Hydrolytic enzymes in the metabolism of toxins

描述（由申请方提供）：外来化合物风险的评价取决于对参与其降解的酶的了解。一组未充分研究的代谢酶包括？/？-水解酶折叠家族这些酶通过加水来降解环氧化物。一些环氧化物具有反应活性和高度致突变性，并且环氧化物通常由来自各种环境化学品的细胞色素P450形成为代谢不稳定的官能团。环氧化物水解酶的水平不仅在人群中是可变的，而且它们可以被环境化学品和药物抑制或诱导。一个中心假设是，环氧化物水解酶也有内源性的作用。我们已经确定可溶性环氧化物水解酶也作用于花生四烯酸的环氧化物。这些是关键的调节脂质。事实上，我们在上一个资助期研制的可溶性环氧化物水解酶抑制剂正在进行治疗高血压的临床试验。由于可溶性环氧化物水解酶参与血压、炎症和疼痛的调节，因此它还代表了外源性物质作用的新靶点。同样，微粒体环氧化物水解酶的抑制导致急性异生物质毒性。关于？/？-折叠酶将通过完成两个主要目标来扩展，并且这里开发的工具对于测试关于可溶性环氧化物水解酶的内源性作用的一系列假设是至关重要的。目的我解决的结构和基本的生物化学环氧化物水解酶的研究较少的可溶性形式的主要重点。目的二继续发展代谢组学分析系统，以检查花生四烯酸级联反应和相关途径中的生物活性脂质。使用该分析平台以及酶的有效抑制剂和诱导剂，将评估可溶性环氧化物水解酶作为花生四烯酸级联中的关键酶的作用，从而评估炎症和疼痛的调节。沿着世界上15%的药物，普通的除草剂和个人护理产品也被认为对花生四烯酸级联反应起作用。例如，我们已经发现常见的肥皂抗菌剂三氯卡班是可溶性环氧化物水解酶和内源性肽血管紧张素沿着与过氧化物酶体增殖物激活受体的有效抑制剂。激动剂是诱导剂。通过解决我们的目标，知识将扩大对生物化学和作用的异源代谢的环氧化物水解酶。将测试环氧化物水解酶的内源性作用的假设，并将花生四烯酸级联作为外源性物质和营养品的作用位点进行评价。公共卫生相关性：环氧化物水解酶保护我们免受许多环境化学物质的侵害，其中一些还可以调节我们的血压，炎症和疼痛。这项研究将确定新的环氧化物水解酶的药物和保健品的行动，以改善健康的目标。这些知识也将预测来自增加或减少环氧化物水解酶水平的环境化学品的风险。

DESCRIPTION (provided by applicant): Evaluation of the risk of foreign compounds depends upon understanding the enzymes involved their degradation. A set of under-studied metabolic enzymes include the epoxide hydrolases in the ?/?-hydrolase fold family. These enzymes degrade epoxides by adding water. Some epoxides are reactive and highly mutagenic, and epoxides are commonly formed as metabolically labile functionalities by cytochrome P450s from variety of environmental chemicals. Not only are the levels of epoxide hydrolases variable in the human population, but they can be inhibited or induced by environmental chemicals and drugs. A central hypothesis is that epoxide hydrolases also have endogenous roles. We have established that the soluble epoxide hydrolase also acts on epoxides of arachidonic acid. These are key regulatory lipids. In fact, an inhibitor of the soluble epoxide hydrolase we made during the last grant period is in clinical trials to treat hypertension. Because the soluble epoxide hydrolase is involved in the regulation of blood pressure, inflammation and pain, it additionally represents a novel target for the action of xenobiotics. Similarly, inhibition of the microsomal epoxide hydrolase leads to acute xenobiotic toxicity. The knowledge of ?/?-fold enzymes will be expanded by completing two major objectives, and the tools developed here are critical to test a series of hypotheses regarding the endogenous role of the soluble epoxide hydrolase. Objective I addresses the structure and fundamental biochemistry of epoxide hydrolases with a major emphasis on the less studied soluble form. Objective II continues the development of a metabolomic profiling system to examine biologically active lipids in the arachidonate cascade and related pathways. Using this analytical platform as well as potent inhibitors and inducers of the enzyme, the role of the soluble epoxide hydrolase as a key enzyme in the arachidonate cascade and thus regulation of inflammation and pain will be evaluated. Along with 15% of the world's pharmaceuticals, common herbicides and personal care products are also known to act on the arachidonate cascade. For example we have found the common soap anti microbial, triclocarban, is a potent inhibitor of the soluble epoxide hydrolase and the endogenous peptide angiotensin along with PPAR? agonists are inducers. By addressing our objectives, knowledge will be expanded on the biochemistry and role in xenobiotic metabolism of epoxide hydrolases. The hypothesis of endogenous roles for epoxide hydrolases will be tested and the arachidonate cascade evaluated as a site of action for xenobiotics and nutraceuticals. PUBLIC HEALTH RELEVANCE: Epoxide hydrolase enzymes protect us against many environmental chemicals, and some of them also function to regulate our blood pressure, inflammation and pain. This study will identify new epoxide hydrolase targets for the action of drugs and nutraceuticals to improve health. This knowledge will also predict risk from environmental chemicals that increase or decrease the levels of epoxide hydrolases.