title: Defensins mediate the microbicidal activity of human neutrophil granule extract against Acinetobacter calcoaceticus.
abstract: An acid extract of human neutrophil granules was fractionated on a Sephadex G-100 column and tested for microbicidal activity against Acinetobacter calcoaceticus HO-1 as described previously (M.C. Modrzakowski and C. M. Paranavitana, Infect. Immun. 32:668-674, 1981). The low-molecular-weight protein fraction, peak D, accounted for about 30% of the protein and nearly all of the activity of the crude extract against strain HO-1. Peak D protein proved to be a mixture of the three human defensin peptides HNP1, HNP2, and HNP3. Purified defensins reproduced the microbicidal activity of peak D. The data suggest that defensins could play a major role in the killing of A. calcoaceticus by human neutrophils.
mesh_terms: D000150:Acinetobacter / Q000187:drug effects*; D000151:Acinetobacter Infections / Q000276:immunology; D001798:Blood Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009504:Neutrophils / Q000502:physiology*; D023084:alpha-Defensins
chemical_list: D001798:Blood Proteins; D023084:alpha-Defensins; C406413:human neutrophil peptide 1