Microarray-Based Study of CarbohydrateProtein Binding

To develop a novel high-throughput tool for monitoring carbohydrate–protein interactions, carbohydrate or glycoprotein microarrays have been prepared for binding with lectins. The interaction events are marked by attachment of fluorescent dyes and gold nanoparticles. The attachment of the fluorescent dyes and gold nanoparticles is achieved by standard avidin–biotin chemistry. The detection principle is fluorescence or resonance light scattering (RLS). The electroless deposition of silver onto the gold particles has been employed for RLS signal enhancement. Well-defined recognition systems, three monosaccharides (Man-α, Glc-β, and Gal-β) or three glycoproteins (Asf, RNase A, and RNase B) with two lectins (ConA and RCA120), are chosen here to establish the microarray-based assay, respectively. Highly selective recognition of carbohydrate–protein down to 25.6 pg/mL for RCA120 in solution and 8 μM for Gal-β and 32 ng/mL for Asf on the microarray spots is demonstrated.