基于蛋白重复序列及线性B细胞表位预测筛选间日疟原虫特异性抗原肽

目的 目的 建立一种基于蛋白重复序列及线性B细胞表位预测筛选间日疟原虫 （Plasmodium vivax，P. vivax） 特异性抗原肽的方法。方法 方法 以PlasmoDB数据为基础， 建立间日疟原虫蛋白序列数据库。编写重复序列查找软件， 逐一检索16 aa多肽在全部蛋白序列中的重复次数， 统计出重复较高者进行连续B细胞表位预测， 优选具有间日疟原虫特异性的肽进行合成， 偶联钥孔戚血蓝蛋白 （Keyhole limpet hemocyanin， KLH） 后免疫小鼠， 并检测抗体滴度。 结果 结果 通过软件分析间日疟原虫全部5 432个蛋白序列中的16肽的重复次数， 利用BcePred网站预测其中重复较高的1 000个序列， 获得22个候选肽， 经聚类分析和相似性比较， 优选到5个潜在特异性肽， 人工合成并偶联KLH后免疫小鼠诱生的抗体滴度均超过1 : 9 000。 结 结论 论 建立了一种基于蛋白重复序列联合线性B细胞表位预测筛选间日疟原虫特异性抗原肽的方法， 得到的5个肽均能诱导小鼠产生高滴度抗体。

Plasmodium vivax specific peptides prediction and screening based on repetitive protein sequences and linear B cell epitope

Objective To establish a method based on repetitive protein sequences and linear B cell epitope to predict and screen specific peptides of Plasmodium vivax. Methods A P. vivax protein sequence database was reconstructed based on Plas-moDB data,and a customized software for searching of repetitive sequences was used to count the repetition times of each 16 aa peptide in the whole database,and the highly repetitive peptides were chosen to predict the potential linear B cell epitopes. The re-petitive peptides with P. vivax specificity were selected as candidate antigen peptides to synthesize and to couple with KLH carrier protein for immunizing BALB/c mice. After the immunization,the antibody titers of the immunized mice were detected. Results The repetitive information of 16 aa peptides was analyzed by screening of the total 5 432 peptide sequences in the P. vivax data-base. A total of 22 peptides were identified as candidate peptides from the top 1 000 repetitive peptides by linear B cell epitope pre-diction on the BcePred website. Through clustering analysis and similarity comparison,five potential P. vivax specific peptides were selected,synthesized and then coupled with KLH to immunize the mice. The antibody titers of the immunized mice induced by the 5 peptides were all above 1：9 000. Conclusion The method for predicting and screening of specific peptides of P. vivax based on repetitive protein sequences and linear B cell epitope has been established successfully,and all the 5 peptides obtained by the method can induce the high titer antibody in mice.