الفهرس 
Introduction and review of literatureOnly 14 pages are availabe for public view
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Abstract
Hepatitis C virus (HCV) NS3 protease is a potential target for anti-HCV therapy as well as a good vaccine candidate. In this study, the HCV protease gene was amplified from Egyptian sera by nested PCR and cloned downstream of the CMV promoter in a mammalian expression plasmid, which was then used to transform bacteria. Colonies carrying the gene in the correct orientation were subjected to large-scale plasmid purification followed by sequencing. Phylogenetic comparison of the sequence obtained with published sequences from different genotypes confirmed that our sequence belongs to genotype 4a. Of the other genotypes, the most closely related ones were from genotype 1. Multiple alignments of protease peptides showed that the catalytic triads and binding residues for substrate, Zn2+ and the NS4 cofactor are conserved among different isolates, including ours, and confirmed the closer homology between NS3 of genotypes 4 and 1. The HCV-protease-encoding construct was successfully transcribed in both mammalian cells and mice. Mouse antibodies produced against the protease-encoding-construct detected the 18-kDa enzyme in lysates of cells transfected with the construct by Western blotting. The present results encourage future characterization of the induced cellular and humoral immune responses by the NS3 protease construct to evaluate its potential as a therapeutic vaccine.