期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
菜豆环氧水解酶归一性水解间硝基环氧苯乙烷的研究
1
作者 李闯 文正 +1 位作者 刘畅 邬敏辰 《生物技术通报》 CAS CSCD 北大核心 2020年第1期73-80,共8页
旨在研究菜豆环氧水解酶PvEH2对映归一性水解外消旋(rac-)间硝基环氧苯乙烷(mNSO)的特性,为制备光学纯(R)-间硝基苯乙二醇(mNPED)提供优良的生物催化剂。构建表达有重组PvEH2的工程菌E.coli/pveh2。以rac-mNSO为底物,借助手性色谱法分析... 旨在研究菜豆环氧水解酶PvEH2对映归一性水解外消旋(rac-)间硝基环氧苯乙烷(mNSO)的特性,为制备光学纯(R)-间硝基苯乙二醇(mNPED)提供优良的生物催化剂。构建表达有重组PvEH2的工程菌E.coli/pveh2。以rac-mNSO为底物,借助手性色谱法分析E.coli/pveh2全细胞的EH活性和区域选择性。基于有机助溶剂种类和剂量对酶活性的影响,筛选并优化缓冲液/助溶剂反应体系。结果显示,在菜豆植株中,PvEH2基因的转录水平可能受体外环境诱导因素的影响。E.coli/pveh2的EH活性为15.4 U/g,水解反应的区域选择性系数αS和βR分别为90.3%和96.4%。在经过筛选优化的含有5%(V/V)丙三醇的磷酸干细胞盐缓冲液中,最高底物浓度为40 mmol/L,是原缓冲液体系的4倍。当反应至12 h时,所得(R)-mNPED的光学纯度eep及产率分别为84.9%和90.2%。E.coli/pveh2或PvEH2在水解rac-mNSO中表现出优秀的区域选择性,在制备光学纯(R)-mNPED中具有较好的应用潜力。 展开更多
关键词 环氧水解酶 对映归一性水解 间硝基环氧苯乙烷 间硝基苯乙二醇
下载PDF
Cloning and expression of the gene encoding(R)-specific carbonyl reductase from Candida parapsilosis CCTCC M203011
2
作者 Na XU Haiyan WANG +2 位作者 Yao NIE Yan XU Rong XIAO 《Frontiers in Biology》 CSCD 2008年第1期19-25,共7页
The gene which encodes(R)-specific carbonyl reductase(rCR)from Candida parapsilosis CCTCC M203011 was cloned,sequenced and compared with genes from the GenBank.The results indicated that rCR gene was 1011 bp,encoding ... The gene which encodes(R)-specific carbonyl reductase(rCR)from Candida parapsilosis CCTCC M203011 was cloned,sequenced and compared with genes from the GenBank.The results indicated that rCR gene was 1011 bp,encoding a protein of 336 amino acids with a molecular weight of 35.9 kDa,and its nucleotide sequence showed 99%similarity to those of other members of the alcohol dehydrogenase superfamily.The rCR gene could express in recombinant strain Escherichia coli JM109,and the expression plasmid could produce(R)-1-pheny-1,2-ethanediol(100%e.e.,80.14%yield)from b-hydroxyacetophenone without any additive to regenerate NAD+from NADH. 展开更多
关键词 carbonyl reductase EXPRESSION asymmetric reduction (R)-1-phenyl-1 2-ethanediol
原文传递
Purification and characterization of a novel carbonyl reductase with high stereo-selectivity
3
作者 YANG Ming XU Yan +1 位作者 MU Xiaoqing XIAO Rong 《Frontiers of Chemical Science and Engineering》 SCIE EI CSCD 2007年第4期404-410,共7页
A novel NADPH-dependent carbonyl reductase was separated from Candida parapsilosis CCTCC 203011.The enzyme gave a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE),which was purified t... A novel NADPH-dependent carbonyl reductase was separated from Candida parapsilosis CCTCC 203011.The enzyme gave a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE),which was purified through ammonium sulfate,Diethylamino Ethanol(DEAE)sepharose Fast flow(FF),phenyl-sepharose FF and blue sepharose FF chromato graphy from cell-free extract.The molecular mass of the enzyme was about 30 kDa.The optimum pH and temperature for reduction were 4.5℃ and 35℃,respectively.The Cu2+had strong restrictive effect on enzyme activity.In addition,the carbonyl reductase was an enzyme with high substrate specificity and stereo-selectivity,and showed high asymmetric reduction activity towards a-hydroxyacetophenone and ethyl 4-chloro acetoacetate.For the asymmetric reduction of a-hydroxyacetophenone and ethyl 4-chloro acetoacetate,(S)-1-phenyl-1,2-ethanediol and(R)-ethyl 4-chloro-3-hydroxybutanoate were produced by the purified enzyme,with the 100% and 94.3%e.e.value,respec-tively.Therefore,the enzyme could be one of the effective biocatalysts for asymmetric synthesis of chiral alcohols.The amino acid sequences of one peptide from the purified enzyme were analyzed by LC-MASS-MASS,and the car-bonyl reductase showed some identity to the hypothetical protein CaO19.10414 reported. 展开更多
关键词 BIOCATALYSIS carbonyl reductase purification (S)-1-phenyl-1 2-ethanediol (R)-ethyl 4-chloro-3-hydroxybutanoate
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部