How to optimise the immobilization of amino transaminases on synthetic enzyme carriers, to achieve up to a 13-fold increase in performances
Herein we report on the successful immobilization of a transaminase on functionalised methacrylic supports commercially produced by Purolite. The (R)-selective amine transaminase ATA-025 was immobilized on hydrophobic enzyme carrier resins ECR8806F, ECR8804F, ECR1030M by adsorption. The immobilization performance was tested in the model reaction of acetophenone production from rac-1-phenylethylamine and pyruvic acid. Immobilization on ECR8806F was optimised and achieved a 13-fold increase in the final enzyme activity (from 0.33 UAPH / gdry to 4.35 UAPH / gdry).
Transaminases (EC 2.6.1) are enzymes able to catalyse the transfer of an amine group from an amino-donor, usually an arylamine or amino acid, to a prochiral ketone acceptor, yielding a second chiral amine and a ketone by-product (1). There is an increasing interest in these enzymes due to their ability to produce chiral amines, compounds of great interest as intermediates, or final products in pharmaceutical and agrochemical industries (2, 3).
Savile et al have reported a study for evolution of transaminases to create new variants, with broad applicability towards the synthesis of chiral amines that can accept organic solvents and high concentration of substrates (4). The engineering of transaminases has created enzymes suitable for industrial processes, (5, 6) and immobilization on polymers can be performed using either covalent immobilization using epoxy activated beads, or adsorption on hydrophobic carrier for use in neat organic solvent (4, 7).
Adsorption of transaminase is cost effective and easy to scale up, and screening of different carriers with different chemical and physical properties is cruc ...