Screening for specific membrane protein of Schistosoma japonicum and cloning of sequence encoding protein sj15 / 第二军医大学学报

ABSTRACT

Objective: To screen for the potential specific membrane protein from the protein database built by our Lab and to clone the encoding sequence of a potential immunoprotective protein according to the screening result, so as to search for new vaccine candidate or drug targets for Schistosomiasis control. Methods: The related data were retrieved using the key words "Schistosoma japonicum" and "membrane or tegument" from the NCBI database to construct local database of membrane protein of S. japonicum. The specific membrane proteins were screened by multi-alignment with the protein sequences from our local database of Schistosoma mansoni, Homo sapiens, Rattus norvegicus and Mus musculus. Meanwhile, the character and function of the predicted membrane protein were analyzed with public software in the website CBS. The specific primer for the sequence of the predicted protein with potential immuno-protective function were designed and synthetized; the coding sequence was then amplified from the adult worm of S. japonicum by PCIZ and was cloned into rokaryotic expression vector pGEX-4T-1. Results: A total of 153 predicted membrane protein of S. japonicum were retrieved and 28 potentially specific for S. japonicum were screened out. The coding sequence of the predicted protein, with a relative molecular weight of about 15 000, was successfully amplified from the adult worm of S. japonicum and was temporarily named gene sj15; the recombinant plasmid pGEX-4T-1-sjl5 was also successfully constructed. Conclusion: Many specific membrane proteins of S. japonicum have been successfully screened out. The predicted sjl5 gene (announced as AY223457 in GenBank) has been successfully cloned, proving the existence of sj15 gene in adult worm of S. japonicum. The prokaryotic expression vector pGEX-4T-1 for sj15 has also been successfully constructed, providing a foundation for further study of sj15 function.