title: Direct binding of a soluble natural killer cell inhibitory receptor to a soluble human leukocyte antigen-Cw4 class I major histocompatibility complex molecule.
abstract: Natural killer (NK) cells expressing specific p58 NK receptors are inhibited from lysing target cells that express human leukocyte antigen (HLA)-C class I major histocompatibility complex molecules. To investigate the interaction between p58 NK receptors and HLA-Cw4, the extracellular domain of the p58 NK receptor specific for HLA-Cw4 was overexpressed in Escherichia coli and refolded from purified inclusion bodies. The refolded NK receptor is a monomer in solution. It interacts specifically with HLA-Cw4, blocking the binding of a p58-Ig fusion protein to HLA-Cw4-expressing cells, but does not block the binding of a p58-Ig fusion protein specific for HLA-Cw3 to HLA-Cw3-expressing cells. The bacterially expressed extracellular domain of HLA-Cw4 heavy chain and beta2-microglobulin were refolded in the presence of a HLA-Cw4-specific peptide. Direct binding between the soluble p58 NK receptor and the soluble HLA-Cw4-peptide complex was observed by native gel electrophoresis. Titration binding assays show that soluble monomeric receptor forms a 1:1 complex with HLA-Cw4, independent of the presence of Zn2+. The formation of complexes between soluble, recombinant molecules indicates that HLA-Cw4 is sufficient for specific ligation by the NK receptor and that neither glycoprotein requires carbohydrate for the interaction.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Q R
authors.initials: QR
authors.lastname: Fan
authors.forename: D N
authors.initials: DN
authors.lastname: Garboczi
authors.forename: C C
authors.initials: CC
authors.lastname: Winter
authors.forename: N
authors.initials: N
authors.lastname: Wagtmann
authors.forename: E O
authors.initials: EO
authors.lastname: Long
authors.forename: D C
authors.initials: DC
authors.lastname: Wiley
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002850:Chromatography, Gel; D017931:DNA Primers; D015236:HLA-C Antigens / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D002479:Inclusion Bodies / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D021382:Protein Sorting Signals / Q000096:biosynthesis; D011971:Receptors, Immunologic / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism; D054340:Receptors, KIR; D054344:Receptors, KIR2DL3; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000096:biosynthesis / Q000276:immunology
chemical_list: D017931:DNA Primers; D015236:HLA-C Antigens; C039966:HLA-C*04 antigen; C515078:KIR2DL3 protein, human; D046911:Macromolecular Substances; D021382:Protein Sorting Signals; D011971:Receptors, Immunologic; D054340:Receptors, KIR; D054344:Receptors, KIR2DL3; D011993:Recombinant Fusion Proteins; D001613:beta 2-Microglobulin