Exploring inhibitors of the periplasmic chaperone SurA using fluorescence anisotropy

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. Disruption of SurA activity renders the bacterial cell more sensitive to agents that would normally be kept out by outer membrane porins. Here we describe an in vitro screen to test potential small molecule inhibitors of SurA that could be used to decrease the virulence of bacterial cells. Using fluorescence anisotropy, we conduct competitive binding assays using fluorescently-tagged peptides that bind SurA with high affinity and small molecules discovered using in silico screening