title: Purification and characterization of staphylococcin BacR1, a broad-spectrum bacteriocin.
abstract: The bacteriocin BacR1 was purified from culture supernatant of Staphylococcus aureus UT0007 by sequential ammonium sulfate precipitation, cation-exchange chromatography, and C4 reverse-phase chromatography steps. Mass spectrographic analysis indicated that the purified peptide has a molecular mass of 3,338 Da. It is resistant to environmental conditions, retaining full biological activity after exposure to pH extremes (pHs 3 to 11), heating at 95 degrees C for 15 min, and exposure to strong chaotropic agents. BacR1 was destroyed with a complete loss of biological activity after digestion with trypsin and proteinase K. Amino acid sequence analysis revealed a high concentration of Asx, Gly, and Pro residues and a high proportion of hydrophobic amino acids. The peptide is bactericidal and kills in a dose-dependent manner, but it does not lyse log-phase cells of Corynebacterium renale, the routine indicator organism for bacteriocin assay. A specific receptor for binding was detected on sensitive cells but not on insensitive cells. Competition assays showed that UV-inactivated cells could protect susceptible cells from antibacterial action. A partial inhibitory spectrum revealed that organisms from the following genera are susceptible: Staphylococcus, Streptococcus, Corynebacterium, Haemophilus, Bordetella, Moraxella, Pasteurella, Neisseria, and Bacillus.
authors.affiliation: Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City 73190, USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Crupper
authors.forename: A J
authors.initials: AJ
authors.lastname: Gies
authors.forename: J J
authors.initials: JJ
authors.lastname: Iandolo
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification*; D001419:Bacteria / Q000187:drug effects; D001430:Bacteriocins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; C017724:staphylococcin