Stereochemical Outcome at Four Stereogenic Centers during Conversion of Prephenate to Tetrahydrotyrosine by BacABGF in the Bacilysin Pathway
作者:Jared B. Parker、Christopher T. Walsh
DOI:10.1021/bi3006362
日期:2012.7.17
NADH-utilizing BacG then catalyzes a conjugate reduction, adding a pro-S hydride equivalent to C4 to yield tetrahydrohydroxyphenylpyruvate (H4HPP), a transamination away (via BacF) from 2S-H4Tyr. Incubations of the pathway enzymes in D2O yield deuterium incorporation at C8 from BacA and then C9 from BacB action. By 1H NMR analysis of samples of H4Tyr, the stereochemistry at C4, C8, and C9 can be assigned
杆菌肽抗生素途径的前四种酶 BacABGF在通往二肽抗生素的抗辣椒素弹头的途中将 prephenate转化为四氢酪氨酸(H 4 Tyr) 非对映异构体。BACB取巴卡产物内环-Δ 4,Δ 8 -7 - [R -dihydrohydroxyphenylpyruvate(烯ħ 2 HPP),并产生3的混合物ë -和3 Ž所述的α-烯烃环外-Δ 3,Δ 5 -dihydrohydroxyphenylpyruvate(前-H 2 HPP)。然后利用 NADH 的 BacG 催化共轭还原,添加一个 pro-S氢化物相当于 C 4以产生四氢羟基苯基丙酮酸(H 4 HPP),从 2 S -H 4 Tyr转氨基(通过 BacF)。途径酶在 D 2 O 中的培养产生了来自 BacA 的C 8处的氘掺入,然后来自 BacB 作用的C 9掺入。通过H 4 Tyr样品的1 H NMR 分析,可以确定C 4、C 8和