AaLpxC was preincubated alone or in the presence of TU-514, CHIR-090, or both TU-514 and CHIR-090. Samples were then assayed for activity. Control reactions were performed in which AaLpxC was assayed alone or with TU-514, CHIR-090, or both TU-514 and CHIR-090, but without a preincubation. The remaining activity is expressed as the percent of the uninhibited control.