title: Proteases in Escherichia coli and Staphylococcus aureus confer reduced susceptibility to lactoferricin B.
abstract: Lactoferricin B is a cationic antimicrobial peptide derived from the N-terminal part of bovine lactoferrin. The effect of bacterial proteases on the antibacterial activity of lactoferricin B towards Escherichia coli and Staphylococcus aureus was investigated using various protease inhibitors and protease-deficient E. coli mutants. Sodium-EDTA, a metalloprotease inhibitor, was the most efficient inhibitors in both species, but combinations of sodium-EDTA with other types of protease inhibitor gave a synergic effect. The results indicate that several groups of proteases are involved in resistance to lactoferricin B in both E. coli and S. aureus. We also report that genetic inactivation of the heat shock-induced serine protease DegP increased the susceptibility to lactoferricin B in E. coli, suggesting that this protease, at least, is involved in reduced susceptibility to lactoferricin B.
mesh_terms: D000818:Animals; D002417:Cattle; D024881:Drug Resistance, Bacterial / Q000502:physiology*; D010450:Endopeptidases / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology* / Q000302:isolation & purification; D006801:Humans; D007781:Lactoferrin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000201:enzymology* / Q000302:isolation & purification
chemical_list: D011480:Protease Inhibitors; C082171:lactoferricin B; D010450:Endopeptidases; D007781:Lactoferrin