TRANSAMINASES (TAs)

Transaminases catalyse the transfer of an amino group donor to a carbonyl acceptor substrate using pyridoxal-5’-phosphate (PLP) as a cofactor. These PLP-dependant enzymes are present in many cellular processes actively involved in the biosynthesis and homeostasis of amino acids, aminosugars, polyamines and alkaloids.  ω-Transaminases (ω-TAs) in particular have attracted considerable interest for their use as biocatalysts in the production of chiral amines attaining high regio-, diastereo- and enantioselectivities.  However, their use in industrial applications is hindered by a number of factors such as thermodynamic equilibrium and poor substrate tolerance. Our group in last few years have sought to address these issues via the use of sacrificial cosubstrates as amino donors which are instantly removed from the equilibrium via spontaneous cyclisation.  We have since focussed on expanding the substrate scope to the synthesis of substituted pyrazines and pyrroles and implemented ω-TAs in biocatalytic cascades for the production of natural and non-natural alkaloids.