基于非天然叔胺辅因子的人工酶创制及应用

Enzymatic MBH reaction catalyzed by an artificial enzyme designed with the introduction of an unnatural tertiary amine cofactor

摘要:

生物酶元件作为合成生物学系统的芯片对生物制造产业有着至关重要的作用。发展多样性新功能酶元件可为合成生物学系统提供丰富的工具盒并助力其发展。本研究报道了一种基于非天然辅因子的新型人工酶构建方法，通过非天然氨基酸结合点击化学策略将4-二甲氨基吡啶(4-dimethylaminopyridine,DMAP)辅因子通过共价键引入至优选蛋白骨架中，成功构建了一种以叔胺辅因子为催化中心的新型人工酶。该人工酶成功实现了一例环状烯酮与对硝基苯甲醛之间发生的非天然不对称Morita-Baylis-Hillman (MBH)反应，转化率高达90%、对映选择性(e.e.)为38%。本研究不仅为新型人工酶的设计提供了一种有效策略，而且为发展酶催化非天然MBH反应建立了理论基础。

关键词:遗传密码子扩展;人工酶;MBH反应;生物催化;不对称催化

Abstract:

As the chip of synthetic biology, enzymes play a vital role in the bio-manufacturing industry. The development of diverse functional enzymes can provide a rich toolbox for the development of synthetic biology. This article reports the construction of an artificial enzyme with the introduction of a non-natural cofactor. By introducing the 4-dimethylaminopyridine (DMAP) cofactor into the optimal protein skeleton via covalent bonds based on a click-chemistry strategy, we successfully constructed a novel artificial enzyme with the DMAP cofactor as the catalytic center. The artificial enzyme successfully catalyzed an unnatural asymmetric Morita-Baylis- Hillman (MBH) reaction between cycloketenone and p-nitrobenzaldehyde, with a conversion rate of 90% and enantioselectivity (e.e.) of 38%. This study not only provides an effective strategy for the design of new artificial enzymes but also establishes a theoretical basis for the development of unnatural biocatalytic MBH reactions.

Key words:genetic codon expansion;artificial enzyme;Morita-Baylis-Hillman (MBH) reaction;biocatalysis;asymmetric catalysis