中文摘要：

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。

英文摘要：

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.