title: A novel HIV-1 gp41 tripartite model for rational design of HIV-1 fusion inhibitors with improved antiviral activity.
abstract: During HIV-1 fusion process, the N-terminal heptad repeat (NHR) of the HIV-1 glycoprotein 41 (gp41) interacts with the C-terminal heptad repeat (CHR) to form the fusion active six-helix bundle, thus being an effective target for the design of CHR peptide-based HIV-1 fusion inhibitors. To overcome the limitations of the simplified helix wheel model of six-helix bundle, we herein developed a novel HIV-1 gp41 NHR-CHR-NHR tripartite model for the rational design of HIV-1 fusion inhibitors with improved antiviral activities.
  
  
  
  Based on the crystal structure of six-helix bundle, we evaluated the NHR-binding properties of each residue in CHR. In this new tripartite model, CHR residues were divided into three groups: major binding, nonbinding, and assistant binding sites.
  
  
  
  Eight CHR peptides were designed and synthesized to confirm the validity of the tripartite model. Their affinities to NHR and inhibitory activities were analyzed.
  
  
  
  In this tripartite model, replacements in assistant binding sites either increased or decreased the inhibition of HIV-1 infection. We identified three peptides with mutations of the residues in CHR at the assistant binding sites in our tripartite model but nonbinding sites in the helical wheel model. These mutant peptides had anti-HIV-1 activity up to 26-fold more potent than that of C34, a CHR peptide designed on the basis of the helix wheel model.
  
  
  
  These data verified the superiority and validity of our new tripartite model for the rational design of HIV-1 fusion inhibitors. This approach can be adapted for designing viral fusion inhibitors against other enveloped viruses with class I membrane fusion protein.
authors.affiliation: aKey Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences and Shanghai Public Health Clinical Center, Fudan University, Xuhui District, Shanghai bNational Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing cKey Laboratory of Reproduction Regulation of NPFPC, SIPPR, IRD, Fudan University, Shanghai, China dLindsley F. Kimball Research Institute, New York Blood Center, New York City, New York, USA.
authors.forename: Shan
authors.initials: S
authors.lastname: Su
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
authors.forename: Chen
authors.initials: C
authors.lastname: Hua
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhu
authors.forename: Shibo
authors.initials: S
authors.lastname: Jiang
authors.forename: Lu
authors.initials: L
authors.lastname: Lu
mesh_terms: D018360:Crystallography, X-Ray; D055808:Drug Discovery / Q000379:methods*; D015700:HIV Envelope Protein gp41 / Q000737:chemistry* / Q000378:metabolism; D023581:HIV Fusion Inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; C514787:gp41 protein, Human immunodeficiency virus 1