title: Probing carbohydrate-lectin recognition in heterogeneous environments with monodisperse cyclodextrin-based glycoclusters.
abstract: A series of β-cyclodextrin (βCD)-scaffolded glycoclusters exposing heterogeneous yet perfectly controlled displays of α-mannosyl (α-Man) and β-lactosyl (β-Lact) antennas were synthesized to probe the mutual influence of varying densities of the saccharide motifs in the binding properties toward different plant lectins. Enzyme-linked lectin assay (ELLA) data indicated that the presence of β-Lact residues reinforced binding of α-Man to the mannose-specific lectin concanavalin A (Con A) even though homogeneous β-Lact clusters are not recognized at all by this lectin, supporting the existence of synergic recognition mechanisms (heterocluster effect). Conversely, the presence of α-Man motifs in the heteroglycoclusters also resulted in a binding-enhancing effect of β-Lact toward peanut agglutinin (PNA), a lectin strongly binding multivalent lactosides but having no detectable affinity for α-mannopyranosides, for certain architectural arrangements. Two-site, sandwich-type ELLA data corroborated the higher lectin clustering efficiency of heterogeneous glycoclusters compared with homogeneous displays of the putative sugar ligand with identical valency. A turbidity assay was also consistent with the previous observations. Most revealingly, the lectin cross-linking ability of heterogeneous glycoclusters was sensitive to the presence of high concentrations of the non-ligand sugar, strongly suggesting that "mismatching" saccharide motifs may modulate carbohydrate-lectin specific recognition in a lectin-dependent manner when present in highly dense displays together with the "matching" ligand, a situation frequently encountered in biological systems.
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Profesor García González 1, E-41012 Sevilla, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Gómez-García
authors.forename: Juan M
authors.initials: JM
authors.lastname: Benito
authors.forename: Anna P
authors.initials: AP
authors.lastname: Butera
authors.forename: Carmen
authors.initials: C
authors.lastname: Ortiz Mellet
authors.forename: José M
authors.initials: JM
authors.lastname: García Fernández
authors.forename: José L
authors.initials: JL
authors.lastname: Jiménez Blanco
mesh_terms: D002236:Carbohydrate Conformation; D007785:Lactose / Q000737:chemistry; D008358:Mannose / Q000737:chemistry; D008958:Models, Molecular; D037121:Plant Lectins / Q000378:metabolism*; D047392:beta-Cyclodextrins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D037121:Plant Lectins; D047392:beta-Cyclodextrins; D007785:Lactose; D008358:Mannose