Functionalization of Membranes with Ompf Porins

Even more impressive than artificial membranes are the biological membranes that nature offers, with higher selectivity, resistance to fouling, and regenerative capabilities. Thus, incorporating into membranes the structures responsible for high biological performance could potentially increase stimulus-responsive behavior and salt rejection while attaining larger fluxes than other highly selective membranes. In order to achieve proper alignment and stabilization of biomolecules, certain techniques are utilized. This research first explains the process and behavior of layer-by-layer assembly of polycations and polyanions. Multilayers of electrolytes have been shown to increase the number of immobilized biomolecules by 25-fold with insignificant distortion of biomolecules.

            Porins, or cylindrical beta barrel protein pores, are the biomolecule of interest in this research. Membranes with solely porins acting as their channels could produce novel behaviors and transport only small metabolites while rejecting macromolecules. These beta barrel proteins are immobilized within the pores of polyvinylidene fluoride (PVDF) membranes using layers of poly(acrylic acid) (PAA) hydrogel intercalated through in situ free radical polymerization and poly(allylamine) hydrochloride (PAH) accumulated during convective flow. The major challenge with this study is achieving an orientation of the porins parallel to the length of membrane pores so fluids may flow through their channels. This poster examines methods of functionalizing the membranes with OmpF porins from Escherichia coli and characterization of the membrane during each stage of the process, including zeta potential analyses, pH responsiveness, changes in flux, and sugar rejection. Characterization of solutions containing OmpF porins is also expounded.      

Acknowledgement: This research is made possible by NSF KY EPSCOR and by NIH-NIEHS-SRC.