Azide solid support for 3'-conjugation of oligonucleotides and their circularization by click chemistry.

International audienc

5'-Bis-conjugation of oligonucleotides by amidative oxidation and click chemistry.

International audienc

Oligonucleotide carbohydrate-centered galactosyl cluster conjugates synthesized by click and phosphoramidite chemistries.

International audienc

Quantitative analysis (Kd and IC50) of glycoconjugates interactions with a bacterial lectin on a carbohydrate microarray with DNA Direct Immobilization (DDI)

International audienceNowadays, there is a great interest for understanding the structure/function relationship governing recognition of carbohydrates by their receptors for the design of new treatments. Indeed, carbohydrates and glycoconjugates play a major role in key biological events such as cell-cell recognition, pathogenesis inflammation, and host pathogen interactions. Pseudomonas aeruginosa (PA) is one of the predominant bacterium encountered in nosocomial infections. PA infections often lead to chronic inflammation and eventually to death despite aggressive antibiotic therapy: the emergence of resistant strains and biofilm formation seems to give a selective advantage to the bacterium. A promising approach is to inhibit the virulence factors of PA such as PA-IL which is a galactose specific lectin. Herein, we develop a microarray to probe the binding of six galacto-conjugates to PA-IL differing by their spatial configuration and geometry. This microsystem is made of 40 independent microwells in which 64 spots of glycoconjugates probes are arrayed by using DNA Directed Immobilization (DDI). This microsystem allows, in a multiplex fashion, qualitative information on the binding by direct fluorescence readout as well as quantitative information by the determination of IC50 values in a competition assay and surface dissociation constants (Kd). According to our data, direct fluorescent signals (FI635), IC50 and Kd values provided similar ranking for glycoconjugates with respect to PA-IL binding thus affording a general tool for the selection of galacto-conjugates displaying the best affinities toward PA-IL

Synthesis of Homo- and Heterofunctionalized Glycoclusters and Binding to Pseudomonas aeruginosa Lectins PA-IL and PA-IIL

International audienceHomo- and heterofunctionalized glycoclusters with galactose and/or fucose residues targeting both PA-IL and PA-IIL lectins of Pseudomonas aeruginosa were synthesized using "Click" chemistry and DNA chemistry. Their binding to lectins (separately or in a mixture) was studied using a DNA Directed Immobilization carbohydrate microarray. Homoglycoclusters bind selectively to their lectin while the heteroglycocluster binds simultaneously both lectins with a slight lower affinity

Design of triazole-tethered glycoclusters exhibiting three different spatial arrangements and comparative study of their affinities towards PA-IL and RCA 120 by using a DNA-based glycoarray.

International audienc

Synthesis of a Library of Fucosylated Glycoclusters and Determination of their Binding toward Pseudomonas aeruginosa Lectin B (PA-IIL) Using a DNA-Based Carbohydrate Microarray

International audiencePseudomonas aeruginosa (PA) is a Gram negative opportunistic pathogen and is the major pathogen encounter in the cystic fibrosis (CF) lung airways. It often leads to chronic respiratory infection despite aggressive antibiotic therapy due to the emergence of resistant strains and to the formation of biofilm. The lectin PA-IIL (LecB) is a fucose-specific lectin from PA suspected to be involved in host recognition/adhesion and in biofilm formation. Thus, it can be foreseen as a potential therapeutic target. Herein, 16 fucosylated glycoclusters with antenna-like, linear, or crownlike spatial arrangements were synthesized using a combination of DNA solid-phase synthesis and alkyne azide 1,3-dipolar cycloaddition (CuAAC). Their binding properties toward PA-IIL were then evaluated based on DNA directed immobilization (DDI) carbohydrate microarray. Our results suggested that the antenna-like scaffold was preferred to linear or crown-like glycoclusters. Among the crown-like carbohydrate centered fucosylated glycoclusters, mannose-based core was better than glucose- and galactose-based ones. The influence of the linker arm was also evaluated, and long linkers between fucoses and the core led to a slight better binding than the short ones

Biopuce à Glycocluster pour la mesure d’affinité des interactions glycoclusters/lectines

International audienc

Biopuce à Glycocluster pour la mesure d’affinité des interactions glycoclusters/lectines

International audienc