Characterization of xenobiotic reductase A (XenA): study of active site residues, substrate spectrum and stability
作者:Yanto Yanto、Hua-Hsiang Yu、Mélanie Hall、Andreas S. Bommarius
DOI:10.1039/c0cc02354j
日期:——
Xenobiotic reductase A (XenA) has broad catalytic activity and reduces various α,β-unsaturated and nitro compounds with moderate to excellent stereoselectivity. Single mutants C25G and C25V are able to reduce nitrobenzene, a non-active substrate for the wild type, to produce aniline. Total turnover is dominated by chemical rather than thermal instability.
Focused Directed Evolution of Pentaerythritol Tetranitrate Reductase by Using Automated Anaerobic Kinetic Screening of Site-Saturated Libraries
作者:Martyn E. Hulley、Helen S. Toogood、Anna Fryszkowska、David Mansell、Gill M. Stephens、John M. Gardiner、Nigel S. Scrutton
DOI:10.1002/cbic.201000527
日期:2010.11.22
Members of the library: Multiple site‐saturated libraries of PETN reductase (shown) were screened for improved kinetic rate against a variety of poorly reduced α,β‐unsaturated activated alkenes by using an anaerobic robotics facility. Two mutants (T26S and W102F) showed a switch in product enantiopreference with substrates (E)‐2‐phenyl‐1‐nitropropene and α‐methyl‐trans‐cinnamaldehyde, respectively
文库成员:通过使用厌氧机器人设备,筛选了多个位点饱和的 PETN 还原酶文库(如图所示),以提高对各种还原程度较差的 α,β-不饱和活化烯烃的动力学速率。两个突变体(T26S 和 W102F)分别显示了与底物 ( E )-2-苯基-1-硝基丙烯和 α-甲基-反式-肉桂醛的产物对映体偏好的转换。
Nicotinamide-Dependent Ene Reductases as Alternative Biocatalysts for the Reduction of Activated Alkenes
Four NAD(P)H-dependent non-flavin ene reductases have been investigated for their ability to reduce activatedC=Cbonds in an asymmetric fashion by using 20 structurally diverse substrates. In comparison with flavin-dependent OldYellowEnzyme homologues, a higher degree of electronic activation was required, because the best activities were obtained with enals and nitroalkenes rather than enones and
Enantio- and regioselective <i>ene</i>-reductions using F<sub>420</sub>H<sub>2</sub>-dependent enzymes
作者:Sam Mathew、Milos Trajkovic、Hemant Kumar、Quoc-Thai Nguyen、Marco W. Fraaije
DOI:10.1039/c8cc04449j
日期:——
In the past decade it has become clear that many microbes harbor enzymes that employ an unusual flavin cofactor, the F420 deazaflavin cofactor. Herein we show that F420-dependent reductases (FDRs) can successfully perform enantio-, regio- and chemoselective ene-reductions. For the first time, we have demonstrated that F420H2-driven reductases can be used as biocatalysts for the reduction of α,β-unsaturated
在过去的十年中,很明显,许多微生物都带有使用不常见的黄素辅助因子F 420去氮黄素辅助因子的酶。本文中,我们显示了依赖F 420的还原酶(FDR)可以成功地进行对映体,区域和化学选择性烯的还原。首次,我们证明了F 420 H 2驱动的还原酶可用作生物催化剂,以良好的转化率(> 99%)以及优异的区域选择性和对映体过量(> 99)还原α,β-不饱和酮和醛。 %ee)。值得注意的是,与公认的FMN依赖的旧黄色酶(OYE)相比,FDR通常显示相反的对映选择性。
Asymmetric Bioreduction of CC Bonds using Enoate Reductases OPR1, OPR3 and YqjM: Enzyme-Based Stereocontrol
Three cloned enoate reductases from the “old yellow enzyme” family of flavoproteins were investigated in the asymmetricbioreduction of activatedalkenes. 12-Oxophytodienoatereductaseisoenzymes OPR1 and OPR3 from Lycopersicon esculentum (tomato), and YqjM from Bacillus subtilis displayed a remarkably broad substrate spectrum by reducing α,β-unsaturated aldehydes, ketones, maleimides and nitroalkenes