Kinetic Resolution of Racemic Primary Amines Using Geobacillus stearothermophilus Amine Dehydrogenase Variant

Abstract

A NADH-dependent engineered amine dehydrogenase from Geobacillus stearothermophilus (LE-AmDH-v1) was applied together with a NADH-oxidase from Streptococcus mutans (NOx) for the kinetic resolution of pharmaceutically relevant racemic α-chiral primary amines. The reaction conditions (e. g., pH, temperature, type of buffer) were optimised to yield S-configured amines with up to >99 % ee.

Keywords: amine dehydrogenases; biocatalysis; kinetic resolution; oxidative deamination; α-chiral amines.

Figure 1

Reaction rates for the oxidative KR of rac‐1 a (10 mM) at different pH values using Britton‐Robinson's buffer. Reaction conditions: LE‐AmDH‐v1 (45 μM), NAD⁺ (1 mM), NOx (3 μM), final volume 0.5 mL, at 40 °C. Time range varied from 5 to 40 min.

Figure 2

KR of rac‐1 a (10 mM) catalysed by LE‐AmDH‐v1 (45 μM) and using different types of buffers with NAD⁺ (1 mM) and NOx (3 μM) at 30 °C. (A) Progress of the KR over the time. (B) Variation of the ee of the unreacted enantiomer over the time.

Figure 3

Progress of the KR of rac‐1 a (10 mM) at different temperatures (30 °C–50 °C) catalysed by LE‐AmDH‐v1 (90 μM) with NAD⁺ (1 mM) and NOx (10 μΜ).

Figure 4

Influence of the substrate concentration in the KR of rac‐1 a (10–100 mM) catalysed by LE‐AmDH‐v1 (90 μM) with NAD⁺ (1 mM), NOx (10 μM) and at 30 °C, for 24 h.