Sequence analysis of the structural protein region revealed extremely low sequence homology with all the four major HCV genotypes: 86-89% for the core protein and 56-69% for the envelope protein.
To identify conserved humoral antigenic determinants within the hepatitis C virus (HCV) envelope protein E2, we expressed a peptide library containing random short fragments of the HCV envelope in yeast.
To evaluate the implications of sequence variability in HVRI of HCV, we investigated the sequence variability of the whole envelope-protein(gp35 and gp70)-coding regions of HCV genome derived from patient M in acute and relapsed phases (8-month interval) of hepatitis.
These studies provide evidence that the highly conserved core protein is a target for HCV-specific CTL and identify CTL epitopes within the more highly variable E2 envelope protein.
The prevalence of antibody to the protein encoded by the NS1 region was lower than that of antibody to the HCV core protein, but much higher than that of antibody to the envelope protein.
This finding suggests that nucleotide mutations in the envelope region of the viral genome may be responsible for the recurrent hepatic injury attributed to recurrence of viremia in patients with hepatitis C. From these aspects, the serial divergence of the virus genome in infected individuals, especially in the region encoding the viral envelope protein, may possibly play an important role in developing chronic infection of hepatitis C virus.
Low sequence similarity in the putative envelope protein (greater than 53% identity), however, would have to be taken into account in considering the immunoprophylaxis of HCV infection.
The putative nucleocapsid and envelope protein genes of hepatitis C virus determined by comparison of the nucleotide sequences of two isolates derived from an experimentally infected chimpanzee and healthy human carriers.