The acarbose-biosynthetic enzyme AcbO from <i>Actinoplanes</i>
sp. SE 50/110 is a 2-<i>epi</i>
-5-<i>epi</i>
-valiolone-7-phosphate 2-epimerase
作者:Chang-Sheng Zhang、Michael Podeschwa、Hans-Josef Altenbach、Wolfgang Piepersberg、Udo F Wehmeier
DOI:10.1016/s0014-5793(03)00221-7
日期:2003.4.10
The C7‐cyclitol 2‐epi‐5‐epi‐valiolone is the first precursor of the cyclitol moiety of the α‐glucosidase inhibitor acarbose in Actinoplanes sp. SE50. The 2‐epi‐5‐epi‐valiolone becomes phosphorylated at C7 by the ATP dependent kinase AcbM prior to the next modifications. Preliminary data gave evidences that the AcbO protein could catalyse the first modification step of 2‐epi‐5‐epi‐valiolone‐7‐phosphate
C7-环醇 2-epi-5-epi-valiolone 是放线菌中 α-葡萄糖苷酶抑制剂阿卡波糖的环醇部分的第一个前体。SE50。在下一次修饰之前,2-epi-5-epi-valiolone 在 C7 处被 ATP 依赖性激酶 AcbM 磷酸化。初步数据表明,AcbO 蛋白可以催化 2-epi-5-epi-valiolone-7-磷酸盐的第一个修饰步骤。因此,AcbO 蛋白(其编码基因也是 acbKMLNOC 操纵子的一部分)被过度生产和纯化。事实上,纯化的蛋白质催化了 2-epi-5-epi-valiolone-7-磷酸盐的 2-差向异构化。纯化反应产物的化学结构经核磁共振波谱证实为 5-epi-valiolone-7-磷酸盐。