NMR study of ¹³C-kinetic isotope effects at ¹³C natural abundance to characterize oxidations and an enzyme-catalyzed reduction

详细信息    查看全文

• 作者：Lothar Brecker ; Marion F. Kö ; gl ; Catrin E. Tyl ; Regina Kratzer and Bernd Nidetzky
• 关键词：¹³C NMR ; KIE ; Oxidation ; Reduction ; Xylose reductase
• 刊名：Tetrahedron Letters
• 出版年：2006
• 出版时间：6 June 2006
• 年：2006
• 卷：47
• 期：24
• 页码：4045-4049
• 全文大小：147 K

文摘

¹³C-kinetic isotope effects (KIEs) of four cinnamyl alcohol oxidations and a xylose reductase-catalyzed cinnamyl aldehyde reduction have been determined by ¹³C NMR using competition reactions with reactants at natural ¹³C-abundance. Differences in KIEs among oxidations indicate dissimilarities between the respective hydrogen transfers. Their mechanistic implications are discussed. A low primary KIE of the enzymatic reduction is consistent with a kinetically complex mechanism in which steps other than the chemical step of hydride transfer from NADH are slow.