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=<p>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 <italic>N</italic>-acylamino acid racemase (NAAAR) and an L-selective aminoacylase from <italic>Geobacillus thermoglucosidasius</italic> with a stereoselective isoleucine dioxygenase from <italic>Bacillus thuringiensis</italic>, diastereomerically pure oxidized amino acids were produced from racemic <italic>N</italic>-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 <italic>N</italic>-acetylmethionine was quantitatively converted into L-methionine-(<italic>S</italic>)-sulfoxide with 97% yield and 95% <italic>de</italic>. The combination of these three different biocatalysts allowed the direct synthesis of diastereopure oxyfunctionalized amino acids from inexpensive racemic starting material.</p>