Purification and characterization of a novel alcohol dehydrogenase from Leifsonia sp strain S749:: a promising biocatalyst for an asymmetric hydrogen transfer bioreduction
Purification and characterization of a novel alcohol dehydrogenase from Leifsonia sp strain S749:: a promising biocatalyst for an asymmetric hydrogen transfer bioreduction
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DOI：
10.1128/aem.71.7.3633-3641.2005
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发表时间：
2005-07-01
影响因子：
4.4
通讯作者：
Itoh, N
中科院分区：
文献类型：
--
作者：
Inoue, K;Makino, Y;Itoh, N
为了找到可以将苯基三氟甲基酮（PTK）还原为（S）-1-苯基三氟乙醇[（S）-PTE]的微生物，苯乙烯同化细菌（ca. 900株）进行了筛选。我们发现Leifsonia sp.菌株S749是在2-丙醇作为氢供体存在下将PTK转化为（S）-PTE的最合适的菌株。将与该反应对应的酶纯化、表征并命名为Leifsonia醇脱氢酶（LSADH）。纯化的酶具有110，000的分子量，并且由四个相同的亚基（分子量，26，000）组成。LSADH需要NADH作为辅因子，对NADPH几乎没有活性，并还原多种醛和酮。LSADH催化具有高对映体过量（e.e.）的某些酮的对映选择性还原：PTK转化为（S）-PTE（>99% e.e.），苯乙酮转化为（R）-1-苯基乙醇（99% e.e.），和2-庚酮转化为（R）-2-庚醇（> 99% e.e.）在2-丙醇的存在下，没有额外的NADH再生系统。因此，它将是一种有用的生物催化剂。
To find microorganisms that could reduce phenyl trifluoromethyl ketone (PTK) to (S)-1-phenyltrifluoroethanol [(S)-PTE], styrene-assimilating bacteria (ca. 900 strains) isolated from soil samples were screened. We found that Leifsonia sp. strain S749 was the most suitable strain for the conversion of PTK to (S)-PTE in the presence of 2-propanol as a hydrogen donor. The enzyme corresponding to the reaction was purified homogeneity, characterized and designated Leifsonia alcohol dehydrogenase (LSADH). The purified enzyme had a molecular weight of 110,000 and was composed of four identical subunits (molecular weight, 26,000). LSADH required NADH as a cofactor, showed little activity with NADPH, and reduced a wide variety of aldehydes and ketones. LSADH catalyzed the enantioselective reduction of some ketones with high enantiomeric excesses (e.e.): PTK to (S)-PTE (>99% e.e.), acetophenone to (R)-1-phenylethanol (99% e.e.), and 2-heptanone to (R)-2-heptanol (>99% e.e.) in the presence of 2-propanol without an additional NADH regeneration system. Therefore, it would be a useful biocatalyst.