The structure of the oligosaccharides of α3β1 integrin from human ureter epithelium (HCV29) cell line

Abstract

There is a growing line of evidence that glycosylation of α and β subunits is important for the function of integrins. Integrin α3β1, from human ureter epithelium cell -line HCV29, was isolated by affinity chromatography on laminin GD6 peptide. Characterization of its carbohydrate moieties was carried out using sodium dodecyl sulfate/polyacrylamide gel electrophoresis followed by Western blotting on Immobilon P and on-blot deglycosylation with peptide N-glycosidase-F. Profiles of N-glycans for each subunit were obtained by matrix-assisted laser desorption/ionization mass spectrometry. Our findings demonstrated, in both subunits of integrin α3β1, the presence of complex type oligosaccharides with a wide heterogeneity. Bi-tri-and tetra-antennary structures were the most common, while high-mannose type structures were minor. Also the presence of short poly-N-acetyllactosamine entities was shown. These results show that while the predominant oligosaccharides of both subunits are identical, some slight differences between them do exist.