Study Of Novel HIV-1 Peptide Inhibitors And Their Mechanism

The glycoprotein gp41 locates on the surface membrane of HIV-1, which plays an important role for virus infection by inducing the membrane fusion process. gp41 could be divided into several domains, which provide useful targets for the development of novel anti-virus drugs and vaccines. Some important domains on gp41 were chosen to be studied in various ways, to investigate novel anti-fusion drugs and the exact mechanism of virus membrane fusion. The creative achievements are described below.We conducted a yeast two-hybrid screening on a human bone marrow cDNA library using gp41 ectodomain as the bait and identified a novel gp41 core-binding molecule, designated P20. It could bind to the six-helix bundle core structure, and potently inhibit the membrane fusion process. We prepared eleven P20 mutants and investigated their characters. P20 was effective in inhibiting infection by a broad spectrum of HIV-1 strain, including the T-20 resistant strains. The interaction site between P20 and gp41 may be a novel drug target. The inhibit effect of P20 were closely related with its binding ability with 6-HB, and its C-terminal sequence WGRLEGRRT was its core functional site. So it could be used for developing novel HIV fusion inhibitors. Also, we expressed and purified N63 protein based on the NHR sequences. A 12AA peptide sequence was screened out to interact with N63 using the phage display peptide libraries. We found an inhibition receptor on NK cells had the same protein sequence. Only if their interactions are further confirmed, we will possibly uncover the novel functions of gp41.We also expressed and purified the LLP1-2 domain on gp41 for the first time in the world, together with three mutations in their arginine sites. Then we found that the highly conserved arginines on LLP-1 maintain the polymer structure form. HIV-1 with same mutations was replication defective and decreased in infectivity. With the LLP1-2 specific mAb, LLP-2 domain was proved to be transiently exposed on the membrane surface during the fusion process. It provided detailed evidence for the virus fusion model and important target for drug design.