恶性疟原虫MAL13P1．129基因的抗原表位预测及免疫学分析

Epitopes prediction and inununo-analysis of MAL13P1.129 gene of Plasmodium falciparum

目的对恶性疟原虫MAL13P1．129基因的抗原表位进行预测，表达其重组蛋白并进行免疫学鉴定。方法利用生物信息学分析方法对MAL13P1．129基因的线性抗原表位进行预测，从亲水性、表面可及性、柔韧性及二级结构等方面对抗原表位进行筛选。人工合成经密码子优化的MAL13P1．129基因，构建至PET32a（＋）表达载体，获得PET32a129表达质粒，热激转化至宿主菌Rosettagami（DE3）中进行诱导表达，分别用抗His-标记的IgG及恶性疟患者的血清作Western印迹分析鉴定表达产物。结果MAL13P1．129基因具有2个潜在的抗原表位，分别位于氨基酸44～51、98～106。表达获得的重组蛋白与His-标记的IgG进行Western印迹有反应条带，与恶性疟患者血清无反应条带。结论MAL13P1．129蛋白具有2个抗原表位，其在大肠埃希菌中表达的重组蛋白能被His-标记的IgG识别，但不能被恶性疟患者血清识别。

Objective To predict the epitopes of MAL13P1. 129 gene of Plasmodiumfalciparum, to express its recombinant protein for immuno-analysis. Methods Linear epitope, hydrophilieity, flexibility, surface accessibility and secondary structure of MAL13P1. 129 protein sequence were predicted by bioinformatic approaches. The MAL13P1. 129 gene with codes modified to Escherichia coli was synthesized and then inserted into PET32a（＋） to construct expressing plasmid PET32a129. Rosetta gami （DE3） was transformed with PET32a129 and used for expression of recombinant MAL13P1. 129 protein. SDS-PAGE and Western blot were applied to detect the expressed protein. Results Two epitopes which located at 44-51aa, 98-106 aa were predicted in MAL13P1. 129 protein sequence. The recombinant protein expressed in Rosetta gami was able to hybridize with anti-His IgG but not with serum of patient infected with P. falciparurn. Conclusion The MAL13P1. 129 protein expressed in Rosetta gami with two epitopes predicted can be recognized by anti-His IgG but not by serum of patient infected with P. falciparum.