An Arg-Gly-Asp-directed receptor on the surface of human melanoma cells exists in an divalent cation-dependent functional complex with the disialoganglioside GD2.

摘要: The disialogangliosides GD2 and GD3 play a major role in the ability of human melanoma cells to attach Arg-Gly-Asp-containing substrates such as fibronectin vitronectin, since pretreatment these with monoclonal antibodies oligosaccharide can inhibit their attachment spreading on adhesive proteins. This report demonstrates that (M21) synthesize express glycoprotein receptor shares antigenic epitopes vitronectin fibroblasts is capable specifically recognizing Gly-Arg-Gly-Asp-Ser-Pro sequence. In presence calcium, GD2, ganglioside M21 cells, colocalized this surface focal adhesion plaques demonstrated by double-label transmission immunoelectron microscopy indirect immunofluorescence. Biochemical evidence presented indicating contains associated calcium GD2. copurified for affinity columns containing either an peptide, concanavalin A, or lentil lectin. Arg-Gly-Asp-directed could be metabolically labeled 45Ca2+. Chelation ion EDTA caused dissociation from rendered remaining incapable binding peptide. Reconstitution experiments requirement not magnesium, Arg-Gly-Asp indicated addition enhance interaction.