Comparison of the IC50s of inhibitors of peptidoglycan synthesis when reaction products were captured by WGA-SPA beads in the presence or the absence of Triton X-100

Drug (concn units)Enzyme targetaIC50Maximum % inhibitionb (no detergent)
With Triton X-100Without detergentc
Tunicamycin (μg/ml)MraY11.2100
Nisin (μg/ml)MurG131380
Vancomycin (μM)MraY, MurG, TG, TP187380
Ristocetin (μg/ml)MraY, MurG, TG, TP68250
Bacitracin (U/ml)Lipid pyrophosphorylase0.30.368
Moenomycin (μM)TG0.01>335
Penicillin G (μM)TP3>30030
Ampicillin (μM)TP10>1,00040
Meropenem (μM)TP87>3,0000
  • a TG, transglycosylase; TP, transpeptidase.

  • b The maximum inhibition observed for the range of drug concentrations tested.

  • c The inhibition in the absence of detergent varied somewhat between experiments but seldom reached 50% inhibition for either moenomycin or the β-lactams tested.