Generation of Urea Gradient by Electroosmosis Through Ultrafiltration Membrane and Its Application to Protein Refolding
基于超滤膜电渗流动建立尿素梯度及其应用于蛋白质复性

An ultrafiltration membrane-spaced 5-compartment electrolyzer was developed for protein refolding conducted in a longitudinal concentration gradient of urea in the central compartment, as a results of urea transport between central and elution compartment by electroosmosis through two ultrafiltration membranes. A mathematical model describing urea gradient as a function of operation parameters was established and its validity was examined by experiments. The longitudinal gradient of urea can be maintained through a suitable choice of operation parameters based on the simulation. Refolding of bovine serum by the urea gradient established in electric field and by direct oxidative dilution were performed, and evaluated by non-reductive SDS-PAGE and fluoresence spectrum, indicating the structural similarity between the BSA refolded in electric field to that of native BSA.