부산대학교 도서관

The antigenicity of two recombinant NS3 proteins cloned in E. coli was compared by ELISA. The truncated rNS3 recombinant protein encompasses the amino acids from 1234 to 1432 of the Hepatitis C Virus (HCV) polyprotein, and the CIB-c33c protein encloses the entire HCV c33c sequence (aa 1192-1457). Seroconversion sera to NS3 from the Boston Biomedical panel PHV908 were used for evaluation. Our results show that the CIB-c33c protein has a better antigenicity than the rNS3 protein. Antigen CIB-c33c was recognized by the sera at the HCV seroconversion phase exclusively with antibodies against the NS3 region. Comparisons between both proteins suggest that the 25 aa fragment sequence presented at the c33c carboxyl-terminal is important for antibody recognition. The synthetic peptide encompassing this 25 amino acid fragment was not recognized by sera in seroconversion for HCV, suggesting that this fragment requires the presence of the remaining c33c region to expose its antigenicity. The new variant of the c33c protein obtained (CIB-c33c), expressed at high levels in E. coli and highly purified (>90% of purity) by onestep metal affinity chromatography, showed improved antigenic properties. Moreover, it increased the performance of anti-HCV diagnosis, and was able to detect sera in the seroconversion phase, thereby reducing the diagnostic seronegative window. [ABSTRACT FROM AUTHOR]