Different Structural Origins of the Enantioselectivity of Haloalkane Dehalogenases toward Linear β-Haloalkanes: Open-Solvated versus Occluded-Desolvated Active Sites
作者:Veronika Liskova、Veronika Stepankova、David Bednar、Jan Brezovsky、Zbynek Prokop、Radka Chaloupkova、Jiri Damborsky
DOI:10.1002/anie.201611193
日期:2017.4.18
directional interactions. Herein we describe two distinct molecular mechanisms for the enantiodiscrimination of the β‐haloalkane 2‐bromopentane by haloalkane dehalogenases. Highly enantioselective DbjA has an open, solvent‐accessible active site, whereas the engineered enzyme DhaA31 has an occluded and less solvated cavity but shows similar enantioselectivity. The enantioselectivity of DhaA31 arises from
线性β-卤代烷的酶促对映异构是困难的,因为底物的简单结构阻止了方向性相互作用。在本文中,我们描述了卤代烷脱卤酶对β-卤代烷2-溴戊烷进行对映异构化的两种不同的分子机制。高对映选择性的DbjA具有开放的,溶剂可及的活性位点,而工程化酶DhaA31具有闭塞的和较少溶剂化的腔,但显示出相似的对映选择性。DhaA31的对映选择性来自两个特定的取代作用而不是DbjA中的水合作用引起的位阻。