Whole-cell catalysis by surface display of fluorinase on Escherichia coli using N-terminal domain of ice nucleation protein

Abstract

BackgroundFluorinases play a unique role in producing fluorinated organic molecules through a biological method. Whole-cell catalysis is a better choice in the large-scale fermentation processes, and over 60% of industrial biocatalysis uses this method. However, the in vivo catalytic efficiency of fluorinases is stuck with the mass transfer of the substrates.ResultsA gene sequence encoding a protein with fluorinase function was fused to the N-terminal of ice nucleation protein, and the fused protein was expressed in Escherichia coli BL21(DE3) cells. SDS-PAGE and Immunofluorescence microscopy were used to demonstrate the surface localization of the fusion protein. The fluorinase-containing surface display system with improved whole-cell catalytic efficiency and stability showed low growth pressure on the protein expressing host. The conversion rate of 5′-fluorodeoxyadenosine (5′-FDA) from S-adenosyl-L-methionine (SAM) achieved 55%.ConclusionsHere, we created the fluorinase-containing surface display system on E.coli cells for the first time. The fluorinase was successfully displayed on the surface of Escherichia coli and maintained its catalytic activity. The surface display offers a new solution for the industrial application of biological fluorination.