title: Deciphering Dorin M glycosylation by mass spectrometry.
abstract: The soft tick, Ornithodoros moubata, is a vector of several bacterial and viral pathogens including Borrelia duttoni, a causative agent of relapsing fever and African swine fever virus. Previously, a sialic acid-specific lectin Dorin M was isolated from its hemolymph. Here, we report on the complete characterization of the primary sequence of Dorin M. Using liquid chromatography coupled to mass spectrometry, we identified three different glycopeptides in the tryptic digest of Dorin M. The peptide, as well as the glycan part of all glycopeptides, were further fully sequenced by means of tandem mass spectrometry (MS2) and multiple-stage mass spectrometry (MS3). Two classical N-glycosylation sites were modified by high-mannose-type glycans containing up to nine mannose residues. The third site bore a glycan with four to five mannose residues and a deoxyhexose (fucose) attached to the proximal N-acetylglycosamine. The microheterogeneity at each site was estimated based on chromatographic behavior of different glycoforms. The fourth, a non-classical N-glycosylation site (Asn-Asn-Cys), was not glycosylated, probably due to the involvement of the cysteine residue in a disulfide bridge.
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i., Vídenská 1083, 142 20 Praha 4, Czech Republic. pman@biomed.cas.cz
authors.forename: Petr
authors.initials: P
authors.lastname: Man
authors.forename: Vojtech
authors.initials: V
authors.lastname: Kovár
authors.forename: Ján
authors.initials: J
authors.lastname: Sterba
authors.forename: Martin
authors.initials: M
authors.lastname: Strohalm
authors.forename: Daniel
authors.initials: D
authors.lastname: Kavan
authors.forename: Petr
authors.initials: P
authors.lastname: Kopácek
authors.forename: Libor
authors.initials: L
authors.lastname: Grubhoffer
authors.forename: Vladimír
authors.initials: V
authors.lastname: Havlícek
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006020:Glycopeptides / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D006031:Glycosylation; D037102:Lectins / Q000737:chemistry*; D008969:Molecular Sequence Data; D026861:Ornithodoros / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D006020:Glycopeptides; D006023:Glycoproteins; D037102:Lectins