Identification and purification of 115- and 125-kilodalton cell surface human melanoma-associated antigens.
Surface macromolecules shed into culture medium by radioiodinated human melanoma cells were fractionated on Sepharose 6B and by sequential lectin-affinity chromatography. Radioactivity associated with melanoma-associated antigens (MAAs) was assayed by indirect immunoprecipitation with anti-melanoma serum. Two MAAs were separated and highly purified. Both antigens were single-chain glycoproteins expressed on many, but not all, melanoma cells but undetectable on normal melanocytes and a variety of unrelated normal, fetal, and malignant cells. One MAA, with a molecular mass of approximately 115 kd, eluted on Sepharose 6B in a lower molecular mass peak and had a high affinity for ricin lectin. The carbohydrate side chain of this antigen contained D-galactose. The other MAA, with a molecular mass of approximately 125 kd, eluted on Sepharose 6B in a peak of higher molecular mass and had a high affinity for wheat germ lectin. The carbohydrate side chain of this antigen contained sialic acid. Both antigens were highly purified. By sodium dodecyl sulfate-poly-acrylamide gel electrophoresis analysis, no contaminating proteins were present in the purified 115-kd MAA fraction, and only a single minor contaminant was present in the fraction containing the purified 125-kd MAA. These two antigens differed in their biochemical or immunological properties from other MAAs of similar size that have been previously described.
D000951:Antigens, Neoplasm / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis*; D002241:Carbohydrates / Q000032:analysis; D002846:Chromatography, Affinity; D002847:Chromatography, Agarose; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes; D006801:Humans; D037102:Lectins / Q000378:metabolism; D008545:Melanoma / Q000276:immunology*; D058950:Melanoma-Specific Antigens; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000032:analysis / Q000276:immunology / Q000302:isolation & purification*
D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D002241:Carbohydrates; D000939:Epitopes; D037102:Lectins; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins