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Efficient production of (S)-1-phenyl-1,2-ethanediol using xylan as co-substrate by a coupled multi-enzyme Escherichia coli system.
Microbial Cell Factories ( IF 4.3 ) Pub Date : 2020-04-07 , DOI: 10.1186/s12934-020-01344-x
Junchao Rao 1 , Rongzhen Zhang 1, 2 , Guanyu Xu 3 , Lihong Li 1 , Yan Xu 1
Affiliation  

BACKGROUND (S)-1-phenyl-1,2-ethanediol is an important chiral intermediate in the synthesis of liquid crystals and chiral biphosphines. (S)-carbonyl reductase II from Candida parapsilosis catalyzes the conversion of 2-hydroxyacetophenone to (S)-1-phenyl-1,2-ethanediol with NADPH as a cofactor. Glucose dehydrogenase with a Ala258Phe mutation is able to catalyze the oxidation of xylose with concomitant reduction of NADP+ to NADPH, while endo-β-1,4-xylanase 2 catalyzes the conversion of xylan to xylose. In the present work, the Ala258Phe glucose dehydrogenase mutant and endo-β-1,4-xylanase 2 were introduced into the (S)-carbonyl reductase II-mediated chiral pathway to strengthen cofactor regeneration by using xylan as a naturally abundant co-substrate. RESULTS We constructed several coupled multi-enzyme systems by introducing (S)-carbonyl reductase II, the A258F glucose dehydrogenase mutant and endo-β-1,4-xylanase 2 into Escherichia coli. Different strains were produced by altering the location of the encoding genes on the plasmid. Only recombinant E. coli/pET-G-S-2 expressed all three enzymes, and this strain produced (S)-1-phenyl-1,2-ethanediol from 2-hydroxyacetophenone as a substrate and xylan as a co-substrate. The optical purity was 100% and the yield was 98.3% (6 g/L 2-HAP) under optimal conditions of 35 °C, pH 6.5 and a 2:1 substrate-co-substrate ratio. The introduction of A258F glucose dehydrogenase and endo-β-1,4-xylanase 2 into the (S)-carbonyl reductase II-mediated chiral pathway caused a 54.6% increase in yield, and simultaneously reduced the reaction time from 48 to 28 h. CONCLUSIONS This study demonstrates efficient chiral synthesis using a pentose as a co-substrate to enhance cofactor regeneration. This provides a new approach for enantiomeric catalysis through the inclusion of naturally abundant materials.

中文翻译:

使用木聚糖作为共底物,通过偶联的多酶大肠杆菌系统有效生产(S)-1-苯基-1,2-乙二醇。

背景技术(S)-1-苯基-1,2-乙二醇是液晶和手性双膦的合成中的重要手性中间体。副产假丝酵母的(S)-羰基还原酶II以NADPH为辅因子催化2-羟基苯乙酮向(S)-1-苯基-1,2-乙二醇的转化。具有Ala258Phe突变的葡萄糖脱氢酶能够催化木糖的氧化,同时将NADP +还原为NADPH,而内切β-1,4-木聚糖酶2则催化木聚糖转化为木糖。在目前的工作中,将Ala258Phe葡萄糖脱氢酶突变体和内-β-1,4-木聚糖酶2引入(S)-羰基还原酶II介导的手性途径,以利用木聚糖作为天然丰富的共底物来增强辅因子的再生。 。结果我们通过将(S)-羰基还原酶II,A258F葡萄糖脱氢酶突变体和内切β-1,4-木聚糖酶2引入大肠杆菌中,构建了几种偶联的多酶系统。通过改变编码基因在质粒上的位置产生了不同的菌株。仅重组大肠杆菌/ pET-GS-2表达了所有三种酶,该菌株从以2-羟基苯乙酮为底物和以木聚糖为共底物的(S)-1-苯基-1,2-乙二醇生成。在最佳温度35°C,pH 6.5和2:1底物与底物之间的比率下,光学纯度为100%,产率为98.3%(6 g / L 2-HAP)。将A258F葡萄糖脱氢酶和内切β-1,4-木聚糖酶2引入(S)-羰基还原酶II介导的手性途径可提高收率54.6%,同时将反应时间从48 h缩短至28 h。结论本研究证明了使用戊糖作为辅助底物以增强辅因子再生的有效手性合成。通过提供天然丰富的物质,这为对映体催化提供了一种新方法。
更新日期:2020-04-22
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