摘要
目的对肠出血性大肠埃希菌O157：H7紧密黏附素C300与黏膜佐剂不耐热肠毒素（LTB）融合蛋白二级结构及B细胞识别表位进行预测,为开发新型疫苗提供理论依据.方法采用DNA star软件中的Protean预测软件对Intim in C300与LTB融合蛋白的亲水性指数、β-转角、柔韧性、表面可及性和抗原指数进行预测.结果在融合蛋白N端第1-10、20-30、110-120、210-220、300-310、350-360、380-390和415-420区段可能是α-螺旋中心,在N端第195-205、300-320、335-350和390-410区段形成4个大的β-折叠中心区域,在各β-折叠区间存在均匀且较丰富的转角区域.融合蛋白的蛋白柔性区域可能位于N端第20-35、52-65、75-85、105-115、150-160、172-188、260-275和372-388区域,这些区域有一定幅度的折叠或摆动,可形成较复杂的三级结构.亲水性区域位于第50-60、70-80、155-165、190-200、240-250、260-270、330-340和375-385区段,这8个区域作为抗原表位可能性大.结论通过生物信息学技术分析,可有效地预测融合蛋白二级结构和B细胞表位,为人工合成优势肽段进行肠出血性大肠埃希菌O157：H7的重组疫苗研制提供理论依据.
Objective To predict the secondary structure and B cell epitopes for the fusion protein of Intimin C300 and LTB in EHEC O157：H7 to provide some evidences for developing a new type of the vaccine.Method The secondary structure of Intimin C300 and LTB was predicted by the methods of Garnier-Robson,Chou-Fasman and Karplus-Schplus,and hydrophilicity,surface probability and antigenic index were obtained by the methods of Hopp-Woods,Emini and Jameson-wolf respectively.Meanwhile,the B cell epitopes for fusion protein of Intimin C300 and LTB were predicted according to these methods.Results There is likely some centers of α-helix in the fusion protein＇s N-terminal No.1-10,20-30,110-120,210-220,300-310,350-360,380-390 and 415-420.And there are four central regions of β-sheet in the fusion protein＇s N-terminal No.195-205,300-320,335-350,390-410.In the each of β-sheet regions,turn regions existed equably and prolifically.Furthermore,the terminal No.20-35,52-65,75-85,105-115,150-160,172-188,260-275 and 372-388 may be the flexible regions of the fusion protein,whose regions will be folding and wobbling in a certain range and possibly become more complicated tertiary structure.The terminal No.50-60,70-80,155-165,190-200,240-250,260-270,330-340 and 375-385 belonged to Hydrophilia regions.The B-cell epitopes possibly localized in or nearby these eight regions.Conclusion This study would be helpful for predetermination of the protein＇s secondary structure and B cell epitopes,and provide theory evidence for developing a new type of genetic vaccine against EHEC O157：H7 by using the synthetic peptide approach through the bioinformatics technology.
出处
《北华大学学报（自然科学版）》
CAS
2011年第3期296-299,共4页
Journal of Beihua University（Natural Science）
基金
吉林省科技发展计划项目(20080513)
