Key points are not available for this paper at this time.
Light is used to toggle a photoresponsive mimic of the cofactor pyridoxal phosphate between two isomers, where only one of them can catalyze the racemization of an amino acid. The system is based on creating and breaking electronic communication between the two catalyst components, i.e., an aldehyde and a pyridinium cation.
Wilson et al. (Thu,) studied this question.