Biological effects differ depending on the enantiomeric form of a substance. In a racemate (mixture of two enantiomers), one enantiomer may be fully active whereas the other enantiomer is inactive. This could mean that only a fraction of a chemically synthesized material is functional, increasing the cost of production. Chemical synthesis of only the desired enantiomer may be extremely complicated but can be simplified by use of enzymes catalyzing chiral reactions.
Transaminases are a group of enzymes that catalyze the transfer of an amino group from an amine to an acceptor, creating a ketone and an amino acid with a single chirality. There is great interest in the use of these enzymes for chiral production of chemical precursors. Currently, chiral production is usually performed by overexpressing the enzyme in a suitable host and the crude extract of the material is used for mixing with the precursor to be modified. The method is relatively straightforward but has the drawback that purification of the product becomes more complex due to the addition of large amounts of biomass without catalytic function. The use of purified enzyme reduces the purification efforts required to some extent