A Photoregulated Racemase Mimic.

The racemase enzymes convert L-amino acids to their D-isomer. The reaction proceeds through a stepwise deprotonation-reprotonation mechanism that is assisted by a pyridoxal phosphate (PLP) coenzyme. This work reports a PLP-photoswitch-imidazole triad where the racemization reaction can be controlled by light by tweaking the distance between the basic residue and the reaction centre.