Cloning and expression of the gene encoding hypoxanthine-guanine phosphoribosyltransferase of Schistosoma japonicum / 中国血吸虫病防治杂志

ABSTRACT

Objective To perform the cloning of the gene encoding Schistosoma japonicum Chinese-strain hypoxanthine-guanine phosphoribosyltransferase(HGPRT)and its expression in Escherichia coli.MethodsA couple of primers were designed with the BamHI restriction endonuclease site introduced in forward primer and SalI in reverse primer.Total RNA was isolated from adult worms of S.japonicum Chinese-strain(Anhui-strain,Sjc-A)and the SjcHGPRT gene was amplified by reverse transcriptase-polymerase chain reaction(RT-PCR).The PCR product and the prokaryotic expression vector pET28a were digested by both restriction endonucleases BamHI and SalI.The target DNA fragments were purified and cloned properly into pET28a.After identification by en-donucleases digestion,PCR and sequencing,the recombinant plasmid pET28a-SjcHG PRT was transformed into competent E.coli BL21 and expressed in the presence of IPTG.Results pET28a-SjHGPRT was sequenced and shown to be 99% and 83% identical in deduced amino acid sequence to that of S.japonicum Chinese-strain(Hunan-strain,Sjc-H)and S.mansoni HGPRT,respectively.The results of SDS-PAGE and Western blot revealed that the molecular weight of expressed protein was around 30 kDa and could be recognized by anti-His-G-HPR antibody and sera from mice and human with schistosomasis japonica.Conclusion The recombinant plasmid containing SjcHGPRT cDNA is successfully constructed and its expression protein(reSjcHGPRT)is also successfully purified.