title: Purification of a Novel Bacteriocin-Like Inhibitory Substance Produced by Enterococcus faecium ICIS 8 and Characterization of Its Mode of Action.
abstract: OBJECTIVE
  The aim of this work was to purify and characterize a bacteriocin-like antimicrobial substance produced by an antagonistic active strain of Enterococcus faecium.
  
  
  RESULTS
  A novel bacteriocin-like inhibitory substance (BLIS) produced by the E. faecium ICIS 8 strain was purified and characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and N-terminal amino acid sequencing revealed the following partial sequence: NH2-APKEKCFPKYCV. The proteinaceous nature of purified BLIS was assessed by treatment with proteolytic enzyme. Studies of the action of BLIS using bacteriological and bioluminescence assays revealed a dose-dependent inhibition of Listeria monocytogenes 88BK and Escherichia coli K12 TG1 lac::lux viability. The interaction of the BLIS with the bacterial surface led to the compensation of a negative charge value, as shown by zeta-potential measurements. Assessments of membrane integrity using fluorescent probes and atomic force microscopy revealed the permeabilization of the cellular barrier structures in both L. monocytogenes and E. coli.
  
  
  CONCLUSIONS
  The novel BLIS from E. faecium ICIS 8 was characterized by a unique primary peptide sequence and exerted bactericidal activity against L. monocytogenes and E. coli by disrupting membrane integrity.
authors: 1 Institute of Cellular and Intracellular Symbiosis , Russian Academy of Sciences, Orenburg, Russian Federation.|2 Orenburg State University , Orenburg, Russian Federation.
authors: Alexey S
authors: AS
authors: Vasilchenko
authors: 3 Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry , Russian Academy of Sciences, Moscow, Russian Federation.|4 Gause Institute of New Antibiotics , Moscow, Russian Federation.
authors: Eugene A
authors: EA
authors: Rogozhin
authors: 1 Institute of Cellular and Intracellular Symbiosis , Russian Academy of Sciences, Orenburg, Russian Federation.
authors: Alexander V
authors: AV
authors: Valyshev
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000302:isolation & purification* / Q000494:pharmacology; D001430:Bacteriocins / Q000096:biosynthesis / Q000302:isolation & purification* / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects*; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004591:Electrophoresis, Polyacrylamide Gel; D016984:Enterococcus faecium / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D055672:Static Electricity
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins
keywords: antimicrobial peptides; atomic force microscopy; bacterial biolumenescence; bacteriocin; enterocin; mode of action