Elucidating the binding efficacy of β-galactosidase on graphene by docking approach and its potential application in galacto-oligosaccharide production.

Herein, we propose the synthesis and characterization of graphene for the immobilization of β-galactosidase for improved galacto-oligosaccharide (GOS) production. The size of synthesized graphene was observed to be 25 nm by TEM analysis while interaction of enzyme with the nanosupport was observed by FTIR spectroscopy. Docking was obtained using molecular docking program Dock v.6.5 while the visual analyses and illustration of protein-ligand complex were investigated by utilizing chimera v.1.6.2 and PyMOL v.1.3 softwares. Immobilized β-galactosidase (IβG) showed improved stability against various physical and chemical denaturants. Km of IβG was increased to 6.41 mM as compared to 2.38 mM of soluble enzyme without bringing significant change in Vmax value. Maximum GOS content also registered an increase in lactose conversion. The maximum GOS production was achieved by immobilized enzyme at specific temperature and time. Hence, the developed nanosupport can be further exploited for developing a biosensor involving β-galactosidase or for immobilization of other industrially/therapeutically important enzymes.