STEREOCHEMISTRY OF ENZYME REACTIONS

在我们对酶的立体化学的继续研究中 反应主要集中在各种反应的立体过程上 关于一碳代谢和脱氧己糖的形成机制， 仍有一些努力用于完成正在进行的关于 磷酸吡哆醛酶和色氨酸异戊二烯基化的研究 克莱维塞斯。关于单碳代谢的研究将检验 DNA甲基化、蛋氨酸生物合成、 亚甲二氧基和黄连素桥的形成 生物碱的生物合成，以及硫代霉素所涉及的双甲基化 生物合成。在关于脱氧己糖形成的工作中，我们将研究 立体化学和机械方面的形成 吡哆胺从CDP-4-酮-6-脱氧葡萄糖合成CDP-3，6-双脱氧葡萄糖 沙门氏菌的磷酸依赖酶。探索性研究也将 链霉菌生物合成2，6-二脱氧己糖的研究 关于硫胺素焦磷酸催化酶的立体化学 反应。

In the continuation of our studies on the stereochemistry of enzyme reactions the major focus will be on the steric course of various reactions of one-carbon metabolism and on the mechanism of deoxyhexose formation, with some effort still devoted to the completion of ongoing studies on pyridoxal phosphate enzymes and on the isoprenylation of tryptophan in Claviceps. The studies on one-carbon metabolism will examine stereochemical aspects of DNA methylation, methionine biosynthesis, the formation of the methylenedioxy function and the berberine bridge in alkaloid biosynthesis, and the double methylation involved in thienamycin biosynthesis. In the work on deoxyhexose formation we will study stereochemical and mechanistic aspects of the formation of CDP-3,6-dideoxyglucose from CDP-4-keto-6-deoxyglucose by a pyridoxamine phosphate-dependent enzyme from Salmonella. Exploratory studies will also be carried out on the biosynthesis of 2,6-dideoxyhexoses in Streptomyces and on the stereochemistry of thiamine pyrophosphate-catalyzed enzyme reactions.