Akademik Veri Yönetim Sistemi
OPEN LIFE SCIENCES, cilt.20, sa.1, 2025 (SCI-Expanded, Scopus)
Sialic acids (SAs) are terminal monosaccharides on cell surfaces, mediating diverse signaling events through recognition by carbohydrate-binding proteins, lectins. Lectins recognize glycans and regulate molecular interactions. Altered lectin-SA interactions are associated with diseases, highlighting the need for accessible analytical tools to study these interactions. We explored the use of SA-conjugated quantum dots (SA-QDs) as direct fluorescent probes for lectin detection in an ELISA-based format. SA-QDs were synthesized via EDC-mediated conjugation of Neu5Ac alpha(2-6)Gal beta(1-4)GlcNAc-beta-ethylamine to carboxylated QDs. Ethanolamine-capped QDs (EC-QDs) served as negative control probes. Characterization by FTIR confirmed amide bond formation; zeta potential measurements showed an increased negative charge upon functionalization (QDs: -23.1 mV; SA-QDs: -34.0 mV), and SEM revealed an increase in particle size. In a 96-well assay, SA-QDs exhibited higher fluorescence retention on alpha(2-6)-specific lectins (Siglec-2 and SNA) compared to negative control BSA, non-lectin glycolipid control fetuin and a low-specificity control, Siglec-1. EC-QDs showed no specific retention, validating assay specificity. Furthermore, fluorescence data correlated between imaging and spectrofluorometric analyses (r2 = 0.94). This proof-of-concept study, for the first time, demonstrates the potential of SA-QDs as novel lectin-recognition probes capable of distinguishing specific from non-specific sugar-lectin interactions, though the current system requires further optimization to achieve quantitative sensitivity.