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Title: Elevated temperature triggers human respiratory syncytial virus F protein six-helix bundle formation

Abstract

Human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infection in infants, immunocompromised patients, and the elderly. The RSV fusion (F) protein mediates fusion of the viral envelope with the target cell membrane during virus entry and is a primary target for antiviral drug and vaccine development. The F protein contains two heptad repeat regions, HR1 and HR2. Peptides corresponding to these regions form a six-helix bundle structure that is thought to play a critical role in membrane fusion. However, characterization of six-helix bundle formation in native RSV F protein has been hindered by the fact that a trigger for F protein conformational change has yet to be identified. Here we demonstrate that RSV F protein on the surface of infected cells undergoes a conformational change following exposure to elevated temperature, resulting in the formation of the six-helix bundle structure. We first generated and characterized six-helix bundle-specific antibodies raised against recombinant peptides modeling the RSV F protein six-helix bundle structure. We then used these antibodies as probes to monitor RSV F protein six-helix bundle formation in response to a diverse array of potential triggers of conformational changes. We found that exposure of 'membrane-anchored' RSV Fmore » protein to elevated temperature (45-55 deg. C) was sufficient to trigger six-helix bundle formation. Antibody binding to the six-helix bundle conformation was detected by both flow cytometry and cell-surface immunoprecipitation of the RSV F protein. None of the other treatments, including interaction with a number of potential receptors, resulted in significant binding by six-helix bundle-specific antibodies. We conclude that native, untriggered RSV F protein exists in a metastable state that can be converted in vitro to the more stable, fusogenic six-helix bundle conformation by an increase in thermal energy. These findings help to better define the mechanism of RSV F-mediated membrane fusion and have important implications for the identification of therapeutic strategies and vaccines targeting RSV F protein conformational changes.« less

Authors:
; ; ; ; ; ; ;  [1];  [1]
  1. Panacos Pharmaceuticals, Inc., 209 Perry Parkway, Suite 7, Gaithersburg, MD 20877 (United States)
Publication Date:
OSTI Identifier:
21357583
Resource Type:
Journal Article
Resource Relation:
Journal Name: Virology; Journal Volume: 396; Journal Issue: 2; Other Information: DOI: 10.1016/j.virol.2009.10.040; PII: S0042-6822(09)00676-X; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ANTIBODIES; ANTI-INFECTIVE AGENTS; CELL MEMBRANES; CONFORMATIONAL CHANGES; PEPTIDES; RESPIRATORY SYSTEM DISEASES; VACCINES; VIRUSES; CELL CONSTITUENTS; DISEASES; DRUGS; MEMBRANES; MICROORGANISMS; ORGANIC COMPOUNDS; PARASITES; PROTEINS

Citation Formats

Yunus, Abdul S., Jackson, Trent P., Crisafi, Katherine, Burimski, Irina, Kilgore, Nicole R., Zoumplis, Dorian, Allaway, Graham P., Wild, Carl T., and Salzwedel, Karl, E-mail: salzwedelkd@niaid.nih.go. Elevated temperature triggers human respiratory syncytial virus F protein six-helix bundle formation. United States: N. p., 2010. Web. doi:10.1016/j.virol.2009.10.040.
Yunus, Abdul S., Jackson, Trent P., Crisafi, Katherine, Burimski, Irina, Kilgore, Nicole R., Zoumplis, Dorian, Allaway, Graham P., Wild, Carl T., & Salzwedel, Karl, E-mail: salzwedelkd@niaid.nih.go. Elevated temperature triggers human respiratory syncytial virus F protein six-helix bundle formation. United States. doi:10.1016/j.virol.2009.10.040.
Yunus, Abdul S., Jackson, Trent P., Crisafi, Katherine, Burimski, Irina, Kilgore, Nicole R., Zoumplis, Dorian, Allaway, Graham P., Wild, Carl T., and Salzwedel, Karl, E-mail: salzwedelkd@niaid.nih.go. Wed . "Elevated temperature triggers human respiratory syncytial virus F protein six-helix bundle formation". United States. doi:10.1016/j.virol.2009.10.040.
@article{osti_21357583,
title = {Elevated temperature triggers human respiratory syncytial virus F protein six-helix bundle formation},
author = {Yunus, Abdul S. and Jackson, Trent P. and Crisafi, Katherine and Burimski, Irina and Kilgore, Nicole R. and Zoumplis, Dorian and Allaway, Graham P. and Wild, Carl T. and Salzwedel, Karl, E-mail: salzwedelkd@niaid.nih.go},
abstractNote = {Human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infection in infants, immunocompromised patients, and the elderly. The RSV fusion (F) protein mediates fusion of the viral envelope with the target cell membrane during virus entry and is a primary target for antiviral drug and vaccine development. The F protein contains two heptad repeat regions, HR1 and HR2. Peptides corresponding to these regions form a six-helix bundle structure that is thought to play a critical role in membrane fusion. However, characterization of six-helix bundle formation in native RSV F protein has been hindered by the fact that a trigger for F protein conformational change has yet to be identified. Here we demonstrate that RSV F protein on the surface of infected cells undergoes a conformational change following exposure to elevated temperature, resulting in the formation of the six-helix bundle structure. We first generated and characterized six-helix bundle-specific antibodies raised against recombinant peptides modeling the RSV F protein six-helix bundle structure. We then used these antibodies as probes to monitor RSV F protein six-helix bundle formation in response to a diverse array of potential triggers of conformational changes. We found that exposure of 'membrane-anchored' RSV F protein to elevated temperature (45-55 deg. C) was sufficient to trigger six-helix bundle formation. Antibody binding to the six-helix bundle conformation was detected by both flow cytometry and cell-surface immunoprecipitation of the RSV F protein. None of the other treatments, including interaction with a number of potential receptors, resulted in significant binding by six-helix bundle-specific antibodies. We conclude that native, untriggered RSV F protein exists in a metastable state that can be converted in vitro to the more stable, fusogenic six-helix bundle conformation by an increase in thermal energy. These findings help to better define the mechanism of RSV F-mediated membrane fusion and have important implications for the identification of therapeutic strategies and vaccines targeting RSV F protein conformational changes.},
doi = {10.1016/j.virol.2009.10.040},
journal = {Virology},
number = 2,
volume = 396,
place = {United States},
year = {Wed Jan 20 00:00:00 EST 2010},
month = {Wed Jan 20 00:00:00 EST 2010}
}