Native and asialo-Tamm-Horsfall glycoproteins as important ligands for the detection of GalNAcβ1 → and Galβ1 → 4GlcNAc active lectins

The binding properties of human Tamm-Horsfall Sd (a+) urinary glycoprotein (THGP) and asialo-THGP with various applied lectins was investigated by quantitative precipitin and precipitin inhibition assays. Both glycoproteins completely precipitated Abrus precatorius agglutinin (APA). They also reacted well with Wistaria floribunda (WFA), Glycine max (soybean, SBA), and Ricinus communis agglutinins and precipitated over 78% of the lectin nitrogen added, but reacted poorly or weakly with all α-anomeric GalNAc specific lectins, such as Helix pomatia (HPA), Phaseolus lunatus (lima bean, LBL), and Maclura pomifera (MPL) lectins. The glycoprotein-lectin interaction was inhibited by GaLNAcβ1 →, Galβ1 → 4GlcNAc, or by both. The findings suggest that Sd (a+) THGP and asialo-THGP are among the best water-soluble glycoprotein ligands for GalNAcβ1 → and Galβ1 → 4GlcNAc active lectins.