38 イソプレノイド生合成における鎖延長機構 : "stepwise"機構によるE-プレニル鎖々延長(ポスター発表の部)

概要

論文の詳細を見る
Stereochemistry and mechanism in the chain elongation of E-prenyl chain in the biosynthesis of geranyl diphosphate (GPP) and farnesyl diphosphate (FPP) were investigated. (i) A chain-length-specific GPP synthase was detected in leaves of Pelargonium roseum; GPP synthase was separated from FPP synthase by hydrophobic chromatography on Butyl-Toyopearl. This separation demonstrates that there are two specific synthase, GPP synthase and FPP synthase, in higher plant. Biosynthesis of GPP with the GPP synthase was found to involve the addition of dimethylallyl diphosphate to the double bond of isopentenyl diphosphate (IPP) from its si-si face and then the syn elimination of the C(2)-H of IPP. (ii) Evidence for the generation of geranyl cation intermediate during the enzymatic condensation of GPP to IPP with the FPP synthase from pumpkin was given by monitoring the enzymatic reaction by means of ^<13>C NMR measurements. This is direct evidence to approve the generation of carbocation intermediate during the enzymatic prenylation, and supports the involvement of the "stepwise" mechanism in the prenylation.
天然有機化合物討論会の論文
1990-09-25