刚地弓形虫SAG3基因体外扩增及生物信息学分析

Amplification and Bioinformatics Analysis of SAG3 Gene of Toxoplasma gondii Strain RH in Vitro

目的获取刚地弓形虫(Toxoplasma gondii)RH株表面抗原SAG3目的基因片段,对其结构和功能进行生物信息学分析,预测其编码蛋白作为候选抗原基因的可行性。方法提取弓形虫的基因组DNA,自行设计一对寡核苷酸引物,PCR体外扩增SAG3基因,用生物信息学方法对SAG3蛋白的理化性质、结构和功能进行预测。结果扩增出的基因片段约1174bp,测序后鉴定其为弓形虫RH株SAG3基因片段。预测SAG3蛋白相对分子质量约为41785.2,能形成两个功能结构域,氨基酸序列的前38(或39)位为信号肽序列。通过多种预测方法分析SAG3氨基酸序列抗原表位可能位于第10、50、80、95、160、180、220、250、300、330和360位点内或附近。结论成功获得SAG3基因,为深入研究该基因结构奠定了基础。

Objective To amplify strain RH of Toxoplasma gondii surface antigen SAG3, analyze the features by bioinformatics and predict the vaccination potential of the protein encoded by SAG3 gene. Method Genomic DNA of strain RH of T.gondii was extracted, and a pair of specific primers were designed and used to amplify the SAG3 by PCR. Using bioinformatics analysis software, the physicochemical characteristic, structure and function of SAG3 protein was predicted. Results The target gene was amplified with the length of 1 174 bp. Analysis showed that it was the SAG3 gene of T.gondii of RH strain. The predicted SAG3 protein molecular mass is 41 785.2, which can form two functional domains, with a signal peptide located before 38-39 amino acids. The antigen peptides are predicted to locate at or around the position 10, 50, 80, 95, 160, 180, 220, 250, 300, 330 and 360 of the protein. Conclusion SAG3 gene of T.gondii of RH strain was amplified by PCR. SAG3 may be a potential vaccine candidate of T.gondii.