ABSTRACT
The constrained alpha-helical structure of a C-peptide is useful for enhancing anti-HIV-1 activity. The i and i+3 positions in an alpha-helical structure are located close together, therefore D-Cys (dC) and L-Cys (C) were introduced at the positions, respectively, to make a dC-C disulfide bond in 28mer C-peptides. Accordingly, this study tested whether a dC-C disulfide bond would increase the alpha-helicity and anti-HIV-1 activity of peptides. A C-peptide can be divided into three domains, the N-terminal hydrophobic domain (HPD), middle interface domain (IFD), and C-terminal hydrogen domain (HGD), based on the binding property with an N-peptide. In general, the dC-C modifications in HPD enhanced the anti-HIV-1 activity, while those in IFD and HGD resulted in no or much less activity. The modified peptides with no activity clearly showed much less alpha-helicity than the native peptides, while those with higher activity showed an almost similar or slightly increased alpha-helicity. Therefore, the present results suggest that the introduction of a dC-C bridge in the N-terminal hydrophobic domain of a C-peptide may be useful for enhancing the anti-HIV-1 activity.
Subject(s)
Humans , Amino Acid Sequence , Anti-HIV Agents/chemical synthesis , Cell Line , Circular Dichroism , Cysteine/chemistry , Disulfides/chemistry , HIV Envelope Protein gp41/chemistry , HIV-1/drug effects , Inhibitory Concentration 50 , Models, Molecular , Molecular Sequence Data , Peptides/chemical synthesis , Protein Structure, Secondary , Protein Structure, Tertiary , Structure-Activity RelationshipABSTRACT
Objective To construct recombinant plasmid with p24 and gp41 gene, express fusion protein in E.coli. Methods To design primer with restriction endonuclease position,and amplify p24 and gp41 by RT-PCR, link both into pMD18-T vector.To choose correct clone with target gene.Then p24 fragment will be cleaved and linked into pMD18-T vector within gp41 gene. Both post-linked gene will be cleaved and linked into pET21a vector. The vector will be transformed into E.coli. And protein is highly effective expressed in E coli. Western blotting proved that the expressed product could react with 6?his antibody. Result Fusion protein p24-gp41 is highly effective expressed in E.coli. Conclusion Fusion protein p24-gp41 is highly effective expressed in E.coli in pET21a vector.