Small molecules VP-14637 and JNJ-2408068 inhibit respiratory syncytial virus fusion by similar mechanisms

Janet L. Douglas, Marites L. Panis, Edmund Ho, Kuei Ying Lin, Steve H. Krawczyk, Deborah M. Grant, Ruby Cai, Swami Swaminathan, Xiaowu Chen, Tomas Cihlar

Research output: Contribution to journalArticlepeer-review

90 Scopus citations


Here we present data on the mechanism of action of VP-14637 and JNJ-2408068 (formerly R-170591), two small-molecule inhibitors of respiratory syncytial virus (RSV). Both inhibitors exhibited potent antiviral activity with 50% effective concentrations (EC50S) of 1.4 and 2.1 nM, respectively. A similar inhibitory effect was observed in a RSV-mediated cell fusion assay (EC50 = 5.4 and 0.9 nM, respectively). Several drug-resistant RSV variants were selected in vitro in the presence of each compound. All selected viruses exhibited significant cross-resistance to both inhibitors and contained various single amino acid substitutions in two distinct regions of the viral F protein, the heptad repeat 2 (HR2; mutations D486N, E487D, and F488Y), and the intervening domain between HR1 and HR2 (mutation K399I and T400A). Studies using [3H]VP-14637 revealed a specific binding of the compound to RSV-infected cells that was efficiently inhibited by JNJ-2408068 (50% inhibitory concentration = 2.9 nM) but not by the HR2-derived peptide T-118. Further analysis using a transient T7 vaccinia expression system indicated that RSV F protein is sufficient for this interaction. F proteins containing either the VP-14637 or JNJ-2408068 resistance mutations exhibited greatly reduced binding of [3H]VP-14637. Molecular modeling analysis suggests that both molecules may bind into a small hydrophobic cavity in the inner core of F protein, interacting simultaneously with both the HR1 and HR2 domains. Altogether, these data indicate that VP-14637 and JNJ-2408068 interfere with RSV fusion through a mechanism involving a similar interaction with the F protein.

Original languageEnglish (US)
Pages (from-to)2460-2466
Number of pages7
JournalAntimicrobial agents and chemotherapy
Issue number6
StatePublished - Jun 2005
Externally publishedYes

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)
  • Infectious Diseases


Dive into the research topics of 'Small molecules VP-14637 and JNJ-2408068 inhibit respiratory syncytial virus fusion by similar mechanisms'. Together they form a unique fingerprint.

Cite this