title: Inhibition of listeriolysin O-induced hemolysis by bovine lactoferrin.
abstract: Lactoferrin (LFR) plays an important role in the anti-microbial defense through iron binding, lipopolysaccharide binding and immunomodulation. In this study, we demonstrate that bovine LFR specifically inhibits the hemolytic activity of listeriolysin O (LLO) produced by Listeria monocytogenes. The hemolytic activity of LLO was completely inhibited in the presence of bovine LFR that was highly purified on two cation-exchange columns, whereas that of streptolysin O or perfringolysin O was not inhibited at all. A rabbit anti-LFR antibody canceled this inhibitory activity of bovine LFR. Although human transferrin exhibits 62% amino acid identity with bovine LFR, human apo-transferrin could not inhibit LLO-induced hemolysis. An increase in the concentration of FeCl3 or the Fe3+-saturation of bovine LFR, however, slightly reduced its inhibition of the hemolysis. The inhibitory activity of bovine LFR was dependent on pH, since it was observed under neutral and alkali conditions, but not under acidic conditions. These results suggest that the inhibition of LLO-induced hemolysis by bovine LFR is influenced by pH and iron ions, both of which may lead to conformational changes of LFR.
authors.affiliation: Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Moriishi
authors.forename: S
authors.initials: S
authors.lastname: Inoue
authors.forename: M
authors.initials: M
authors.lastname: Koura
authors.forename: F
authors.initials: F
authors.lastname: Amano
mesh_terms: D000818:Animals; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D002417:Cattle; D010450:Endopeptidases / Q000737:chemistry; D004912:Erythrocytes / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D006460:Hemolysin Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007501:Iron / Q000097:blood / Q000494:pharmacology; D007781:Lactoferrin / Q000302:isolation & purification / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D012756:Sheep; D013301:Streptolysins / Q000494:pharmacology; D013879:Thioredoxins / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D013301:Streptolysins; C025964:streptolysin O; D013879:Thioredoxins; D007501:Iron; D010450:Endopeptidases; D007781:Lactoferrin; C038705:hlyA protein, Listeria monocytogenes