title: A novel chimeric protein-based HIV-1 fusion inhibitor targeting gp41 glycoprotein with high potency and stability.
abstract: T20 (enfuvirtide, Fuzeon) is the first generation HIV-1 fusion inhibitor approved for salvage therapy of HIV-1-infected patients refractory to current antiretroviral drugs. However, its application is limited by the high cost of peptide synthesis, rapid proteolysis, and poor efficacy against emerging drug-resistant strains. Here we reported the design of a novel chimera protein-based fusion inhibitor targeting gp41, TLT35, that uses a flexible 35-mer linker to couple T20 and T1144, the first and next generation HIV-1 fusion inhibitors, respectively. TLT35, which was expressed in Escherichia coli with good yield, showed low nm activity against HIV-1-mediated cell-cell fusion and infection by laboratory-adapted HIV-1 strains (X4 or R5), including T20-resistant variants and primary HIV-1 isolates of clades A to G and group O (R5 or X4R5). TLT35 was stable in human sera and in peripheral blood mononuclear cell culture and was more resistant to proteolysis than either T20 or T1144 alone. Circular dichroism spectra showed that TLT35 folded into a thermally stable conformation with high α-helical content and T(m) value in aqueous solution. It formed a highly stable complex with gp41 N-terminal heptad repeat peptide and blocked formation of the gp41 six-helix-bundle core. These merits combined with an anticipated low production cost for expression of TLT35 in E. coli make this novel protein-based fusion inhibitor a promising candidate for further development as an anti-HIV-1 microbicide or therapeutic for the prevention and treatment of HIV-1 infection.
authors.affiliation: Lindsley F Kimball Research Institute, New York Blood Center, New York, New York 10065, USA.
authors.forename: Chungen
authors.initials: C
authors.lastname: Pan
authors.forename: Lifeng
authors.initials: L
authors.lastname: Cai
authors.forename: Hong
authors.initials: H
authors.lastname: Lu
authors.forename: Lu
authors.initials: L
authors.lastname: Lu
authors.forename: Shibo
authors.initials: S
authors.lastname: Jiang
mesh_terms: D002460:Cell Line; D002942:Circular Dichroism; D024882:Drug Resistance, Viral / Q000187:drug effects*; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D015700:HIV Envelope Protein gp41 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D023581:HIV Fusion Inhibitors / Q000737:chemistry / Q000494:pharmacology; D015658:HIV Infections / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D053586:Virus Internalization / Q000187:drug effects*
chemical_list: D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D011993:Recombinant Fusion Proteins; C514787:gp41 protein, Human immunodeficiency virus 1