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A one‐pot deracemization strategy for α‐chiral amines is reported involving an enantioselective deamination to the corresponding ketone followed by a stereoselective amination by enantiocomplementary biocatalysts. Notably, this cascade employing a ω‐transaminase and amine dehydrogenase enabled the access to both (R)‐and (S)‐amine products, just by controlling the directions of the reactions catalyzed by them. A wide range of (R)‐and (S)‐amines was obtained with excellent conversions (>80 %) and enantiomeric excess (>99 % ee). Finally, preparative scale syntheses led to obtain enantiopure (R)‐ and (S)‐13 with the isolated yields of 53 and 75 %, respectively. Make a choice, make it right: Novel one‐pot deracemization cascade, employing amine dehydrogenase and ω‐transaminase, is reported for the synthesis of enantiopure amines with excellent conversions [ABSTRACT FROM AUTHOR]

A recyclable glutamate amine donor system employing transaminase (TA), glutamate dehydrogenase (GluDH) and mutant formate dehydrogenase (FDHm) was developed, wherein amine donor Glu was regenerated using GluDH and thereby circumvented the inhibition of TA by α‐ketoglutarate. Various enantiopure β‐, γ‐amino acids, and amines were successfully synthesized with high conversions and excellent enantiomeric excess using this system. Donate amines: A recyclable glutamate amine donor system employing transaminase (TA), glutamate dehydrogenase (GluDH) and mutant formate dehydrogenase (FDHm) was developed for the synthesis of enantiopure β‐, and γ‐amino acids [ABSTRACT FROM AUTHOR]

Optically pure amines, β-amino acids and γ-amino acids are the valuable precursors to produce biologically active compounds. The ω-TAs are the class of enzymes which are widely used to produce such compounds. In this work (S)-ω-transaminase from the thermophilic eubacterium Sphaerobacter thermophilus (St-TA) was fused with Elastin-like polypeptides (ELPs) through the cloning process and expressed in E. coli cells. The characterization of this fusion complex was performed with respect to thermostability and effect of DMSO. Where in case of St-TA-ELP-V60, major difference in the transition temperature (Tt) was observed, wherein a Tt of 38 and 70°C was observed at the increasing concentration of DMSO from 5 to 25% (v/v). Interestingly, these fusion proteins the activity was preserved even after the aggregation of fusion complex at Tt. The substrate specificity and product inhibition analysis showed that ω-TA-ELPs had comparable results as that of wild type ω-TA. Moreover, the fused ω-TA could be efficiently reused for up to 20 batches of transamination reaction. Furthermore, the applicability of the fusion protein for the production of a sitagliptin precursor (R)-3-amino-4-(2,4,5-triflurophenyl) butanoic acid (3-ATfBA) was evaluated, wherein 3-ATfBA was synthesized with good conversion (65%). [ABSTRACT FROM AUTHOR]