Mechanism of action of bacitracin: complexation with metal ion and C 55 -isoprenyl pyrophosphate.
The inhibition by bacitracin of the enzymatic dephosphorylation of C(55)-isoprenyl pyrophosphate is abolished by the addition of chelating agents. If, however, the chelating agent is added after a preincubation of bacitracin with a divalent cation and the lipid substrate, then its addition has little effect, indicating that bacitracin, metal ion, and C(55)-isoprenyl pyrophosphate form a complex. Various divalent cations can participate in complex formation, but monovalent cations are ineffective. A direct demonstration of the formation of a complex between the C(55)-isoprenyl pyrophosphate and bacitracin in the presence of metal ions was obtained. Molecular models that show one possible conformation for a complex between bacitracin and the C(55)-isoprenyl pyrophosphate, in which the metal ion acts as a bridge between the two compounds, are presented.
D001414:Bacitracin; D002462:Cell Membrane; D002614:Chelating Agents; D055598:Chemical Phenomena; D002621:Chemistry; D002850:Chromatography, Gel; D011756:Diphosphates; D013293:Enterococcus faecalis; D008670:Metals; D008837:Micrococcus; D008961:Models, Structural; D010759:Phosphorus Isotopes; D011755:Pyrophosphatases
D002614:Chelating Agents; D011756:Diphosphates; D008670:Metals; D010759:Phosphorus Isotopes; D001414:Bacitracin; D011755:Pyrophosphatases