Solubilization of complexes between tumor-associated and H-2 antigens from a tumor cell plasma membrane.
The tumor-associated cell surface antigens (TAA) gp 71 and AgI cocap H-2, but are not associated with H-2 following solubilization of membrane with detergent. We have attempted to solubilize intact TAA/H-2 complexes from surface-labeled L cells using decreasing concentrations of the nonionic detergent Nonidet-P 40 (NP 40). Associations between gp 71 and H-2 and between AgI and H-2 in solution were detected using sequential immunoprecipitation. gp 71/H-2 and AgI/H-2 complexes were solubilized at the lowest detergent concentration used, 0.01% NP 40. No coprecipitation of these antigen pairs was seen at any higher NP 40 concentration tested. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed lthat precipitation of antigens solulbilized in 0.01% NP 40 leads to coprecipitation of a small number  of other protein peaks and does not appear to involve wholesale inclusion of labeled membrane proteins. These results, together with previous observations of cocapping between TAA and H-2 antigens, suggest that the molecules are associated with one another in the membrane. Detergent solubilization of membranes with all but the most gentle conditions leads to disruption of these complexes.
D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology*; D000954:Antigens, Surface; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D006183:H-2 Antigens / Q000276:immunology*; D007152:Immunologic Capping; D007739:L Cells / Q000276:immunology; D051379:Mice; D009374:Neoplasms, Experimental / Q000473:pathology; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000494:pharmacology; D011817:Rabbits; D012967:Sodium Dodecyl Sulfate; D013724:Teratoma / Q000473:pathology
D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D006183:H-2 Antigens; D012967:Sodium Dodecyl Sulfate; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40