title: Histone H1: an antimicrobial protein of Atlantic salmon (Salmo salar).
abstract: Antimicrobial activity was detected in acid extracts of liver, intestine, and stomach of healthy Atlantic salmon (Salmo salar). An antimicrobial protein was isolated from salmon liver using acid extraction followed by ammonium sulfate precipitation, large-scale gel filtration chromatography, reverse-phase HPLC, and size exclusion HPLC. The salmon antimicrobial (SAM) protein was found to have a molecular mass of 20,734 Da by MALDI TOF mass spectrometry. Peptide mass fingerprinting and partial sequencing by tandem nanoelectrospray mass spectrometry identified the protein as histone H1. The protein had a minimal inhibitory concentration of 31 microg/mL against E. coli D31 in a plate clearing assay. The effect of the SAM protein on bacterial morphology was indistinguishable from that of (Ala-(8,13,18))-magainin II, as shown by scanning electron microscopy, which suggests that the protein disrupts E. coli membranes in a manner similar to that of most antimicrobial peptides. This protein may act as an antimicrobial in vivo through active secretion or by release from cells during infection-related apoptosis.
authors.affiliation: NRC Institute for Marine Biosciences, 1411 Oxford Street, Halifax, Nova Scotia B3H 3Z1, Canada.
authors.forename: R C
authors.initials: RC
authors.lastname: Richards
authors.forename: D B
authors.initials: DB
authors.lastname: O'Neil
authors.forename: P
authors.initials: P
authors.lastname: Thibault
authors.forename: K V
authors.initials: KV
authors.lastname: Ewart
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000187:drug effects / Q000648:ultrastructure; D006657:Histones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D020317:Salmo salar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014020:Tissue Extracts / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D006657:Histones; D014020:Tissue Extracts