title: Sialoglycoproteins and N-glycans from secreted exosomes of ovarian carcinoma cells.
abstract: Exosomes consist of vesicles that are secreted by several human cells, including tumor cells and neurons, and they are found in several biological fluids. Exosomes have characteristic protein and lipid composition, however, the results concerning glycoprotein composition and glycosylation are scarce. Here, protein glycosylation of exosomes from ovarian carcinoma SKOV3 cells has been studied by lectin blotting, NP-HPLC analysis of 2-aminobenzamide labeled glycans and mass spectrometry. An abundant sialoglycoprotein was found enriched in exosomes and it was identified by peptide mass fingerprinting and immunoblot as the galectin-3-binding protein (LGALS3BP). Exosomes were found to contain predominantly complex glycans of the di-, tri-, and tetraantennary type with or without proximal fucose and also high mannose glycans. Diantennary glycans containing bisecting N-acetylglucosamine were also detected. This work provides detailed information about glycoprotein and N-glycan composition of exosomes from ovarian cancer cells, furthermore it opens novel perspectives to further explore the functional role of glycans in the biology of exosomes.
authors.affiliation: Laboratory of Glycobiology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: Cristina
authors.initials: C
authors.lastname: Escrevente
authors.forename: Nicolas
authors.initials: N
authors.lastname: Grammel
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kandzia
authors.forename: Johannes
authors.initials: J
authors.lastname: Zeiser
authors.forename: Erin M
authors.initials: EM
authors.lastname: Tranfield
authors.forename: Harald S
authors.initials: HS
authors.lastname: Conradt
authors.forename: Júlia
authors.initials: J
authors.lastname: Costa
mesh_terms: D000951:Antigens, Neoplasm / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D055354:Exosomes / Q000378:metabolism*; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008351:Mannans / Q000378:metabolism*; D008969:Molecular Sequence Data; D010051:Ovarian Neoplasms; D011134:Polysaccharides / Q000378:metabolism; D012795:Sialoglycoproteins / Q000378:metabolism*; D016326:Extracellular Matrix Proteins
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D006023:Glycoproteins; D008351:Mannans; D011134:Polysaccharides; D012795:Sialoglycoproteins; C081856:LGALS3BP protein, human; D016326:Extracellular Matrix Proteins