Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
Present address: Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
Angew Chem Int Ed Engl. 2021 Nov 2;60(45):24059-24063. doi: 10.1002/anie.202110719. Epub 2021 Oct 5.
Cyclopropane rings are an important structural motif frequently found in many natural products and pharmaceuticals. Commonly, biocatalytic methodologies for the asymmetric synthesis of cyclopropanes rely on repurposed or artificial heme enzymes. Here, we engineered an unusual cofactor-independent cyclopropanation enzyme based on a promiscuous tautomerase for the enantioselective synthesis of various cyclopropanes via the nucleophilic addition of diethyl 2-chloromalonate to α,β-unsaturated aldehydes. The engineered enzyme promotes formation of the two new carbon-carbon bonds with excellent stereocontrol over both stereocenters, affording the desired cyclopropanes with high diastereo- and enantiopurity (d.r. up to 25:1; e.r. up to 99:1). Our results highlight the usefulness of promiscuous enzymes for expanding the biocatalytic repertoire for non-natural reactions.
环丙烷环是许多天然产物和药物中常见的重要结构基序。通常，用于不对称合成环丙烷的生物催化方法依赖于重新利用或人工血红素酶。在这里，我们基于一种混杂的互变异构酶，设计了一种不常见的辅酶独立环丙烷化酶，用于通过二乙基 2-氯丙二酸酯对α，β-不饱和醛的亲核加成，对各种环丙烷进行对映选择性合成。该工程酶促进两个新的碳-碳键的形成，对两个立体中心具有极好的立体控制，以高非对映体和对映体纯度（d.r. 高达 25:1；e.r. 高达 99:1）提供所需的环丙烷。我们的结果强调了混杂酶在扩展非天然反应的生物催化谱方面的有用性。
