Chochola, J ; Fabre, C ; Bellan, C ; Luis, J ; Bourgerie, S ; Abadie, B ; Champion, S ; Marvaldi, J ; Elbattari, A
Journal of Biological Chemistry 268 (4) 2312-2318
publié le , mis à jour le
The vasoactive intestinal peptide (VIP) receptor from the human melanoma cell line IGR39 has been shown to be a 60-kDa glycoprotein. Using serial lectin affinity chromatography, as well as specific glycosidases, we demonstrate that VIP receptor-linked carbohydrates are predominantly tri- or tetraantennary sialylated N-linked oligosaccharides, 27% of which are fucosylated, and some may have terminal galactose residues. Treatment of I-125-VIP receptor complexes with peptide-N-(N-acetyl-beta-D-glucosaminyl)asparagine amidase revealed the presence of at least three N-linked carbohydrate chains/receptor polypeptide. To investigate the functional role of the carbohydrate moiety, I-125-VIP binding to IGR39 cell membranes was tested in the presence of soluble lectins. Among the lectins tested, only wheat germ agglutinin (WGA) was found to markedly inhibit VIP binding in a dose-dependent manner.