ENZYMES OF THE META-FISSION PATHWAY

这项研究的长期目标是彻底定义 每种酶在后裂变中的精确化学机制 路径。对这些酶的研究具有相当高的智能性 以及实际影响。这些研究应该澄清 机制和立体化学在生物进化中的作用 分解代谢途径，因为它们适应特定的底物。在……里面 此外，芳香族化合物的生物降解代表了一种 当前有毒废物污染问题的潜在解决方案。 在这一融资期间，我们将重点关注三个关键问题 该途径的酶：4-草酰基转移酶，4-草酰基转移酶 草酸脱羧酶和乙烯基丙酮酸水合酶。这些 酶代表了一种看似普通的 用于通过变裂变降解化合物的化学策略 路线。这些探索性研究将作为 今后详细的机理研究和初步的 2-HOD水解酶支链的研究。 在这笔资金中，我们的具体目标按优先顺序列出 期限为： (1)对建议的中间体的明确标识 变裂变途径的4-草酰基碳酸盐分支。 (2)非酶化学的表征 4-草酸根支链的中间体。 (3)4-草酰基碳酸酯的立体专一性测定 互变删除酶。 (4)乙烯基丙酮酸水合酶作用的测定：是这样吗？ 水合酶还是水解酶？ (5)4-的立体化学过程的测定 草酸脱羧酶。 这些基础研究应该作为遗传学的基础 操纵微生物以满足特定的解毒作用 需要。此外，变裂变途径中的酶出现了 成为新型降解剂细菌构建的典范 小路。这些研究将为研究更多 在其他地方发现的变质裂变途径的复杂变异 有机体。最后，这些研究将增加对 一些基本且耐人寻味的酶过程。

The long term goal of this research is to thoroughly define the precise chemical mechanisms of each enzyme in the meta-fission pathway. Studies of these enzymes have considerable intellectual as well as practical implications. These studies should elucidate the role of mechanism and stereochemistry in the evolution of catabolic pathways as they adapt to specific substrates. In addition, biodegradation of aromatic compounds represent one potential solution to incumbent problem of toxic waste pollution. During this funding period we will focus our efforts on three key enzymes c,f this pathway: 4-oxalocrotonate tautornerase, 4- oxalocrotonate decarboxylase, and vinylpyruvate hydratase. These enzymes represent the essence of what appears to be a common chemical strategy used to degrade compounds by the meta-fission route. These exploratory studies will serve as a foundation for subsequent future detailed mechanistic studies and preliminary studies of the 2-HOD hydrolase branch. Our specific aims, listed in order of priority, during this funding period will be: (1) Unequivocal identification of the proposed intermediates of the 4-oxalocrotonate branch of the meta-fission pathway. (2) Characterization of the non-enzymatic chemistry of the intermediates of the 4-oxalocrotonate branch. (3) Determination of the stereospecificity of 4-oxalocrotonate tautomerase. (4) Determination of the role of vinylpyruvate hydratase: is it a hydratase or hydrolase? (5) Determination of the stereochemical course of the 4- oxalocrotonate decarboxylase. These basic studies should serve as a foundation for genetic manipulation of microorganisms to meet specific detoxification needs. Furthermore, the enzymes of the meta-fission pathway appear to be the model for bacterial construction of novel degradative pathways. These studies will set the stage for study of the more complex variations of the meta-fission pathway found in other organisms. Finally, these studies will increase knowledge about some basic and intriguing enzymological processes.