EN
The aim of this study was to clone new secretory antigen of Fasciola hepatica and to predict its availability for immune system. The new cathepsin L - FhPcW1 (F. hepatico cysteine proteinase Warsaw 1), GenBank accession: EF407948, cDNA was cloned from adult F. hepatica flukes using RACE-PCR method. FhPcW1 is encoded by a 1,066 bp mRNA with a predicted open reading frame (ORF) of 326 amino acids (predicted pl = 5.41, m.w. = 37.137 kDa). Performed bioinformatic analysis included alignments of the nucleotide and amino acid sequences, the ExPASy (Expert Protein Analysis System) proteomics server of the Swiss Institute of Bioinformatics and National Center for Biotechnology Information. Performed analyses allowed to suppose that FhPcW1 is a secreted protein, which contains signal peptide, serine, threonine, tyrosine phosphorylation sites and four tyrosine sulfation sites, and does not contain glycosylation sites. The ORF corresponding to FhPcW1 exhibited strong similarity to previously cloned cathepsins L from the F. hepatico as well as F. gigantica. Predicted biochemical characteristics fits to the described before F. hepatica cathepsin Ls. Moreover, three dimensional model and MHC types ligation strength prediction were performed. Analysis of MHC type I and II peptide binding suggests that FhPcW1 may have significant immunogenic potential. The potential HLA II epitopes are situated at the outer surface of this protein. Thus, these epitopes seems to be available for immune response, especially for antibodies. This result may show that FhPcW1 seems to be a promising antigen for vaccination against F. hepatica.