花生四烯酸蛋氨酸-最灵敏和准确的方法 生理样品中类二十烷酸的定量是通过选择的离子 负离子化学电离质量监测（SIM） 光谱法 我们目前正在量化环氧和二羟基- 二十碳三烯酸 一个涉及定量的项目 epoxyeicosanoids是心脏细胞色素P450花生四烯酸的研究。 酸性环氧酶途径（伊拉）。 在这项研究中，新的P450单加氧酶， 命名为CYP 2 J3，已被测序和克隆。丰富的表达 CYP 2 J3在大鼠心脏和肝脏中已得到证实。 校长 花生四烯酸氧化产物已被鉴定为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。 在灌注的缺血大鼠心脏中，加入11，12-环氧二十碳三烯酸 酸导致回收率显著提高1.6倍， 心肌收缩力，而14，15-环氧二十碳三烯酸和 19-羟基二十碳四烯酸显示任何作用。 额外项目 包括花生四烯酸表氧化酶代谢物的定量 包括哺乳动物CYP 2 J酶途径的表征 P450单加氧酶亚家族。 这种重组蛋白 家族被发现具有不同的酶学性质。 的 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.