Discovery and structure–activity relationship analysis of Staphylococcus aureus sortase A inhibitors

Methicillin resistant Staphylococcus aureus (MRSA) is a major health problem that has created a pressing need for new antibiotics. Compounds that inhibit the S. aureus SrtA sortase may function as potent anti-infective agents as this enzyme attaches virulence factors to the cell wall. Using high-throughput screening, we have identified several compounds that inhibit the enzymatic activity of the SrtA. A structure–activity relationship (SAR) analysis led to the identification of several pyridazinone and pyrazolethione analogs that inhibit SrtA with IC50 values in the sub-micromolar range. Many of these molecules also inhibit the sortase enzyme from Bacillus anthracis suggesting that they may be generalized sortase inhibitors.

Model of the Staphylococcus aureus sortase enzyme bound to a small molecule.Figure optionsDownload as PowerPoint slide