NEUROPEPTIDES--APPROACHES TO ALPHA-AMIDATION EFFECTORS

神经肽--α-酰胺化效应子的研究方法

• 批准号: 3298182
• 负责人: SHELDON W MAY
• 金额: $ 21.15万
• 依托单位: GEORGIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-02-01 至 1996-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3298182
• 关键词: amides; catecholamines; chemical stability; chromaffin cells; enzyme inhibitors; enzyme substrate; lyase; neuroeffector; neuropeptides; oxygenases; tissue /cell culture

Neuropeptides, now recognized to be vitally involved in many central and peripheral functions, are known to be generated from larger precursors via a variety of postranslational modifications. In particular, carboxyl terminus alpha-amidation is a key structural feature in the biological activity (and probably in regulation and resistance toward C-exopeptidases) of many neurohormones, with ca. 50% of known peptide hormones being amidated at their C-terminii. Although both the enzymology and biochemistry of amidation have been under active investigation for some time, only within the last two years has it become clear that amidation is actually a two step process. The enzyme peptidylglycine alpha-amidating monooxygenase (PAM) catalyzes formation of the alpha-hydroxyglycine derivative of the glycine extended substrate. Our laboratory recently isolated a novel enzyme from neurointermediate pituitary which we have named peptidylamidoglycolate lyase (PGL; see attached letter documenting consent of the Chairman of the Enzyme Nomenclature Commission of the IUB to this name). We demonstrated that PGL catalyzes the second step in neuropeptide amidation -- dealkylation of alpha-hydroxyglycine derivatives to produce the final amide product. In addition, our laboratory has also demonstrated the presence of both PAM and PGL in chromaffin granules, and we have developed the first small molecule substrates as well as new sensitive assays for the enzymes. In view of the emerging recognition of the crucial neurochemical role of alpha-amidation, we propose to initiate a new research program focusing on this process. Our goals are to explore the regulation of neuropeptide amidation and its relationship to catecholamine processing in chromaffin cells, to characterize amidating enzymes from various sources, and to design and characterize novel classes of inhibitors and mechanism-based effectors for neuropeptide amidation.

神经肽，现在被认为与许多中枢和神经系统密切相关 外围功能，已知是由较大的前体通过 各种翻译后修饰。 特别是羧基 末端α-酰胺化是生物中的一个关键结构特征 活性（可能在对 C-外肽酶的调节和抵抗中） 许多神经激素，大约。 50% 的已知肽激素是 在其 C 末端酰胺化。 尽管酶学和 酰胺化的生物化学已被一些人积极研究 时间，直到最近两年才清楚地表明酰胺化是 实际上是一个两步过程。 肽基甘氨酸α-酰胺化酶 单加氧酶 (PAM) 催化 α-羟基甘氨酸的形成 甘氨酸延伸底物的衍生物。 我们实验室最近 从神经中间垂体中分离出一种新型酶 命名为肽酰氨基乙醇酸裂解酶（PGL；参见随附的信件记录 IUB 酶命名委员会主席同意 这个名字）。 我们证明了 PGL 催化了第二步 神经肽酰胺化——α-羟基甘氨酸衍生物的脱烷基化 生产最终的酰胺产品。 此外，我们实验室还 证明嗜铬颗粒中同时存在 PAM 和 PGL，并且 我们开发了第一个小分子底物以及新的 酶的灵敏测定。 鉴于人们日益认识到 α-酰胺化的关键神经化学作用，我们建议启动 一个专注于这一过程的新研究计划。 我们的目标是探索 神经肽酰胺化的调控及其与 嗜铬细胞中的儿茶酚胺加工，以表征酰胺化 来自各种来源的酶，并设计和表征新类别 神经肽酰胺化的抑制剂和基于机制的效应器。