美洲大蠊Per a7基因的克隆、表达及免疫学鉴定

根据原肌球蛋白基因序列设计引物，以我国南方地区美洲大蠊Periplaneta Americana RNA为模板，用RT-PCR方法扩增出852 bp的全长编码片段，经序列分析发现该基因与NCBI公布的Per a7有3个核苷酸发生改变。将目的片段克隆到pET24a(+)表达载体中，在大肠杆菌BL21 Star获得表达，融合蛋白的分子量约为33 kD。利用蟑螂过敏性患者血清对表达产物进行Western blotting检测，出现明显的识别条带，说明表达产物具有IgE结合活性。

Cloning,expression and immunological identification of Per a7 gene of the American cockroach,Periplaneta americana

An 852 bp cDNA fragment was amplified by RT-PCR from total mRNA of the American cockroach,Periplaneta americana(South China population)with a pair of primers that were designed according to the published tropomyosin gene.Sequence analysis indicated that three nucleotides changed in the gene compared with the reported Per a7 gene.The fragment was cloned into expression vector pET24a( )and subsequently expressed in E.coli BL21 Star.SDS-PAGE analysis showed that the molecular weight of the expressed product was 33 kD.Western blotting indicated that the recombinant protein could combine with sera IgE from human individuals allergic to cockroach allergens.