title: Membrane glycoproteomics of fetal lung fibroblasts using LC/MS.
abstract: Some aberrant N-glycosylations are being used as tumor markers, and glycoproteomics is expected to provide novel diagnosis markers and targets of drug developments. However, one has trouble in mass spectrometric glycoproteomics of membrane fraction because of lower intensity of glycopeptides in the existence of surfactants. Previously, we developed a glycopeptide enrichment method by acetone precipitation, and it was successfully applied to human serum glycoproteomics. In this study, we confirmed that this method is useful to remove the surfactants and applicable to membrane glycoproteomics. The glycoproteomic approach to the human fetal lung fibroblasts membrane fraction resulted in the identification of over 272 glycoforms on 63 sites of the 44 glycoproteins. According to the existing databases, the structural features on 41 sites are previously unreported. The most frequently occurring forms at N-glycosylation site were high-mannose type containing nine mannose residues (M9) and monosialo-fucosylated biantennary oligosaccharides. Several unexpected N-glycans, such as fucosylated complex-type and fucosylated high-mannose and/or fucosylated pauci-mannose types were found in ER and lysosome proteins. Our method provides new insights into transport, biosynthesis, and degradation of glycoproteins.
authors.affiliation: Department of Medical Life Science, Graduate School of Medical Life Science, Yokohama City University, Tsurumi-ku, Yokohama, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takakura
authors.affiliation: Division of Biological Chemistry and Biologicals, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Tada
authors.affiliation: Department of Medical Life Science, Graduate School of Medical Life Science, Yokohama City University, Tsurumi-ku, Yokohama, Japan.
authors.forename: Nana
authors.initials: N
authors.lastname: Kawasaki
mesh_terms: D002240:Carbohydrate Sequence; D002460:Cell Line; D002853:Chromatography, Liquid / Q000379:methods; D005347:Fibroblasts / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D006031:Glycosylation; D006801:Humans; D008168:Lung / Q000166:cytology*; D008565:Membrane Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D040901:Proteomics / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D006023:Glycoproteins; D008565:Membrane Proteins
keywords: Glycoproteomics; LC/MS; Membrane glycoproteins; Microheterogeneity