CHEMICAL MECHANISMS OF BIOSYNTHESIS

生物合成的化学机制

基本信息

批准号：
3269248
负责人：
RICHARD VANCE WOLFENDEN
金额：
$ 17.94万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
1980
资助国家：
美国
起止时间：
1980-07-01 至 1990-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3269248
关键词：
affinity chromatography antimetabolites chemical synthesis enzyme inhibitors enzyme mechanism enzyme substrate analog enzyme substrate complex hydropathy inosine monophosphate ligase molecular rearrangement nuclear magnetic resonance spectroscopy purine /pyrimidine metabolism purines thymidine kinase

项目摘要

This work is aimed at developing an understanding of enzyme mechanisms through the design of transition state analogs, that resemble activated intermediates in substrate transformations catalyzed by enzymes. Because transition state analogs are chemically stable and cannot collapse to form products, their affinities for enzymes persist, and they are exceptionally potent metabolic inhibitors. In addition, structural observations on their complexes with enzymes can reveal the origins of their unusual affinities for enzymes, which parallel the interactions that are responsible for the catalytic rate enhancements that enzymes bring about. Targets proposed for inhibitor design include three enzymes involved in purine biosynthesis: adenylosuccinate synthetase, inosinic acid dehydrogenase and guanylate synthetase (XMP aminase); in each of the cases there is evidence of a high-energy intermediate whose structure can in principle be imitated with one or more stable analogs that we intend to prepare. Bisubstrate analogs are to be prepared for three kinases that are active in rapidly-dividing cells: thymidine kinase, thymidylate kinase and tyrosine-specific protein kinases. In view of evidence that pyridoxal-requiring enzymes proceed through planar intermediates, a planar bisubstrate analog is to be prepared as a potential inhibitor of pyridoxamine pyruvate transaminase. Finally, experiments relating to the production and purification of new enzyme activities are proposed, using transition state analogs as templates and as eluting agents for chromatographic separation of molecules according to their catalytic turnover numbers.

这项工作旨在发展对酶机制的理解通过过渡状态类似物的设计，类似于激活由酶催化的底物转化中的中间体。因为过渡状态类似物在化学上是稳定的，无法崩溃以形成产品，它们对酶的亲和力持续存在，它们异常有效的代谢抑制剂。另外，对其的结构观察与酶的复合物可以揭示其异常亲和力的起源对于酶，与负责的相互作用平行酶带来的催化速率提高。提出的针对抑制剂设计的目标包括三种涉及的酶嘌呤生物合成：腺苷酸习惯蛋白合成酶，肌苷酸脱氢酶和鸟苷酸合成酶（XMP AMINAPE）；在每种情况下有证据表明高能中间体的结构可以我们打算用一个或多个稳定的类似物来模仿原理准备。 Bisubstrate类似物应为三种激酶准备活跃在快速分裂的细胞中：胸苷激酶，胸苷酸激酶和酪氨酸特异性蛋白激酶。鉴于证据吡ido虫重新测量酶通过平面中间体（平面）进行 Bisubstrate类似物应作为潜在的抑制剂准备吡啶毒素丙酮酸转氨酸酶。最后，与提出了新酶活性的生产和纯化，使用过渡状态类似物作为模板和洗脱剂分子的色谱分离根据其催化营业额数字。