1.Gene Clone, Expression And Epitope Mapping Of Hepatitis C Virus E1 Protein 2.Nucleotide Sequence Analyses Of Provirus Gene Of Human T-Lymphotropic Virus Type Ⅰ From An Inhabitant Of Shaotou Region In Southeast China

Hepatitis C virus( HCV ) is a major causative agent of posttransfusion-transmitted and community-acquired non-A, non-B hepatitis. There is no effective vaccine and drug to control HCV infection up to now. El protein, as an envelope protein of HCV, is a major target of host immune system. It can induce humoral/cellular immune response. In this study, we described the cloning of HCV El gene isolated from a Chinese, the expression and purification of the El protein, and epitope mapping of the protein by using random peptide libraries.1. Cloning and expression of HCV El gene in prokaryotic expression system: HCV RNA was extracted from a serum sample collecting from Hebei Province, China. The full length Elgene was amplified by RT-PCR. HCV El cDNA was inserted into pQE30 plasmid and expressed in E.coli Ml5. Eleven clones expressed truncated El protein in eighty-six recombinant clones. No full-length El protein (21kD or so) was synthesized. One clone (HCVel 18), which expressed the longest Elprotein (about 16kD) among all expressive recombinant clones was sequenced. The result showed that (1) The DNA sequence of the cloned gene has identity of 56.3%-96.9% with genotype of HCV I-VI, the identity of amino acid sequence among them was 47.7%-97.5%. The phylogenetic tree showed that the HCV isolate belongs to HCV II/1b. (2) The stop-code in HCVel 18 was formed because of the mutation in 1347 position (C→T). After correcting the mutation by using site-directed mutagenesis methods, the HCV El gene with correct ORF was obtained. The modified HCV El gene was inserted into pQE30 plasmid and expressed in E.coli M15, but no protein was synthesized. Another...