title: Bactericidal actions of a silver ion solution on Escherichia coli, studied by energy-filtering transmission electron microscopy and proteomic analysis.
abstract: Bactericidal actions of the silver ion on Escherichia coli as a model microorganism were studied using energy-filtering transmission electron microscopy (EFTEM), two-dimensional electrophoresis (2-DE), and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS). EFTEM observations demonstrated that the silver ion readily infiltrates the interior of E. coli, contrary to the early hypothesis that it resides initially in the cell membrane area. Furthermore, 2-DE and MALDI-TOF MS indicated that the expression of a ribosomal subunit protein as well as that of some other enzymes and proteins is affected by the silver ion. The present results demonstrate for the first time that one of the major bactericidal functions of the silver ion is its interaction with the ribosome and the ensuing inhibition in expression of the enzymes and proteins essential to ATP production.
authors.affiliation: Research Dept. 8, Devices Technology Research Laboratories, Corporate Research and Development Group, Sharp Corporation, 2613-1, Ichinomoto-cho, Tenri, Nara, Japan. yamanaka.mikihiro@sharp.co.jp
authors.forename: Mikihiro
authors.initials: M
authors.lastname: Yamanaka
authors.forename: Keita
authors.initials: K
authors.lastname: Hara
authors.forename: Jun
authors.initials: J
authors.lastname: Kudo
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015180:Electrophoresis, Gel, Two-Dimensional; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism*; D046032:Microscopy, Energy-Filtering Transmission Electron; D020543:Proteome; D012834:Silver / Q000494:pharmacology*; D012996:Solutions; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D020543:Proteome; D012996:Solutions; D012834:Silver