Abstract:Aim To predict the secondary structure of the cDNA encoding Schistosoma japonicum(Sj) arginase.Methods By using bioinformatics,the cDNA sequence encoding Sj arginase was analyzed,including searching the ORF,translating the nucleotide to protein sequence,similarity searches and secondary structure predication.Results The cDNA fragment with 1061 bp included a FRO with 840nt,and translated into 279 amino acid residues.The deduced protein was similar to the arginase family,the homology at amino acid sequence level was 44%,50%,51%,53% and 54% with Schizosaccharomyces pombe(fission yeast) arginase,Xenopus laevis(African clawed frog) arginase,Homo sapiens(human) arginase ii precursor and Rattus norvegicus(rat) arginase ii precursor respectively.The amino acid in beta-trun,hydrophobicity,flexibity and coil were possibly localized in tis N-terminal No.30~50,70~90 and 180~200,these site were probaly potential antigen epitopes.Conclusion This poly peptide of Sj arginase is considered to have stronger antigenicity.