title: Anti-complement effects of lactoferrin-derived peptides.
abstract: Lactoferrin is an important biological molecule with many functions such as modulation of the inflammatory response, iron metabolism and antimicrobial defense. One effect of lactoferrin is the inhibition of the classical complement pathway. This study reports that antimicrobial peptides derived from the N-terminal region from both human and bovine lactoferrin, lactoferricin H and lactoferricin B, respectively, inhibit the classical complement pathway. No inhibitory effect of these peptides was observed on the alternative complement pathway in an AP50 assay. However, lactoferricin B reduced the inhibitory properties of serum against Escherichia coli in a concentration dependent manner. These results suggest that the N-terminal region of lactoferrin is the important part in the inhibition of complement activation and that these peptides possess other important properties than their antimicrobial effect.
authors.affiliation: Department of Medical Microbiology, University Hospital of North Norway, P.O. Box 56, N-9038 Tromsø, Norway. orjan.samuelsen@unn.no
authors.forename: Ørjan
authors.initials: Ø
authors.lastname: Samuelsen
authors.forename: Hanne H
authors.initials: HH
authors.lastname: Haukland
authors.forename: Hilde
authors.initials: H
authors.lastname: Ulvatne
authors.forename: Lars H
authors.initials: LH
authors.lastname: Vorland
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle; D003170:Complement Pathway, Alternative / Q000187:drug effects / Q000276:immunology; D003171:Complement Pathway, Classical / Q000187:drug effects* / Q000276:immunology*; D003165:Complement System Proteins / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology; D005260:Female; D006461:Hemolysis / Q000276:immunology; D006801:Humans; D007781:Lactoferrin / Q000031:analogs & derivatives* / Q000276:immunology / Q000494:pharmacology*; D008297:Male; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D010446:Peptide Fragments; C082171:lactoferricin B; D003165:Complement System Proteins; D007781:Lactoferrin