title: Fluorophore-labeled, peptide-based glycoclusters: synthesis, binding properties for lectins, and detection of carbohydrate-binding proteins in cells.
abstract: A facile and efficient solid-phase synthesis of linear peptide-based glycoclusters with various valences and different spatial arrangements of the sugar ligands is described. The synthetic strategy includes 1) solid-phase synthesis of fluorophore-labeled, alkyne-containing peptides, 2) coupling of azide-linked, unprotected mono-, di-, and trisaccharides to the alkyne-conjugated peptides on a solid support by click chemistry, and 3) release of the fluorophore-labeled glycoclusters from the solid support. By using this methodology, 32 fluorescent glycoclusters with a valence ranging from 1 to 4 and different spatial arrangements of the sugar ligands were prepared. Lectin-binding properties of the glycoclusters were initially examined by using microarrays immobilized by various lectins. These glycoclusters were then employed to detect the cell-surface carbohydrate-binding proteins in bacteria. Finally, the uptake of glycoclusters by mammalian cells through receptor-mediated endocytosis was evaluated. The results, obtained from the in vitro and in vivo studies, indicate that the binding affinities toward immobilized and cell-surface proteins are highly dependent on the valence and spatial arrangements of the sugar ligands in glycoclusters.
authors.affiliation: Center for Biofunctional Molecules, Department of Chemistry, Yonsei University, Seoul, 120-749, Korea.
authors.forename: Xizhe
authors.initials: X
authors.lastname: Tian
authors.forename: Jaeyoung
authors.initials: J
authors.lastname: Pai
authors.forename: Kyung-Hwa
authors.initials: KH
authors.lastname: Baek
authors.forename: Sung-Kyun
authors.initials: SK
authors.lastname: Ko
authors.forename: Injae
authors.initials: I
authors.lastname: Shin
mesh_terms: D057930:Click Chemistry / Q000191:economics / Q000379:methods*; D004705:Endocytosis; D004926:Escherichia coli / Q000737:chemistry; D029968:Escherichia coli Proteins / Q000032:analysis; D005456:Fluorescent Dyes / Q000737:chemistry*; D006020:Glycopeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D056945:Hep G2 Cells; D006801:Humans; D007785:Lactose / Q000737:chemistry / Q000378:metabolism; D037102:Lectins / Q000378:metabolism*; D040081:Protein Array Analysis; D011485:Protein Binding
chemical_list: D029968:Escherichia coli Proteins; D005456:Fluorescent Dyes; D006020:Glycopeptides; D037102:Lectins; D007785:Lactose