Epoxide hydrolase activity of Streptomyces strains.
Epoxide hydrolase activity of Streptomyces strains.
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DOI：
10.1016/s0168-1656(99)00225-4
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发表时间：
2000-02
影响因子：
4.1
通讯作者：
Frank Zocher;M. Enzelberger;U. Bornscheuer;B. Hauer;W. Wohlleben;R. Schmid
中科院分区：
文献类型：
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作者：
Frank Zocher;M. Enzelberger;U. Bornscheuer;B. Hauer;W. Wohlleben;R. Schmid
环氧化物水解酶的发现在链霉菌属物种菌株收集。筛选在96孔微量滴定板中进行，使用改进的4-（p-硝基苄基）吡啶测定，用氧化苯乙烯、1，2-环氧-己烷或3-苯基乙基缩水甘油酸酯（3-PEG）作为底物。在120个菌株中，S. Aestheticus Tü4，S. arenae Tü 495和S.草莓Tü 27具有环氧化物水解酶活性。这些菌株进行了进一步研究，通过进行实验室规模的生物转化利用氧化苯乙烯，1，2-环氧己烷和3-PEG，随后采用手性气相色谱定量分析。用来自S.在存在10%（v/v）DMSO的情况下，对嗜水气单胞菌Tü 4进行纯化。然而，对映体选择性仅在5%（v/v）丙酮存在下才令人满意（E=31），这允许在24小时后以55%的转化率分离光学纯的未水解的（R）-氧化苯乙烯（99%对映体过量（ee））和（S）-苯基-1，2-乙二醇（72%ee）。3-PEG的拆分虽然反应速率较高，但对映选择性略低。链球菌fragalus Tü 27和S. arenae Tü 495对氧化苯乙烯的对映选择性仅为E=3-4。
The discovery of epoxide hydrolases within a Streptomyces sp. strain collection is described. Screening was performed in 96 well microtiter plates using a modified 4-(p-nitrobenzyl)pyridine assay with styrene oxide, 1,2-epoxy-hexane or 3-phenyl ethylglycidate (3-PEG) as substrates. Out of 120 strains investigated, S. antibioticus Tü4, S. arenae Tü495 and S. fradiae Tü27 exhibited epoxide hydrolase activity. These strains were further investigated by performing laboratory-scale biotransformations utilizing styrene oxide, 1,2-epoxy-hexane and 3-PEG followed by subsequent quantitative analysis employing chiral gas chromatography. The highest conversions were achieved with whole cells from S. antibioticus Tü4 in the presence of 10% (v/v) DMSO. However, enantioselectivity was only satisfying (E=31) in the presence of 5% (v/v) acetone, which allowed isolation of optically pure non-hydrolyzed (R)-styrene oxide (99% enantiomeric excess (ee)) and (S)-phenyl-1,2-ethandiol (72% ee) at 55% conversion after 24 h. The resolution of 3-PEG proceeded with slightly lower enantioselectivity albeit higher reaction rates. With S. fradiae Tü27 and S. arenae Tü495 enantioselectivity towards styrene oxide was only E=3–4.