作　　者： ; ; ; ; ; ;

机构地区： 长春农牧大学

出　　处： 《宁夏农学院学报》 1995年第4期28-34,共7页

摘　　要： 对已构建的重组质粒ｐＸＳＴ１（含有ＳＴ１和ＬａｃＺ基因）进行了核苷酸序列分析和免疫原性研究。序列分析结果表明，该质粒中含有２个正向串联在一起的ＳＴ１基因，且融合在ＬａｃＺ基因的上游，具有正确的阅读框架。免疫实验结果表明，构建的ＤＨ５α（ＰＸＳＴ１）重组菌株安全无毒。该重组菌株表达的ＳＴ１融合蛋白能够诱发ＢＡＬＢ／ｃ鼠产生抗体，且抗体能中和天然ＳＴ１肠毒素活性，具有较好的免疫保护作用。这表明ＤＨ５α（ｐＸＳＴ１）工程菌株可以作为预防幼畜腹泻的菌苗候选株。 The 5'terminus of the gene that codes for the heat-stable enterotoxin I of Escherichia colt (T1) was genetically fused to the 3'terminus of the LacZ gene that codes for the β-galactosidase. We constructed the recombinant plasmid pXST1 and studied it in detail by DNA sequencing. The results showed that the pXST1 carried two T1 genes,had positive reading frame, and coule express the T1-β-glactosidase fusion protein. More importantly, the fusion protein was nontoxic and immungenic. BALB/c mice imunized with crude prepation containing the fusion protein produced antibodies that was recognize T1 enterotoxin in vitro,ignificantly. These sera antibodies were able to neutralize the biological activity of native T1 enterotoxin in the suckling mouse assay. Hence the recombinant strain DH5α(pXST1 )can be used candidate of vaccine strain.

关 键 词： 大肠杆菌 耐热性 肠毒素 融合蛋白 免疫原性

领　　域： [农业科学] [农业科学] [农业科学]