Directed Immobilisation of Modificated Galactitol-Dehydrogenase on Gold Electrodes for Electrochemical Cofactor Regeneration

A supplemental cysteine-tag modification of the enzyme galactitol dehydrogenase (GatDH), expressed in Escherichia coli has enabled a directed and covalent immobilisation of the protein on gold surfaces without secondary linkers. The successful enzyme immobilisation was verified by SPR measurements, and the activity of the immobilized GatDH was demonstrated by cyclic voltammetry (CV) while NAD+ and the redox mediator 4-carboxy-2,5,7-trinitrofluorenyliden-malonnitrile (CTFM) were both kept in solution. The results represent a proof of concept for the development of electrochemical reactors for the generation of enantiopure fine chemicals as building blocks for pharmaceutical products.