title: Structural characterization of the inflammatory moiety of a variable major lipoprotein of Borrelia recurrentis.
abstract: Louse-borne relapsing fever, caused by Borrelia recurrentis, provides one of the best documented examples of the causative role of tumor necrosis factor (TNF) in the pathology of severe infection in humans. We have identified the principal TNF-inducing factor of B. recurrentis as a variable major lipoprotein (Vmp). Here we report the complete gene sequence of Vmp, including its lipoprotein leader sequence. Using metabolically labeled forms of the native Vmp we confirm that the TNF inducing properties are associated with the lipid portion of the molecule. Quadrupole orthogonal time of flight mass spectrometry unequivocally locates the lipidic moiety at the NH(2)-terminal cysteine of the native polypeptide, and indicates the existence of three forms which are consistent with the structures C16:0, C16:0, C16:0 glyceryl cysteine; C18:1, C16:0, C16:0 glyceryl cysteine; and C18:0, C16:0, C16:0 glyceryl cysteine. These data provide the first direct evidence that the TNF inducing lipid modification of native Borrelia lipoproteins is a structural homologue of the murein lipoprotein of Escherichia coli.
authors.affiliation: University Department of Paediatrics, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom.
authors.forename: I G
authors.initials: IG
authors.lastname: Scragg
authors.forename: D
authors.initials: D
authors.lastname: Kwiatkowski
authors.forename: V
authors.initials: V
authors.lastname: Vidal
authors.forename: A
authors.initials: A
authors.lastname: Reason
authors.forename: T
authors.initials: T
authors.lastname: Paxton
authors.forename: M
authors.initials: M
authors.lastname: Panico
authors.forename: A
authors.initials: A
authors.lastname: Dell
authors.forename: H
authors.initials: H
authors.lastname: Morris
mesh_terms: D000954:Antigens, Surface / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D001898:Borrelia / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007249:Inflammation; D008074:Lipoproteins / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D013058:Mass Spectrometry; D009000:Monocytes; D010446:Peptide Fragments / Q000737:chemistry* / Q000494:pharmacology; D012061:Relapsing Fever / Q000382:microbiology; D014357:Trypsin; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
chemical_list: D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D008074:Lipoproteins; D010446:Peptide Fragments; D014409:Tumor Necrosis Factor-alpha; C120881:vmp protein, Borrelia; D014357:Trypsin