title: Design and characterization of swapped-domain constructs of HIV-1 glycoprotein-41 as receptors for drug discovery.
abstract: Four new swapped-domain constructs of the ectodomain of human immunodeficiency virus type 1 glycoprotein-41 (gp41) were prepared. The gp41 ectodomain consists of 50-residue N-heptad repeat (NHR), 36-residue disulfide-bonded loop and 39-residue C-heptad repeat (CHR). It folds into a hairpin structure that forms a trimer along the NHR axis. The swapped-domain proteins feature CHR domains of length 39, 28 or 21 residues preceding a 4-residue loop and a 49- or 50-residue NHR domain. The effect of CHR truncation was to expose increasing lengths of the NHR groove, including the conserved hydrophobic pocket, an important drug target. A novel method for preparing proteins with extended exposed hydrophobic surfaces was demonstrated. Biophysical measurements, including analytical ultracentrifugation and ligand-detected Water-Ligand Observed via Gradient Spectroscopy and (1)H-(15)N-HSQC NMR experiments, were used to confirm that the proteins formed stable trimers in solution with exposed binding surfaces. These proteins could play an important role as receptors in structure-based drug discovery.
authors: Department of Basic Sciences, College of Osteopathic Medicine, Touro University California, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA.
authors: Joseph D
authors: JD
authors: Walsh
authors: Department of Basic Sciences, College of Osteopathic Medicine, Touro University California, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA.
authors: Shidong
authors: S
authors: Chu
authors: Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19014, USA.
authors: Shao-Qing
authors: SQ
authors: Zhang
authors: Department of Basic Sciences, College of Osteopathic Medicine, Touro University California, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA miriam.gochin@tu.edu.
authors: Miriam
authors: M
authors: Gochin
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D055592:Biophysical Phenomena; D002942:Circular Dichroism; D055808:Drug Discovery; D015700:HIV Envelope Protein gp41 / Q000737:chemistry* / Q000235:genetics; D023581:HIV Fusion Inhibitors / Q000737:chemistry; D015497:HIV-1 / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions / Q000187:drug effects; D008024:Ligands; D008561:Membrane Fusion / Q000187:drug effects; D011485:Protein Binding; D011487:Protein Conformation / Q000187:drug effects*; D017434:Protein Structure, Tertiary; D054852:Small Molecule Libraries / Q000494:pharmacology
chemical_list: D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D008024:Ligands; D054852:Small Molecule Libraries
keywords: GB1-gp41 peptide fusion protein; NHR groove; ligand-based NMR screening; overexpression of hydrophobic protein; reverse hairpin gp41 trimer