title: N-glycan analysis of mannose/glucose specific lectin from Dolichos lablab seeds.
abstract: An affinity purified mannose/glucose specific lectin from the seeds of Dolichos lablab (Indian bean/lablab bean) resolves into five subunits upon SDS-PAGE in the range of Mr 12-20kDa. Partial de novo sequencing of subunits resulted in 88% and 73% sequence coverage for α and β subunits of the cDNA derived FRIL (Flt3 receptor interacting lectin) sequence, respectively and suggested that four bands correspond to the α-subunits while the band of lowest molecular mass is designated as β. It was proposed in an earlier study on FRIL that the difference in molecular mass of α-subunits is due to differences in C-terminal processing and differential N-glycosylation i.e. numbers of N-glycans present (Colucci et al., 1999). Thus, differential N-glycosylation of the purified mannose/glucose specific lectin was unravelled by in-gel trypsin/chymotrypsin digestion of the α-subunits followed by desalting and ZIC-HILIC enrichment of N-glycopeptides. Subsequently, analyses by nano electrospray ionisation quadrupole time of flight mass spectrometry and low-energy collision-induced dissociation experiments revealed the presence of a typical paucimannose type N-glycan (Man2(Xyl)GlcNAc2(Fuc)) in α subunits 2-4.
authors.affiliation: Protein Biochemistry and Glycobiology Laboratory, Department of Biochemistry, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Gnanesh Kumar
authors.initials: GK
authors.lastname: B S
authors.affiliation: Institute for Hygiene, Westfälische Wilhelms-University, Münster, D-48149, Germany.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Pohlentz
authors.affiliation: Institute for Hygiene, Westfälische Wilhelms-University, Münster, D-48149, Germany.
authors.forename: Mona
authors.initials: M
authors.lastname: Schulte
authors.affiliation: Institute for Hygiene, Westfälische Wilhelms-University, Münster, D-48149, Germany. Electronic address: mmormann@uni-muenster.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Mormann
authors.affiliation: Protein Biochemistry and Glycobiology Laboratory, Department of Biochemistry, University of Hyderabad, Hyderabad 500046, India. Electronic address: nsksl@uohyd.ernet.in.
authors.forename: Siva Kumar
authors.initials: SK
authors.lastname: Nadimpalli
mesh_terms: D000595:Amino Acid Sequence; D031294:Dolichos / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D006020:Glycopeptides / Q000737:chemistry; D006031:Glycosylation; D008358:Mannose / Q000737:chemistry*; D008969:Molecular Sequence Data; D037121:Plant Lectins / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*
chemical_list: D006020:Glycopeptides; D037121:Plant Lectins; D011134:Polysaccharides; D005947:Glucose; D008358:Mannose
keywords: Lablab bean; N-glycopeptides; Seed lectin