| 초록 |
For simultaneous synthesis of enatiomerically pure L-amino acids and (R)-chiral amines, α and ω-transaminase coupling reaction system was designed. α-Transaminase reaction with a low equilibrium constant can be driven to product formation via coupled reaction with ?-transaminase with a high equilibrium constant. The coupled reaction produced L-amino acids with the yield of 78-90% (>99% ee) and resolved racemic amines into (R)-form with ee values of 83-99%. The alanine transaminase and the ω-transaminase coupling reaction exhibited alanine-pyruvate shuttling, whereas the strain producing aromatic transaminase and the ?-transamianse consumes the pyruvate generated from TyrAT reaction as a substrate for the coupled ?-transaminase reaction. Using this coupling reaction, various L-amino acids can be produced according to the corresponding substrate specificity of ?-transaminases. The common problem of low equilibrium constant of ?-transaminase can be efficiently overcome by the coupling with ω-transaminase. The product inhibition of ω-transaminase by ketone at high concentration of amine was overcome by organic-aqueous biphasic reaction.
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