Chiral heterocyclic compounds are needed for important medicinal applications. We report an in silico strategy for the biocatalytic synthesis of chiral N- and O-heterocycles via Baldwin cyclization modes of hydroxy- and amino-substituted epoxides and oxetanes using the limonene epoxide hydrolase from Rhodococcus erythropolis. This enzyme normally catalyzes hydrolysis with formation of vicinal diols. Firstly, the required shutdown of the undesired natural water-mediated ring-opening is achieved by rational mutagenesis of the active site. In silico enzyme design is then continued with generation of the improved mutants. These variants prove to be versatile catalysts for preparing chiral N- and O-heterocycles with up to 99% conversion, and enantiomeric ratios up to 99:1. Crystal structural data and computational modeling reveal that Baldwin-type cyclizations, catalyzed by the reprogrammed enzyme, are enabled by reshaping the active-site environment that directs the distal RHN and HO-substituents to be intramolecular nucleophiles.

重要的医学应用需要手性杂环化合物。我们报告了一种生物催化合成手性N - 和O - 杂环化合物的计算机策略，通过 Baldwin 环化模式，使用来自Rhodococcus erythropolis的柠檬烯环氧化物水解酶，羟基和氨基取代的环氧化物和氧杂环丁烷。这种酶通常催化水解形成邻位二醇。首先，通过活性位点的合理诱变实现所需的关闭不需要的天然水介导的开环。然后继续进行计算机酶设计，产生改进的突变体。这些变体被证明是用于制备手性N - 和O的多功能催化剂- 杂环化合物，转化率高达 99%，对映体比高达 99:1。晶体结构数据和计算模型表明，由重新编程的酶催化的 Baldwin 型环化是通过重塑活性位点环境来实现的，该活性位点环境将远端 RHN 和 H2O 取代基引导为分子内亲核试剂。