人Izumo蛋白的二级结构及B细胞抗原表位预测

目的:预测人Izumo蛋白的二级结构及B细胞抗原表位.方法:以人Izumo基因序列为基础,按Chou-Fasman和Gamier-Robson方法预测其编码蛋白的二级结构,采用Karplus-Schulz方法预测Izumo蛋白骨架区的柔韧性;按Kyte-Doolittle方法预测其亲水性、Emini方法预测蛋白质表面可能性及Jameson-Wolf方法预测抗原性指数.结果:Chou-Fasman及Gamier-Robson两种方法预测的结果均表明,Izumo蛋白含较多的α螺旋,蛋白第6～17、30～40、88～99、103～120、153～160、173～188、249～260、283～297、334～338和339～346区段可能是α螺旋中心,第21～25、198～200、245～248和320～323区段可能是β折叠中心.用Kyte-Doolittle、Emini和Jameson-wolf方法分别对Izumo蛋白B细胞抗原表位进行预测结果表明,蛋白质第36～42、62～66、94～99、118～122、129～132、151～154、161～164、173～177、205～208、212～216、256～265、271～276、283～288、314～318和336～350区段附近很可能为B细胞表位优势区域.结论:该研究结果有助于确定Izumo蛋白的B细胞优势表位及发挥免疫避孕的活性部位.

Prediction of the secondary structure and B cell epitopes for the Izumo protein of Homo Sapiens

Objective:To predict and analyze the secondary structure and B cell epitopes of Izumo protein.Methods: The secondary structure and flexible regions of Izumo protein were predicted by the methods of Chou-Fasman,Gamier-Robson and Karplus-Schulz.Moreover,hydrophilicity plot,surface probability plot and antigenic index of Izumo protein were predicted by the methods of Kyte-Doolitde,Emini and Jameson-Wolf,respectively.Results: Izumo protein contained moreαhelix regions.There were several centers ofαhelix in the regions of 6-17,30-40,88-99,103-120,153-160,173-188,249-260,283-297,334-338 and 339-346 of Izumo protein,and several centers of βsheet in the regions of 21-25,198-200,245-248 and 320-323.Moreover,many distinct B cell epitopes in Izumo protein possibly localized in the regions of 3642,62-66,94-99,118-122,129-132,151-154,161-164,173-177,205-208,212-216,256-265,271-276,283-288,314-318 and 336-350.Conclusion:These results are helpful for identification of the dominant B cell epitopes and the functional domains of Izumo protein.