title: Further characterization of a melanoma-specific protein from human urine.
abstract: Isolation of a melanoma-specific protein (MSP) from human urine has been achieved using antibody affinity chromatography. MSP migrates as a single homogeneous protein on SDS PAGE and comparison of these data and ultracentrifuge analyses indicates that MSP contains a single polypeptide chain. MSP, however, shows considerable charge heterogeneity on isoelectric focusing. The desialo form, alpha 2 MSP, is found predominantly in patients with advanced metastatic disease, whilst only the sialo form alpha 1 MSP, is obtained from the urine of patients with early-stage disease. MSP does not react with antisera raised to alpha 1 foetoprotein (AFP) or carcinoembryonic antigen (CEA) and hence is immunologically distinct from these other tumour-associated glycoproteins. Antisera raised to MSP do not react with normal skin melanocytes nor with any foetal tissue tested, and hence the origin of MSP remains unresolved.
mesh_terms: D000918:Antibody Specificity; D000951:Antigens, Neoplasm / Q000302:isolation & purification / Q000652:urine*; D002272:Carcinoembryonic Antigen / Q000276:immunology; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007525:Isoelectric Focusing; D008545:Melanoma / Q000276:immunology* / Q000652:urine; D058950:Melanoma-Specific Antigens; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000652:urine*; D012795:Sialoglycoproteins / Q000302:isolation & purification / Q000652:urine*; D000509:alpha-Fetoproteins / Q000276:immunology
chemical_list: D000951:Antigens, Neoplasm; D002272:Carcinoembryonic Antigen; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D012795:Sialoglycoproteins; D000509:alpha-Fetoproteins