title: The biochemical characterization of a cell surface antigen associated with acute lymphoblastic leukemia and lymphocyte precursors.
abstract: The acute lymphoblastic leukemia- (ALL) associated membrane antigen is a single glycosylated polypeptide of approximate m.w. of 100,000 (gp100), containing no intrachain disulfide linkages. Approximately 50% of gp100 will bind to lentil lectin, whereas 100% will bind to the lectin from Ricinus communis. Both lentil-binding and lentil nonbinding forms of the antigen appear to be identical by 2-dimensional isoelectric focusing/SDS polyacrylamide gel electrophoresis and peptide mapping. Carbohydrate, although contributing approximately 20 to 25% of the m.w., appears not to be involved in the antigenic site of the ALL antigen as judged by precipitation of a molecule after tunicamycin treatment of cells or glycosidase digestion. Charge shift electrophoresis and labeling with the lipophilic nitrene reagent hexanoyl diiodo-N-(4-azido-2-nitrophenyl)-tyramine suggests that the cALL antigen is probably not an integral membrane protein; however, it remains tightly bound to the plasma membrane after subcellular fractionation. A glycoprotein of the same m.w. has been detected by immunoprecipitation on bone marrow cells of nonleukemic patients. serologic studies indicate that the cALL-associated antigen is found on the terminal transferase-positive lymphoid cells, and it therefore seems likely that the gp100 molecule is a normal gene products of lymphocyte precursors.
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000276:immunology*; D002454:Cell Differentiation; D055598:Chemical Phenomena; D002621:Chemistry; D002918:Chymotrypsin / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes; D006023:Glycoproteins / Q000276:immunology; D007525:Isoelectric Focusing; D037102:Lectins / Q000494:pharmacology; D007945:Leukemia, Lymphoid / Q000276:immunology*; D008214:Lymphocytes / Q000166:cytology*; D008970:Molecular Weight; D010455:Peptides / Q000276:immunology; D011817:Rabbits; D014357:Trypsin / Q000494:pharmacology
chemical_list: D000954:Antigens, Surface; D000939:Epitopes; D006023:Glycoproteins; D037102:Lectins; D010455:Peptides; D002918:Chymotrypsin; D014357:Trypsin