Expression and Purification of the Periplasmic Chaperone SurA

Science Center, Bent Corridor

A requirement for cell homeostasis is the correct functioning of chaperones, which inhibit the aggregation of other proteins in the cell. The chaperone SurA, present in gram-negative bacteria, prevents the aggregation of outer membrane porins as they traverse the aqueous periplasm. Experiments have shown that disruption of SurA renders the bacterial cell more sensitive to agents that would normally be kept out by outer membrane porins. We aim to develop an in vitro screen to test potential small molecule inhibitors of SurA that could be used to decrease the virulence of bacterial cells. In order to carry out these screens, we need solutions of SurA at high concentrations. Using the gram-negative bacterium E. coli, we have optimized a protocol for the expression and purification of high levels of SurA.