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目的利用生物信息学技术对细粒棘球绦虫的延伸因子1(EF-1)进行分析,探讨其诊断价值。方法通过Expasy系统预测EF-1的理化性质,使用DNAStar软件分析蛋白亲水性、柔性区域、抗原指数及表面可及性,利用ABCpred与IEDB软件综合预测B细胞线性抗原表位,通过DNAStar软件预测T细胞表位,使用SOPMA软件预测二级结构,SWISS-MODEL网站构建EF-1的三级结构,使用MEGA软件选择neighbor joining法构建EF-1氨基酸序列的系统发育树。结果 EF-1基因序列全长1 412 bp,含有2个内含子;EF-1亲水性得分较高的区域为35~45、52~70、126~140、158~183、301~322、357~380、424~448;柔性区域为26~45、54~71、162~176、300~318、357~381、432~448;抗原性指数得分较高的区域分布与柔性区域一致;表面可及性得分较高的区域较少,主要分布在39~54、62~76、128~132、161~170、220~234、315~329、354~372、424~448;可能的B细胞线性表位的氨基酸序列为120~130、286~295、306~320、365~378;可能的优势性T细胞表位区域为34~48、164~177、222~244、280~290、321~330、396~407;EF-1的二级结构中α螺旋占32.81%、β折叠占22.54%、β转角占10.94%、无规则卷曲占33.71%;系统发育树结果表明多房棘球绦虫为一枝,其余聚于一枝,且内部形成许多梳齿状分枝。结论得到4个可能形成B细胞表位的区域、6个优势性T细胞表位区域,EF-1具有较高的保守性,可作为免疫诊断和药物治疗靶点。
Objective To investigate the diagnostic value of the extended factor 1 (EF-1) of Echinococcus granulosus by using bioinformatics techniques. Methods The physical and chemical properties of EF-1 were predicted by Expasy system. The protein hydrophilicity, flexible region, antigenic index and surface accessibility were analyzed by DNAStar software. The linear epitopes of B cells were predicted by ABCpred and IEDB software. DNAStar software was used to predict the EF- T-cell epitopes. Secondary structure was predicted by SOPMA software. The tertiary structure of EF-1 was constructed by SWISS-MODEL. The phylogenetic tree of EF-1 amino acid sequence was constructed by using MEGA software. Results The EF-1 gene sequence was 1 412 bp in length and contained two introns. The EF-1 region with high hydrophilicity score was 35-45, 52-70, 126-140, 158-183, 301-322 , 357 ~ 380,424 ~ 448 respectively; the flexible area was 26 ~ 45,54 ~ 71,162 ~ 176,300 ~ 318,357 ~ 381,432 ~ 448; the area with higher antigenic index score was consistent with the flexible area; The areas with higher surface accessibility score are less, mainly distributed in 39 ~ 54,62 ~ 76,128 ~ 132,161 ~ 170,220 ~ 234,315 ~ 329,354 ~ 372,424 ~ 448; the possible B The amino acid sequences of the linear epitopes of cells are 120-130, 286-29 5, 306-320, 365-378; possible predominant T cell epitope regions are 34-48,164-177,222-244,280-290, 321 ~ 330, 396 ~ 407. The secondary structure of EF-1 accounted for 32.81% of α-helix, β-sheet accounted for 22.54%, β-angle accounted for 10.94% and random coil accounted for 33.71% Tapeworm as a branch, the rest gathered in a branch, and the formation of many internal comb-shaped branches. CONCLUSIONS: Four regions that may form B cell epitopes and six dominant T cell epitope regions are obtained. EF-1 is highly conserved and can be used as a target for immunodiagnosis and drug therapy.