title: Purification and characterization of enterocin LR/6, a bacteriocin from Enterococcus faecium LR/6.
abstract: Enterocin LR/6, a bacteriocin obtained from the culture filtrate of Enterococcus faecium strain LR/6, has been purified to homogeneity using ammonium sulfate precipitation, cation-exchange chromatography, gel-filtration, and checked on reverse-phase high-performance liquid chromatography. It is active at high temperatures (boiling as well as autoclaving) and over a wide range of pH (2.0-8.0). Also, it is sensitive to a number of proteolytic enzymes but is stable in the presence of surfactants and organic solvents. The protein could be stored at least up to 1 year at low temperatures (4 degrees C and -20 degrees C) without any loss of activity. The N-terminal sequence of enterocin LR/6 showed no homology with known enterocins or other bacteriocins present in the database, suggesting it to be a novel enterocin. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry and tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed its mass to be approximately 6.1 kDa. It showed a bactericidal mode of action against indicator strain, Micrococcus luteus.
authors.affiliation: Department of Genetics, University of Delhi South Campus, New Delhi, India.
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.forename: Santosh Kumar
authors.initials: SK
authors.lastname: Tiwari
authors.forename: Sheela
authors.initials: S
authors.lastname: Srivastava
mesh_terms: D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D001430:Bacteriocins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D016984:Enterococcus faecium / Q000737:chemistry*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D016982:Micrococcus luteus / Q000166:cytology / Q000187:drug effects; D008970:Molecular Weight; D009930:Organic Chemicals / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000378:metabolism; D055550:Protein Stability / Q000187:drug effects; D012997:Solvents / Q000494:pharmacology; D013501:Surface-Active Agents / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D001430:Bacteriocins; D009930:Organic Chemicals; D012997:Solvents; D013501:Surface-Active Agents; D010447:Peptide Hydrolases