TABLE 2.
Comparison of the IC50s of inhibitors on peptidoglycan synthesis, as measured by paper chromatography, with the SPA
| Inhibitor | Enzyme inhibited | IC50
|
|
|---|---|---|---|
| Peptidoglycan (Paper chromatography) | SPA | ||
| Tunicamycin | Translocase | 0.27 μg/ml | 0.28 μg/ml |
| Nisin | Transferase | 0.9 μM | 3.9 μM |
| Vancomycin | Translocase, transferase, and transglycosylase | 13 μM | 22 μM |
| Moenomycin | Transglycosylase | 0.009 μM | 0.01 μM |
| Penicillin | Transpeptidase | No inhibition | 3 μM |
| Ampicillin | Transpeptidase | No inhibition | 8 μM |
| Bacitracin | Lipid pyrophosphorylase | 0.075 U/ml | 0.065 U/ml |
a
For the nisin IC50 determinations, 75 μM UDP–MurNAc-pp was used. Where the purity of the starting material is not defined, the concentrations are expressed in units other than micromolar concentrations. For tunicamycin, the IC50 approximates to ∼0.3 μM.