Biocatalytic production of (S)-2-aminobutanamide by a novel d-aminopeptidase from Brucella sp. with high activity and enantioselectivity

Abstract As the important chiral building block of levetiracetam, the synthesis of ( S )-2-aminobutanamide has attracted a great deal of attention. The d -aminopeptidase catalyzed kinetic resolution of 2-aminobutanamide was demonstrated as an effective strategy for ( S )-2-aminobutanamide production. In this study, a novel d -aminopeptidase from Brucella sp. ( Bs -Dap) was screened and systematically characterized. The enzyme exhibited maximum activity at 45 °C, pH 8.0 and it showed relatively low K m value toward 2-aminobutanamide, indicating its high affinity to the substrate. Kinetic resolution of 300 g/L 2-aminobutanamide by recombinant Escherichia coli whole cells (4 g/L wet cell weight) resulted in 50% conversion and >99% e.e. within 80 min. The catalytic properties of Bs -Dap demonstrated its great potential for industrial production of ( S )-2-aminobutanamide.