title: Binding affinities of NKG2D and CD94 to sialyl Lewis X-expressing N-glycans and heparin.
abstract: Lectin-like receptors natural killer group 2D (NKG2D) and CD94 on natural killer (NK) cells bind to α2,3-NeuAc-containing N-glycans and heparin/heparan sulfate (HS). Using recombinant glutathione S-transferase-fused extracellular lectin-like domains of NKG2D (rGST-NKG2Dlec) and CD94 (rGST-CD94lec), we evaluated their binding affinities (K(d)) to high sialyl Lewis X (sLeX)-expressing transferrin secreted by HepG2 cells (HepTf) and heparin-conjugated bovine serum albumin (Heparin-BSA), using quartz crystal microbalance (QCM) and enzyme immunoassay (EIA) microplate methods. K(d) values obtained by linear reciprocal plots revealed good coincidence between the two methods. K(d) values of rGST-NKG2Dlec obtained by QCM and EIA, respectively, were 1.19 and 1.11 µM for heparin-BSA >0.30 and 0.20 µM for HepTf, while those of rGST-CD94lec were 1.31 and 1.45 µM for HepTf >0.37 and 0.36 µM for heparin-BSA. These results suggested that these glycans can interact with NKG2D and CD94 to modulate NK cell-dependent cytotoxicity.
authors.affiliation: Department of Clinical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Chiba 247–8510, Japan. koji@phar.toho-u.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Higai
authors.forename: Chiho
authors.initials: C
authors.lastname: Suzuki
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Imaizumi
authors.forename: Xin
authors.initials: X
authors.lastname: Xin
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Azuma
authors.forename: Kojiro
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D002460:Cell Line; D005786:Gene Expression Regulation / Q000502:physiology; D056945:Hep G2 Cells; D006493:Heparin / Q000737:chemistry*; D006801:Humans; D007124:Immunoenzyme Techniques; D051920:NK Cell Lectin-Like Receptor Subfamily D / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009844:Oligosaccharides / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D011485:Protein Binding; D000080506:Sialyl Lewis X Antigen
chemical_list: C497869:KLRD1 protein, human; C527085:KLRK1 protein, human; D051920:NK Cell Lectin-Like Receptor Subfamily D; D055655:NK Cell Lectin-Like Receptor Subfamily K; D009844:Oligosaccharides; D011134:Polysaccharides; D000080506:Sialyl Lewis X Antigen; D006493:Heparin