Alcohol Dehydrogenase (ADH) enzymes catalyse the reversible reduction of prochiral ketones to the corresponding alcohols. These enzymes present two differently shaped active site pockets, which dictate their substrate scope and selectivity. In this study, we computationally evaluate the effect of two commonly reported active site mutations (I86A, and W110T) on a secondary alcohol dehydrogenase from Thermoanaerobacter brockii (TbSADH) through Molecular Dynamics simulations. Our results indicate that the introduced mutations induce dramatic changes on the shape of the active site, but most importantly they impact the substrate-enzyme interactions. We demonstrate that the combination of Molecular Dynamics simulations with the tools POVME and NCIplot correspond to a powerful strategy for rationalising and engineering the stereoselectivity of ADH variants

A.R.R. thanks the Generalitat de Catalunya for PhD fellowship (2015-FI-B-00165), M.A.M.S is grateful to the Spanish MINECO for PhD fellowship (BES-2015-074964). S.O. thanks the Spanish MINECO for project CTQ2014-59212-P, Ramón y Cajal contract (RYC-2014-16846), the European Community for CIG project (PCIG14-GA-2013-630978), and the funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (ERC-2015-StG-679001)