title: Detailed mechanistic insights into HIV-1 sensitivity to three generations of fusion inhibitors.
abstract: Peptides based on the second heptad repeat (HR2) of viral class I fusion proteins are effective inhibitors of virus entry. One such fusion inhibitor has been approved for treatment of human immunodeficiency virus-1 (T20, enfuvirtide). Resistance to T20 usually maps to the peptide binding site in HR1. To better understand fusion inhibitor potency and resistance, we combined virological, computational, and biophysical experiments with comprehensive mutational analyses and tested resistance to T20 and second and third generation inhibitors (T1249 and T2635). We found that most amino acid substitutions caused resistance to the first generation peptide T20. Only charged amino acids caused resistance to T1249, and none caused resistance to T2635. Depending on the drug, we can distinguish four mechanisms of drug resistance: reduced contact, steric obstruction, electrostatic repulsion, and electrostatic attraction. Implications for the design of novel antiviral peptide inhibitors are discussed.
authors.affiliation: Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam, Academic Medical Center of the University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Dirk
authors.initials: D
authors.lastname: Eggink
authors.forename: Johannes P M
authors.initials: JP
authors.lastname: Langedijk
authors.forename: Alexandre M J J
authors.initials: AM
authors.lastname: Bonvin
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Deng
authors.forename: Min
authors.initials: M
authors.lastname: Lu
authors.forename: Ben
authors.initials: B
authors.lastname: Berkhout
authors.forename: Rogier W
authors.initials: RW
authors.lastname: Sanders
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D002942:Circular Dichroism; D000077560:Enfuvirtide; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D023581:HIV Fusion Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D020128:Inhibitory Concentration 50; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D010455:Peptides / Q000235:genetics / Q000494:pharmacology*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D055672:Static Electricity
chemical_list: D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D010446:Peptide Fragments; D010455:Peptides; C544608:T2635 peptide; C474741:peptide T1249; D000077560:Enfuvirtide