School of Chemistry, University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK.
York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK.
Nat Chem. 2017 Oct;9(10):961-969. doi: 10.1038/nchem.2782. Epub 2017 May 29.
Reductive amination is one of the most important methods for the synthesis of chiral amines. Here we report the discovery of an NADP(H)-dependent reductive aminase from Aspergillus oryzae (AspRedAm, Uniprot code Q2TW47) that can catalyse the reductive coupling of a broad set of carbonyl compounds with a variety of primary and secondary amines with up to >98% conversion and with up to >98% enantiomeric excess. In cases where both carbonyl and amine show high reactivity, it is possible to employ a 1:1 ratio of the substrates, forming amine products with up to 94% conversion. Steady-state kinetic studies establish that the enzyme is capable of catalysing imine formation as well as reduction. Crystal structures of AspRedAm in complex with NADP(H) and also with both NADP(H) and the pharmaceutical ingredient (R)-rasagiline are reported. We also demonstrate preparative scale reductive aminations with wild-type and Q240A variant biocatalysts displaying total turnover numbers of up to 32,000 and space time yields up to 3.73 g l d.
还原胺化反应是合成手性胺的最重要方法之一。在这里，我们报道了一种来自米曲霉（AspRedAm，Uniprot 代码 Q2TW47）的依赖 NADP（H）的还原胺酶的发现，它可以催化广泛的羰基化合物与各种伯胺和仲胺的还原偶联，转化率高达>98%，对映体过量值高达>98%。在羰基和胺都具有高反应性的情况下，有可能采用 1:1 的底物比，形成转化率高达 94%的胺产物。稳态动力学研究表明，该酶能够催化亚胺形成以及还原。报道了 AspRedAm 与 NADP（H）以及与 NADP（H）和药物成分（R）-雷沙吉兰复合物的晶体结构。我们还展示了使用野生型和 Q240A 变体生物催化剂的制备规模还原胺化反应，总周转率高达 32,000 次，时空产率高达 3.73 g l d。
