title: Uniquely conformed peptide-containing beta 2-microglobulin-free heavy chains of HLA-B2705 on the cell surface.
abstract: The human class I MHC molecules are known to generally exist on the cell surface either as peptide-containing complexes of H chain (alpha-chain) and beta(2)-microglobulin (beta(2)m) or as beta(2)m-free H chains incapable of binding peptides. In this study, a uniquely conformed peptide-containing beta(2)m-free HLA-B2705 H chain has been isolated using the recently described highly efficient perfusion-affinity chromatography system for purification of class I MHC protein molecules. This form recognized by the mAb MARB4 is very closely associated with the remainder of the peptide containing HLA-B2705/beta(2)m complex reactive with mAb ME1 and is present to approximately 1-10% of mAb ME1 reactive forms on the cell surface. Also, HLA-B2705 purified using the mAb ME1 affinity column includes this unique mAb MARB4-reactive, unusually stable peptide-containing beta(2)m-free form. A peptide nonamer GRWRGWYTY was isolated and identified from this beta(2)m-free HLA-B2705 H chain and was used to assemble the mAb MARB4 reactive form efficiently on the surface of cells expressing HLA-B2705. The discovery of this form opens new avenues for further investigation of the role of HLA-B27 in spondyloarthropathies.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, MA 02138, USA.
authors.forename: Pratap
authors.initials: P
authors.lastname: Malik
authors.forename: Polina
authors.initials: P
authors.lastname: Klimovitsky
authors.forename: Lih-Wen
authors.initials: LW
authors.lastname: Deng
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Boyson
authors.forename: Jack L
authors.initials: JL
authors.lastname: Strominger
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism; D000937:Antigen-Antibody Reactions; D001666:Binding Sites, Antibody; D001667:Binding, Competitive / Q000276:immunology; D002460:Cell Line; D002461:Cell Line, Transformed; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002846:Chromatography, Affinity; D000939:Epitopes / Q000378:metabolism; D015796:HLA-B27 Antigen / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism*; D006801:Humans; D009842:Oligopeptides / Q000302:isolation & purification* / Q000378:metabolism*; D010446:Peptide Fragments / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding / Q000276:immunology; D011487:Protein Conformation; D014162:Transfection; D001613:beta 2-Microglobulin / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D015796:HLA-B27 Antigen; D009842:Oligopeptides; D010446:Peptide Fragments; D001613:beta 2-Microglobulin