Probing carbohydrate-lectin recognition in heterogeneous environments with monodisperse cyclodextrin-based...

Area of Science:

• Carbohydrate Chemistry
• Glycobiology
• Biophysical Chemistry

Background:

• Lectins are proteins that bind carbohydrates, playing crucial roles in biological recognition.
• Glycoclusters, molecules presenting multiple carbohydrate units, are used to study lectin-carbohydrate interactions.
• Understanding how the arrangement and density of different carbohydrate motifs affect lectin binding is key to deciphering biological recognition events.

Purpose of the Study:

• To synthesize β-cyclodextrin (βCD)-scaffolded glycoclusters with controlled displays of α-mannosyl (α-Man) and β-lactosyl (β-Lact) antennas.
• To investigate the mutual influence of varying densities of α-Man and β-Lact motifs on binding properties toward different plant lectins.
• To explore synergistic recognition mechanisms and the lectin cross-linking efficiency of heterogeneous glycoclusters.

Main Methods:

• Synthesis of βCD-scaffolded glycoclusters with defined heterogeneous and homogeneous displays of α-Man and β-Lact.
• Enzyme-linked lectin assay (ELLA) to quantify lectin binding.
• Two-site, sandwich-type ELLA to assess lectin clustering efficiency.
• Turbidity assays to corroborate binding observations.

Main Results:

• Heterogeneous glycoclusters showed enhanced binding of α-Man to concanavalin A (Con A) in the presence of β-Lact, indicating a synergistic
• heterocluster effect.
• The presence of α-Man motifs also enhanced β-Lact binding to peanut agglutinin (PNA) in certain arrangements.
• Heterogeneous glycoclusters exhibited higher lectin clustering efficiency compared to homogeneous ones.
• Lectin cross-linking was sensitive to non-ligand sugar presence, suggesting modulation of recognition.

Conclusions:

• Heterogeneous glycoclusters can exhibit synergistic binding effects, enhancing lectin recognition beyond additive contributions.
• The spatial arrangement and density of different carbohydrate motifs significantly influence lectin binding affinity and specificity.
• These findings provide insights into complex carbohydrate-lectin interactions relevant to biological systems, particularly concerning multivalency and specific recognition.