尤文肉瘤EWS-FLI1蛋白融合区的二级结构及B细胞表位的预测

Prediction for secondary structure and B cell epitopes of fusion region in EWS-FLI1 protein of Ewing's sarcoma

目的:预测尤文肉瘤EWS-FLI1蛋白融合区的二级结构及B细胞表位。方法:采用SOPM/SOPMA法、Chou-Fasman法和Karplus-Schulz法预测EWS-FLI1蛋白的二级结构;综合分析蛋白的柔性结构、亲水性、表面可及性与抗原性,通过预测数据再确定EWS-FLI1蛋白融合区的抗原表位。结果:EWS-FLI1蛋白的二级结构主要为柔性区域,位于EWS-FLI1蛋白N端5,23-30,32,36-49,62,69-100,118-123,128-132,135,137-170,173-179,183-271,276-286,291-301,317-319,328-331,346-353,396-400,407-408,426-438区段;α螺旋位于N端10-15,34,55,106-107,306-316,340-345,359-362,386-392区段;β折叠位于N端20,22,50-52,65-67,102-107,272,274,289-290,323,325-327,371-375,380-384,422-424,446-447区段;B细胞表位位于N端69-79,99-114,128-152,167-171,194-208,248-265,397-406区段,融合区B细胞表位位于N端248-265区段。结论:应用多参数预测EWS-FLI1蛋白融合区的二级结构与B细胞表位,为蛋白特征及复合表位疫苗的进一步研制奠定了基础。

Objective：To predict the secondary structure and B cell epitopes of fusion region in EWS-FLI1 protein of Ewing＇s sarcoma. Methods ：The secondary structure of EWS-FLI1 protein was predicted by SOPM/SOPMA, Chou-Fasman and Karplus-Schulz. Hydrophilicity, surface accessibility and antigenicity were aggregately analyzed and the possible B cell epitopes of fusion region of EWS- FLI1 protein on the basis of predicted data were determined. Results：The flexible regions dominated the secondary structure of EWS- FLI1 protein, locating at the N-terminal No. 5, 23-30, 32,36-49, 62,69-100,118-123,128-132,135,137-170,173-179,183-271, 276-286,291-301, 317-319,328-331,346-353, 396-400, 407-408,426-438 regions, or-helix regions occupied the N-terminal No. 10- 15,34,55,106-107,306-316,340-345,359-362,386-392 regions. And the N-terminal No. 20,22,50-52,65-67,102-107,272,274, 289-290,323,325-327,371-375,380-384,422-424,446-447 were the 13-sheet regions. B cell epitopes were probably located at the N- terminal No. 69-79,99-114,128-152,167-171,194-208,248-265,397-406 regions, and the the N-terminal No. 248-265 was the predicted epitope of fusion region. Conclusion： Aggregate prediction of the secondary structure and B cell epitope of fusion region of EWS- FLI1 protein lay the basis for of characteristic study of the protein and for development of multi-epitope based vaccine.