Protein-engineering of an amine transaminase for the stereoselective synthesis of a pharmaceutically relevant bicyclic amine.
Protein-engineering of an amine transaminase for the stereoselective synthesis of a pharmaceutically relevant bicyclic amine.
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用于立体选择性合成药学相关双环胺的胺转氨酶的蛋白质工程。
DOI：
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发表时间：
2016
影响因子：
3.2
通讯作者：
U. Bornscheuer
中科院分区：
文献类型：
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作者：
M. Weiß;Ioannis V. Pavlidis;P. Spurr;S. Hanlon;B. Wirz;H. Iding;U. Bornscheuer
应用胺转氨酶（ATA）对前手性酮进行立体选择性胺化，是过渡金属催化不对称合成的一种环境友好且经济有吸引力的替代方案。然而，限制性底物范围通常限制了向非空间要求支架的转换。最近，我们报道了折叠 I 类 ATA 的鉴定和设计，该 ATA 能够以高产率从相应的酮前体中高度选择性地不对称合成一组手性芳香族大胺。然而，对于此处针对的特定胺合成方法的扩展，即外型异构体与内型异构体的选择性形成，这些生物催化剂需要额外的改进。所选择的底物（外-3-氨基-8-氮杂-双环[3.2.1]辛-8-基-苯基-甲酮）除了其药理学相关性之外，也是 ATA 的一个苛刻目标，因为桥接双环提供了巨大的空间挑战。结合合理设计和定向进化的蛋白质工程能够鉴定出 ATA 变体，该变体能够以 >99.5% 的选择性催化目标外型胺的特异性合成。
Application of amine transaminases (ATAs) for stereoselective amination of prochiral ketones represents an environmentally benign and economically attractive alternative to transition metal catalyzed asymmetric synthesis. However, the restrictive substrate scope has limited the conversion typically to non-sterically demanding scaffolds. Recently, we reported on the identification and design of fold class I ATAs that effect a highly selective asymmetric synthesis of a set of chiral aromatic bulky amines from the corresponding ketone precursors in high yield. However, for the specific amine synthetic approach extension targeted here, the selective formation of an exo- vs. endo-isomer, these biocatalysts required additional refinement. The chosen substrate (exo-3-amino-8-aza-bicyclo[3.2.1]oct-8-yl-phenyl-methanone), apart from its pharmacological relevance, is a demanding target for ATAs as the bridged bicyclic ring provides substantial steric challenges. Protein engineering combining rational design and directed evolution enabled the identification of an ATA variant which catalyzes the specific synthesis of the target exo-amine with >99.5% selectivity.