title: High affinity glycodendrimers for the lectin LecB from Pseudomonas aeruginosa.
abstract: Following an iterative oxime ligation procedure, cyclopeptide (R) and lysine-based dendron (D) were combined in all possible arrangements and successively functionalized with α-fucose and β-fucose to provide a new series of hexadecavalent glycosylated scaffolds (i.e., scaffolds RD16, RR16, DR16, and DD16). These compounds and smaller analogs (tetra- and hexavalent scaffolds R4 and R6) were used to evaluate the influence of the ligand valency and architecture, and of the anomer configuration in the binding to the αFuc-specific lectin LecB from Pseudomonas aeruginosa . Competitive enzyme-linked lectin assays (ELLA) revealed that only the RD16 architecture displaying αFuc (9A) reaches strong binding improvement (IC50 of 0.6 nM) over αMeFuc, and increases the α-selectivity of LecB. Dissociation constant of 28 nM was measured by isothermal titration micorcalorimetry (ITC) for 9A, which represents the highest affinity ligand ever reported for LecB. ITC and molecular modeling suggested that the high affinity observed might be due to an aggregative chelate binding involving four sugar head groups and two lectins. Interestingly, unprecedented binding effects were observed with β-fucosylated conjugates, albeit being less active than the corresponding ligands of the αFuc series. In particular, the more flexible lysine-based dendritic structures (15B and 18B) showed a slight inhibitory enhancement in comparison with those having cyclopeptide core.
authors.affiliation: Département de Chimie Moléculaire, UMR-CNRS 5250 & ICMG FR 2607 , Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Berthet
authors.forename: Baptiste
authors.initials: B
authors.lastname: Thomas
authors.forename: Isabelle
authors.initials: I
authors.lastname: Bossu
authors.forename: Emilie
authors.initials: E
authors.lastname: Dufour
authors.forename: Emilie
authors.initials: E
authors.lastname: Gillon
authors.forename: Julian
authors.initials: J
authors.lastname: Garcia
authors.forename: Nicolas
authors.initials: N
authors.lastname: Spinelli
authors.forename: Anne
authors.initials: A
authors.lastname: Imberty
authors.forename: Pascal
authors.initials: P
authors.lastname: Dumy
authors.forename: Olivier
authors.initials: O
authors.lastname: Renaudet
mesh_terms: D050091:Dendrimers / Q000737:chemistry* / Q000494:pharmacology*; D006020:Glycopeptides / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D008958:Models, Molecular; D011485:Protein Binding; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000378:metabolism*
chemical_list: D050091:Dendrimers; D006020:Glycopeptides; C534600:LecB protein, Pseudomonas aeruginosa; D037102:Lectins