DESIGN OF INHIBITORS OF EPINEPHRINE BIOSYNTHESIS

肾上腺素生物合成抑制剂的设计

• 批准号: 2217479
• 负责人: GARY L GRUNEWALD
• 金额: $ 22.87万
• 依托单位: UNIVERSITY OF KANSAS LAWRENCE
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-06-01 至 1997-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2217479
• 关键词: DESIGN; INHIBITORS; EPINEPHRINE; BIOSYNTHESIS

Phenylethanolamine N-methyltransferase (PNMT, E.C. 2.1.1.28) is the enzyme that catalyzes the terminal step in the biosynthesis of epinephrine. Increased levels of this enzyme are found during periods of stress and in hypertension. Epinephrine has been implicated in a number of neuroregulatory processes in the brain. We (and others) have demonstrated that inhibitors of PNMT can lower blood pressure in spontaneously hypertensive rats. However, all of the inhibitors presently available have high affinity for alpha2-adrenergic receptors that could contribute significantly to the observed pharmacological effects. We have previously synthesized a number of probes to determine the active site binding requirements for PNMT and have used this information to develop a computer graphics model of the active site. The model has been used to design new ligands for synthesis that, based on preliminary studies, have the potential of exhibiting the desired level of selectivity for the PNMT active site over the alpha-adrenergic receptor. These new ligands will be synthesized and evaluated for their affinity and selectivity for PNMT. The results will be incorporated into an improved computer model of the active site of PNMT, and will also be used to construct a complementary model of the alpha-adrenergic receptor. In addition, we will continue our highly successful studies employing the transferred nuclear Overhauser enhancement method to determine the conformation of a few key inhibitors and substrates when bound to the active site of PNMT. The nmr conformational information will allow improvement of the predictive utility of the computer model. We will also do affinity labeling of amino acid residues at the active site and use this information, in conjunction with knowledge-based homology modeling, to construct a possible three- dimensional model of the enzyme. A sufficient quantity of pure PNMT will be obtained from bovine adrenals to allow attempts at crystallization of the enzyme and a determination of its X-ray crystal structure. Molecular biology experiments are proposed that will allow us to obtain human adrenal PNMT and possibly human brain PNMT in quantities sufficient to evaluate potential inhibitors using the more relevant human enzyme and also to attempt crystallization and X-ray crystal structure determination of it. Results from all sub-projects will be combined in a synergistic fashion to lead to the synthesis of a highly potent and selective inhibitor of PNMT. Such an inhibitor would be a useful pharmacological tool to probe the role played by epinephrine in the central nervous system, and, in particular, potentially identify a new mechanism for drug treatment of hypertension.

苯乙醇胺N-甲基转移酶(PNMT，E.C.2.1.1.28)是 这催化了肾上腺素生物合成的最后一步。 这种酶的水平在压力时期和在 高血压。肾上腺素被认为与许多 大脑中的神经调节过程。我们(和其他人)已经证明了 PNMT抑制剂可自发降压 高血压大鼠。然而，目前所有可用的抑制剂都有 对α2肾上腺素能受体的高亲和力可能有助于 对观察到的药理作用有显著影响。我们之前已经 合成多个探针以确定活性部位结合 PNMT的要求，并利用这些信息开发了一台计算机 活动站点的图形模型。该模型已被用于设计新的 用于合成的配体，根据初步研究，具有 展示PNMT所需的选择性水平的潜力 α-肾上腺素能受体上的活性部位。这些新的配体将是 合成并评价了它们对PNMT的亲和力和选择性。这个 结果将被合并到一个改进的计算机模型中 PNMT的地点，并将用于构建一个补充模型 α-肾上腺素能受体。此外，我们将继续保持高度的 使用转移的核Overhauser的成功研究 增强法测定几种关键抑制剂的构象 和底物结合到PNMT的活性部位。核磁共振 构象信息将允许改进预测 计算机模型的效用。我们还将进行氨基酸的亲和标记 活性部位的酸残基，并结合使用此信息 利用基于知识的同源建模，构建可能的三个同源模型 酶的空间模型。足够数量的纯PNMT将 从牛肾上腺获得，以允许尝试结晶 并对其X射线晶体结构进行了测定。分子 生物实验的提出将使我们能够获得人类 肾上腺PNMT和可能的人脑PNMT的数量足以 使用更相关的人类酶和 还尝试了晶化和X射线晶体结构测定 其中的一部分。所有子项目的结果将在协同中合并 时尚导致合成一种高度有效和选择性的 PNMT的抑制剂。这种抑制剂将是一种有用的药理作用 探讨肾上腺素在中枢神经系统中作用的工具 系统，特别是有可能确定一种新的药物机制 高血压的治疗。