title: The 33,000 protein precipitated by Ly-6A.2-specific antibodies is not associated with the Ly-6 polymorphism.
abstract: In this study, the relative mass of the Ly-6A.2 antigen was shown to be 12,000-14,000, in contrast to initial studies which showed the relative mass to be 33,000. Using polymorphic Ly-6-specific antibodies, the 33,000 molecules could be immunoprecipitated from surface-iodinated thymocytes of Ly-6A.2+, Ly-6A.2- strains and a Ly-6A.2- mutant cell line BW(Thy-1-e). This clearly demonstrated that 33,000 molecules were not associated with the Ly-6 polymorphism. By contrast, when biosynthetically labeled Ly-6A.2+ spleen cell lysates were analyzed, the major species immunoprecipitated by the polymorphic Ly-6A.2-specific antibody was 12,000-14,000, although a minor 33,000 species were also evident. The Ly-6A-specific antibody D7 which detects a monomorphic epitope on the Ly-6A molecule could immunoprecipitate the 12,000-14,000 molecules from surface-labeled cells. By contrast, the Ly-6A.2-specific antibodies detecting the polymorphic Ly-6A.2 determinant could not, though the reasons for this difference are not clear. Thus 12,000-14,000 molecules were only immunoprecipitated from Ly-6A.2+ cells, whereas 33,000 molecules were precipitated from both Ly-6A.2+ cells and Ly-6A.2- cells. These findings suggest that the 33,000 molecules immunoprecipitated by 5041-24.2 are most likely to be an unrelated protein, possibly cross-reactive with some Ly-6A.2 antibodies.
authors.affiliation: Department of Pathology, University of Melbourne, Victoria, Australia.
authors.forename: B A
authors.initials: BA
authors.lastname: Houlden
authors.forename: I F
authors.initials: IF
authors.lastname: McKenzie
authors.forename: P M
authors.initials: PM
authors.lastname: Hogarth
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D000950:Antigens, Ly / Q000172:deficiency / Q000235:genetics* / Q000302:isolation & purification; D002458:Cell Fractionation; D002460:Cell Line; D007518:Isoantibodies; D008223:Lymphoma / Q000235:genetics; D051379:Mice; D008805:Mice, Inbred A; D008806:Mice, Inbred AKR; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008970:Molecular Weight; D011110:Polymorphism, Genetic; D011233:Precipitin Tests
chemical_list: D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D007518:Isoantibodies; C029805:Lyt antibodies