日本血吸虫SjEA基因的克隆和分析

Cloning and Characterization of Schistosoma japonicum Gene SjEA

为获得新的可表达保护性抗原分子的编码基因,以日本血吸虫虫卵抗原免疫血清筛选日本血吸虫虫卵cDNA 文库,对获得的阳性克隆进行 PCR 鉴定并测序后,通过互联网将测序结果进行同源性分析和功能预测.结果发现,筛选到 3 个与 GenBank 中 SjEA 基因(登录号为 AB017096)具有 100%同源性的阳性克隆.序列分析表明,该基因全长 774 bp,编码 257 个氨基酸,编码蛋白的等电点为 8.76,相对分子质量为 28 900;为一非跨膜蛋白,二级结构预测具有 2 个 α-螺旋区,3 个β-折叠区,4 个无规卷曲区,具有一个称为 TonB 的 PS00430 保守区.

To obtain novel genes encoding new and potential protective antigens.Schistosoma japonicum egg cDNA library was immunoscreened with sera from mouse immunized with Schistosoma japonicum egg antigen.The inserts of positive clones were amplified by PCR and sequenced.The obstained data were analyzed with Nucleotide BLAST software of NCBI and Export Protein Analysis of Swiss Institute of Bioinformatics.The results indicated based on sequence analysis,the obstained 3 positive plaques were SjEA of 774 bp encoding a protein of 257amino acides,pI 8.76 and MW28 900 being a non-transmembrane protein.It had 100% homo geneous with gene (GenBank accession number: AB017096).Secondary structural predication showed this protein possess 2 α-helix,3β-sheet and 4 random coil; Conserved domain anlysis results showed it has a PS00430 ( called TonB).