2型猪链球菌表面蛋白Sao的生物信息学分析及基因工程疫苗的设计

发布时间：2019-03-13 16:50

【摘要】：目的利用生物信息学方法分析Sao蛋白结构并预测B细胞抗原表位,筛选可用于疫苗设计的序列。方法以Sao蛋白的氨基酸序列为基础,利用Protparam工具分析蛋白基本理化性质,TMHMM预测跨膜区,PredictProtein在线分析蛋白二级结构,SWISS-MODEL软件模拟三级空间构象,DNASTAR分析亲(疏)水性、可塑性和表面可及性,综合使用在线ABCPred和BepiPred工具预测B细胞抗原表位,筛选能用于构建基因工程疫苗的蛋白序列。结果 Sao蛋白羧基端存在7个高度一致的重复序列以及1个LPVTG保守膜锚定基序,二级结构组分中无规卷曲比例高达74.21%,三级空间构象模拟结果与二级结构预测一致。蛋白的亲水区域、可塑性区域、表面可及性区域比例分别为76.21%、64.06%和75.04%。Sao存在多个线性抗原表位,经筛选得到两个可用于疫苗设计的蛋白序列,BLAST显示这两个序列为猪链球菌所特有,存在于2型猪链球菌9种不同的分离菌株中,同时也存在于猪链球菌致病性血清型1、2、1/2、3、7、9、14型中。结论 Sao蛋白为不稳定蛋白,亲水性强,筛选得到的两个蛋白序列抗原性强且高度保守,为猪链球菌特有序列,能够用于基因工程疫苗的构建。
[Abstract]:Aim to analyze the structure of Sao protein and predict the epitope of B cell antigen by bioinformatics method, so as to screen the sequence which can be used in vaccine design. Methods based on the amino acid sequence of the Sao protein, the basic physical and chemical properties of the protein were analyzed by Protparam, the transmembrane region was predicted by TMHMM, the secondary structure of the protein was analyzed by PredictProtein on-line, the three-stage conformation was simulated by SWISS-MODEL software, and the hydrophilicity (hydrophobicity) was analyzed by DNASTAR. The on-line ABCPred and BepiPred tools were used to predict B-cell epitopes and to screen the protein sequences which could be used to construct genetically engineered vaccines. Results there were 7 highly consistent repeat sequences and 1 LPVTG conservative membrane anchoring motif in the carboxyl terminal of Sao protein. The random crimping ratio of the secondary structural components was 74.21%. The results of tertiary spatial conformation simulation were consistent with the secondary structure prediction. The proportion of hydrophilic region, plastic region and surface accessible region of the protein were 76.21%, 64.06% and 75.04%.Sao respectively, and there were several linear epitopes. Two protein sequences which could be used in vaccine design were obtained by screening. BLAST showed that the two sequences were specific to Streptococcus suis. They were found in 9 different isolates of Streptococcus suis type 2 and in serotypes 1, 2, 1, 2, 3, 7, 9 and 14 of Streptococcus suis serotype 1, 2, 1, 2, 3, 7, 9, 14, respectively. Conclusion the Sao protein is an unstable protein with strong hydrophilicity. The two sequences are highly conserved and antigenicity. They are unique sequences of Streptococcus suis and can be used in the construction of genetic engineering vaccine.
【作者单位】：南京军区军事医学研究所;温州医科大学检验医学院生命科学学院;
【基金】：国家自然科学基金项目(No.81172794,81071317,31170124,81171527) 南京军区医学科技创新课题(ZX39) 江苏省自然科学基金项目(No.BK2011098,BK2011097) 浙江省大学生科技创新活动计划(新苗人才计划)资助项目(No.2013R413039)
【分类号】：R392.1

【参考文献】