Transesterifications and Peracid-Assisted Oxidations in Aqueous Media Catalyzed by Mycobacterium smegmatis Acyl Transferase

Hydrolases catalyze synthetic reactions in nonaqueous media, whereas they perform hydrolysis under aqueous solutions. An acyl transferase from Mycobacterium smegmatis (MsAcT) is able to catalyze synthetic reactions in buffer because of its highly hydrophobic active site, which enables efficient transesterification reactions even at 99.9% v/v buffer solution. This unique feature of MsAcT among hydrolases may open new opportunities to conduct synthetic (bio)catalysis in aqueous media. With these goals in mind, this paper explores some evidence of such potential: MsAcT can perform enantioselective transesterifications (e.g., (S)-2-octanol), which could be combined with other aqueous multistep (asymmetric) reactions; 5-hydroxymethylfurfural (HMF) can be esterified to produce more hydrophobic and easily extractable HMF esters (e.g., for downstream processing or wastewater treatment); and upon addition of dilute H2O2, MsAcT works efficiently as a perhydrolase to form insitu peracidsin bulk waterthat can be used for oxidations (e.g., furfural to furoic acid oxidation). Overall, these and many other new applications can be envisaged by using MsAcT in aqueous solutions.