Isolation and partial characterization of a mucin-type glycoprotein from plasma membranes of human melanoma cells.
Plasma membranes were isolated from HM7 melanoma cells grown in the presence of [3H]glucosamine and Na2(35)SO4 or [3H]mannose and [14C]glucosamine. The labeled glycoconjugates were solubilized with 0.6 M lithium diiodosalicylate/0.5% Triton X-100. Fractionation of glycoconjugates by repeated chromatography on columns of Sepharose CL-6B and DEAE-Sepharose and by affinity chromatography on WGA-Sepharose yielded three radiochemically homogeneous glycoproteins. One of these having an apparent molecular weight of 100,000 was found to contain clusters of (AcNeu)1 or 2 leads to [Gal leads to GalNAc] linked O-glycosidically to the protein. One other glycoprotein contained both O-glycosidically and N-glycosidically-linked oligosaccharides, and the third contained only N-glycosidically-linked carbohydrates. Preliminary results indicate that the 100,000 molecular weight mucin-type glycoprotein is present in significantly reduced quantitites in cultured human fetal uveal melanocytes. Further, the bulk of the glycoproteins from the melanocytes were of lower molecular size compared to those from the melanoma cells.
D002460:Cell Line; D002462:Cell Membrane / Q000032:analysis; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005944:Glucosamine / Q000378:metabolism; D006023:Glycoproteins / Q000302:isolation & purification*; D006801:Humans; D008358:Mannose / Q000378:metabolism; D008545:Melanoma / Q000032:analysis*; D008970:Molecular Weight; D011247:Pregnancy
D006023:Glycoproteins; D005944:Glucosamine; D008358:Mannose