Abstract: 　Objective] To subclone and characterize a cDNA clone coding for Schistosoma japonicum (S.j.) mitochondria-related protein. [Methods] The open reading frame of the fragment(Sj338/24) obtained from an adult worm cDNA library of S j. was analysed, at the upstream and downstream of the open reading frame(ORF) the primers A and B were designed,respectively, and the cDNA fragment was used as PCR template. The Sj338 gene fragment obtained was amplified by PCR method and then subcloned into pGEM-T vector for sequencing. The gene sequence was analyzed and the target fragment was restrictedly digested and subcloned into expression vector pGEX-6P-1. The expressed recombinant protein was purified and characterized. [Results] The cloned Sj338 gene was demonstrated to be 487 bp long containing one 459 bp ORF, encoding a protein with a molecular weight of 17 kDa.The nucleotide sequence of the cloned gene Sj338 had higher homology with those genes coding for mitochondrial outer membrane protein of Homo sapiens and Rattus norvegicus . The recombinant construct of pGEX-6P-1/Sj338 could be expressed efficiently and the antigenicity of its product rSj338 has been demonstrated by Western blotting. [Conclusion] Sj338 may be the gene coding for S j. mitochondria-related protein and the recombinant protein may be used as a new vaccine candidate .

Key words: Schistosoma japonicum, mitochondria, gene cloning, recombinant antigen, fusion expression