Sensing lectin–glycan interactions using lectin super-microarrays and glycans labeled with dye-doped silica nanoparticles

Abstract

A new microarray platform, based on lectin super-microarrays and glycans labeled with dye-doped nanoparticles, has been developed to study glycan-lectin interactions. Glycan ligands were conjugated onto fluorescein-doped silica nanoparticles (FSNPs) using a general photocoupling chemistry to afford FSNP-labeled glycan probes. Lectins were printed on epoxy slides in duplicate sets to generate lectin super-microarrays where multiple assays could be carried out simultaneously in each lectin microarray. Thus, the lectin super-microarray was treated with FSNP-labeled glycans to screen for specific binding pairs. Furthermore, a series of ligand competition assays were carried out on a single lectin super-microarray to generate the dose-response curve for each glycan-lectin pair, from which the apparent affinity constants were obtained. Results showed 4~7 orders of magnitude increase in affinity over the free glycans with the corresponding lectins. Thus, the glycan epitope structures having weaker affinity than the parent glycans could be readily identified and analyzed from the lectin super-microarrays.

Quantitative Fluorine NMR To Determine Carbohydrate Density on Glyconanomaterials Synthesized from Perfluorophenyl Azide-Functionalized Silica Nanoparticles by Click Reaction

“…The residual was then dissolved in methanol-d 4 together with methyl pentafluorobenzoate as the internal standard for 19 F NMR analysis. 19 …”

“…19 F NMR spectra of (A) PFPA-SNPs after treatment with aqueous HF, (B) PFPA-silane, (C) Man-SNPs after treatment with aqueous HF, (D) compound 7. Peak (F-4) from methyl pentafluorobenzoate standard is marked as "S".…”

Glyconanomaterials: Emerging applications in biomedical research

“…For the photoinitiated carbohydrate conjugation to SNPs, a method developed in our laboratory the nanoparticles were first functionalized with PFPA-silane, after which the carbohydrates were conjugated by irradiation in the presence of carbohydrates. Using this methodology we have for example prepared carbohydrate-functionalized SNPs from different mono- and oligosaccharides [15, 76, 122–124]. …”

“…The high specific surface area allows the nanomaterial to accommodate high-density carbohydrate ligands, enhancing carbohydrate-mediated interactions by way of multivalency. We [10–15] and others [16, 17] have thus shown that the affinities of glyconanomaterials with lectins are several orders of magnitude higher than those of free ligands. Furthermore, by conjugating epitopes of more complex glycans on nanoparticles, the affinities of the resulting nanomaterials could surpass those of the original oligosaccharide glycans [12, 18, 19].…”

Aggregation-based detection of M. smegmatis usingd-arabinose-functionalized fluorescent silica nanoparticles

“…FSNP was prepared by co-condensing tetraethyl orthosilicate with FITC-derivatized silane (Scheme 1a) 19, 20 to give particles of 30.4 ± 1.9 nm (TEM) or 38.6 ± 1.7 nm (DLS) (Fig. S1).…”