Binding Affinities of NKG2D and CD94 to Sialyl Lewis X-Expressing N-Glycans and Heparin
Binding Affinities of NKG2D and CD94 to Sialyl Lewis X-Expressing N-Glycans and Heparin
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DOI：
10.1248/bpb.34.8
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发表时间：
2011-01-01
影响因子：
2
通讯作者：
Matsumoto, Kojiro
中科院分区：
文献类型：
--
作者：
Higai, Koji;Suzuki, Chiho;Matsumoto, Kojiro
自然杀伤（NK）细胞上的凝集素样受体自然杀伤组2D（NKG 2D）和CD 94与含α 2，3-NeuAc的N-聚糖和肝素/硫酸乙酰肝素（HS）结合。使用重组谷胱甘肽S-转移酶融合的NKG 2D（rGST-NKG 2Dlec）和CD 94（rGST-CD 94 lec）的胞外凝集素样结构域，我们使用石英晶体微天平（QCM）和酶免疫测定（EIA）微板方法评估了它们与HepG 2细胞（HepTf）分泌的高唾液酸刘易斯X（sLeX）表达转铁蛋白（sLeX）和肝素结合牛血清白蛋白（Heparin-BSA）的结合亲和力（Kd）。用线性倒数作图法测得的K-d值表明两种方法具有较好的一致性。通过QCM和EIA获得的rGST-NKG 2Dlec的Kd值分别为1.19和1.11 μ M，对于肝素-BSA>0.30和0.20 μ M，对于HepTf，而rGST-CD 94 lec的Kd值分别为1.31和1.45 μ M，对于HepTf >0.37和0.36 μ M，对于肝素-BSA。这些结果表明，这些聚糖可以与NKG 2D和CD 94相互作用，以调节NK细胞依赖性细胞毒性。
Lectin-like receptors natural killer group 2D (NKG2D) and CD94 on natural killer (NK) cells bind to alpha 2,3-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 mu M for heparin-BSA >0.30 and 0.20 mu M for HepTf, while those of rGST-CD94lec were 1.31 and 1.45 mu M for HepTf >0.37 and 0.36 mu M for heparin-BSA. These results suggested that these glycans can interact with NKG2D and CD94 to modulate NK cell-dependent cytotoxicity.