AUTHOR=Enoki Junichi , Meisborn Jaqueline , Müller Ann-Christin , Kourist Robert
TITLE=A Multi-Enzymatic Cascade Reaction for the Stereoselective Production of γ-Oxyfunctionalyzed Amino Acids
JOURNAL=Frontiers in Microbiology
VOLUME=7
YEAR=2016
URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00425
DOI=10.3389/fmicb.2016.00425
ISSN=1664-302X
ABSTRACT=
A stereoselective three-enzyme cascade for synthesis of diasteromerically pure γ-oxyfunctionalized α-amino acids was developed. By coupling a dynamic kinetic resolution (DKR) using an N-acylamino acid racemase (NAAAR) and an L-selective aminoacylase from Geobacillus thermoglucosidasius with a stereoselective isoleucine dioxygenase from Bacillus thuringiensis, diastereomerically pure oxidized amino acids were produced from racemic N-acetylamino acids. The three enzymes differed in their optimal temperature and pH-spectra. Their different metal cofactor dependencies led to inhibitory effects. Under optimized conditions, racemic N-acetylmethionine was quantitatively converted into L-methionine-(S)-sulfoxide with 97% yield and 95% de. The combination of these three different biocatalysts allowed the direct synthesis of diastereopure oxyfunctionalized amino acids from inexpensive racemic starting material.