Characterization of human vascular endothelial cadherin glycans.
The glycosylation pattern of human vascular endothelial cadherin (VE-cadherin), purified from cultured human umbilical cord vein endothelial cells, was analyzed. VE-cadherin was metabolically radiolabeled with d-[6-(3)H]glucosamine, isolated by immunoprecipitation, purified by SDS-PAGE and in-gel digested with endoproteinase Asp N. Oligosaccharides were sequentially released from resulting glycopeptides and analyzed by chromatographic profiling. The results revealed that VE-cadherin carries predominantly sialylated diantennary and hybrid-type glycans in addition to some triantennary and high mannose-type species. Highly branched, tetraantennary oligosaccharides were found in trace amounts only. Immunohistochemical labeling of VE-cadherin and sialic acids displayed a codistribution along the intercellular junctions in endothelial cells of human umbilical arteries, veins, and cultured endothelial monolayers. Ca(2+)-depletion, performed on cultured endothelial cells, resulted in a reversible complete disappearance of VE-cadherin and of almost all sialic acid staining from the junctions. Sialidase treatment of whole cells caused a change of VE-cadherin immunofluorescence from a continuous and netlike superstructural organization to a scattered inconsistent one. Hence, cell surface sialic acids might play a role in VE-cadherin organization.
Geyer
H
H
Institute of Biochemistry, Justus-Liebig-Universität Giessen, Friedrichstrasse 24, D-35392 Giessen, Germany.
Geyer
R
R
Odenthal-Schnittler
M
M
Schnittler
H J
HJ
D000199:Actins / Q000302:isolation & purification; D015703:Antigens, CD; D015820:Cadherins / Q000737:chemistry*; D002240:Carbohydrate Sequence; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D006801:Humans; D007365:Intercellular Junctions / Q000737:chemistry; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid / Q000302:isolation & purification; D009844:Oligosaccharides / Q000737:chemistry*; D014471:Umbilical Veins / Q000166:cytology; D000099152:Cadherin 5
D000199:Actins; D015703:Antigens, CD; D015820:Cadherins; D006023:Glycoproteins; D019158:N-Acetylneuraminic Acid; D009844:Oligosaccharides; D000099152:Cadherin 5