title: Chimeric Cyanovirin-MPER recombinantly engineered proteins cause cell-free virolysis of HIV-1.
abstract: Human immunodeficiency virus (HIV) is the primary etiologic agent responsible for the AIDS pandemic. In this work, we used a chimeric recombinant protein strategy to test the possibility of irreversibly destroying the HIV-1 virion using an agent that simultaneously binds the Env protein and viral membrane. We constructed a fusion of the lectin cyanovirin-N (CVN) and the gp41 membrane-proximal external region (MPER) peptide with a variable-length (Gly4Ser)x linker (where x is 4 or 8) between the C terminus of the former and N terminus of the latter. The His-tagged recombinant proteins, expressed in BL21(DE3)pLysS cells and purified by immobilized metal affinity chromatography followed by gel filtration, were found to display a nanomolar efficacy in blocking BaL-pseudotyped HIV-1 infection of HOS.T4.R5 cells. This antiviral activity was HIV-1 specific, since it did not inhibit cell infection by vesicular stomatitis virus (VSV) or amphotropic-murine leukemia virus. Importantly, the chimeric proteins were found to release intraviral p24 protein from both BaL-pseudotyped HIV-1 and fully infectious BaL HIV-1 in a dose-dependent manner in the absence of host cells. The addition of either MPER or CVN was found to outcompete this virolytic effect, indicating that both components of the chimera are required for virolysis. The finding that engaging the Env protein spike and membrane using a chimeric ligand can destabilize the virus and lead to inactivation opens up a means to investigate virus particle metastability and to evaluate this approach for inactivation at the earliest stages of exposure to virus and before host cell encounter.
authors.affiliation: Drexel University College of Medicine, Department of Biochemistry and Molecular Biology, Philadelphia, Pennsylvania, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Contarino
authors.forename: Arangassery R
authors.initials: AR
authors.lastname: Bastian
authors.forename: Ramalingam Venkat
authors.initials: RV
authors.lastname: Kalyana Sundaram
authors.forename: Karyn
authors.initials: K
authors.lastname: McFadden
authors.forename: Caitlin
authors.initials: C
authors.lastname: Duffy
authors.forename: Vamshi
authors.initials: V
authors.lastname: Gangupomu
authors.forename: Michelle
authors.initials: M
authors.lastname: Baker
authors.forename: Cameron
authors.initials: C
authors.lastname: Abrams
authors.forename: Irwin
authors.initials: I
authors.lastname: Chaiken
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D015700:HIV Envelope Protein gp41 / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D010957:Plasmids; D015202:Protein Engineering; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D015700:HIV Envelope Protein gp41; D011993:Recombinant Fusion Proteins; C107733:cyanovirin N