1. Selective association of a 22-38 kDa glycoprotein with MHC class II DP antigen on activated human lymphocytes at the plasma membrane.
- Author
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Carra G, Giunta M, Benati C, Bovolenta C, Tridente G, Libonati M, and Gerosa F
- Subjects
- B-Lymphocytes chemistry, B-Lymphocytes immunology, Cells, Cultured, Glycosylation, HLA-DP Antigens biosynthesis, HLA-DP Antigens isolation & purification, Humans, Interphase immunology, Lymphocyte Subsets chemistry, Membrane Glycoproteins biosynthesis, Membrane Glycoproteins isolation & purification, Molecular Weight, Protein Binding immunology, T-Lymphocytes chemistry, T-Lymphocytes immunology, HLA-DP Antigens metabolism, Lymphocyte Activation, Lymphocyte Subsets immunology, Membrane Glycoproteins metabolism
- Abstract
Two-dimensional electrophoretic analysis (2D-PAGE) of cell surface human DP and DR class II antigens identified a glycoprotein, designated pX, that is associated at the cell surface with DP but not DR class II antigen in activated T, B and NK lymphocytes but not in resting B lymphocytes, Raji B lymphoma cells, activated thymic epithelial cells or activated monocytes. pX is a heavily glycosylated protein with an apparent molecular mass spanning between 38 kDa and 22 kDa, that is reduced, after deglycosylation with Endo-F, to 22 kDa. The pX structure appears nonpolymorphic and independent of DP polymorphism, as suggested by 2D-PAGE migrational pattern of 125I-labelled Endo-F deglycosylated DP immunoprecipitates from T cells blasts derived from four donors with different DP allotypes. The apparent absence of polymorphism of pX is further suggested by two-dimensional peptide mapping of a single spot derived from 2D-PAGE of 125I-labelled DP deglycosylated immunoprecipitates from two donors.
- Published
- 1996
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