GPⅡb/Ⅲa抗体的二级结构及T、B细胞表位的预测

On Predicting the T Cell and B Cell Epitopes of Platelet Membrane Glycoprotein Ⅱb/Ⅲa Antibody from Human and Mice

应用SYFPEITHI等七种软件对人、鼠源血小板糖蛋白GPⅡb/Ⅲa抗体蛋白进行HLA-A*0201、HLA-A*1101和HLA-A*2401限制性表位预测,经去除已发表多肽,取前者覆盖后两者多肽为混合CTL表位;再联合predTAP等TAP结合预测软件结果及NetChop等蛋白酶切位点预测软件结果,取包含这两者的多肽为CTL修正表位。用基于肽MHC-Ⅱ结合算法Syfpeithi等软件进行HLA-DR Th表位预测,最后取Th表位覆盖CTL修正表位而得T细胞混合表位。用DNAstar软件子程序Protean软件对两条蛋白链进行二级结构、B细胞表位预测。从1 740条多肽中筛选出人源GPⅡb/Ⅲa抗体5条T细胞混合表位肽:1-15、24-38、50-64、65-81、109-121,7条B细胞表位肽:5-9、22-30、40-46、55-71、80-90、100-105、110-115;鼠源GPⅡb/Ⅲa抗体5条T细胞混合表位肽:1-15、26-40、46-60、68-82、93-107,5条B细胞表位肽:5-10、38-43、58-70、77-84、99-105。

HLA-A＊0201,HLA-A＊1101,and HLA-A＊2401 CTL restricted epitopes of platelet membrane glycoprotein Ⅱb/Ⅲa antibody of human and mice were predicted by use of SYFPEITHI,RANKPEP,BIMAS,SVMHC,PREDEP,MHCPRED,and PROPRED predictive programs.In the results,the peptides（found in HLAPRED） that can lead to autoimmune disease and have been published were removed;and the epitopes of HLA-A＊0201 must cover the epitopes of HLA-A＊1101 and HLA-A＊2401 being combined to predTAP and TAPPred for predicting the binding affinity of peptides toward the TAP transporter and NetChop,MAPPP,PAProc for predicting cleavages;HLA-DR Th restricted epitopes of GPⅡb/Ⅲa antibody were predicted by SYFPEITHI,RANKPEP,MHCPRED,and HLAPRED,after removal of the peptides（found in HLAPRED） that can lead to autoimmune disease and have been published,the Th epitopes must cover the CTL mixed epitopes as being stated above.The secondary structure,hydrophobic regions,flexibility,surface probability and the B cell epitope were predicted by using various methods.Ten mixed peptides of T cell epitopes were selected from more than 1 740 peptides.They were located at the aa9～1-15,aa24-38,aa50-64,aa65-81,aa109-121 of anti-GPⅡb/Ⅲa-Human and the aa1-15,aa26-40,aa46-60,aa68-82,aa93-107 of anti-GPⅡb/Ⅲa-Mice.B cell epitopes of anti-GPⅡb/Ⅲa-Human might locate at aa5-9,aa22-30,aa40-46,aa55-71,aa80-90,aa100-105,aa110-115;and the epitopes of anti-GPⅡb/Ⅲa-Human might locate at aa5-10,aa38-43,aa58-70,aa77-84,and aa99-105.