摘要：Killer lectin-like receptors on natural killer (NK) cells mediate cytotoxicity through glycans on target cells. We prepared recombinant glutathione S -transferase-fused extracellular lectin-like domains (AA 94-231) of natural killer group 2A (NKG2A) (rGST-NKG2A) and NKG2C (rGST-NKG2C) and determined the binding of these receptors to plates coated with heparin-conjugated bovine serum albumin (heparin-BSA) and glycoproteins. rGST-NKG2A and rGST-NKG2C directly bound to heparin-BSA with K d values of 20 and 40 n M , respectively. Binding of rGST-NKG2A and rGST-NKG2C to heparin-BSA was suppressed in the presence of soluble heparin, heparan sulfate, fucoidan, λ-carrageenan, and dextran sulfate. 2- O -Sulfate residues in heparin were essential for the binding of rGST-NKG2A and rGST-NKG2C. Moreover, rGST-NKG2A and rGST-NKG2C bound to multimeric sialyl Lewis X expressing transferrin secreted by HepG2 cells with K d values of 80 and 114 n M , respectively. This is the first report showing that NKG2A and NKG2C bind to heparin and α2,3-NeuAc-containing glycoproteins.
关键词：natural killer group 2A;natural killer group 2C;heparin;natural killer cell;sialyl Lewis X;binding affinity
