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This content will become publicly available on April 7, 2016

Title: Dynamic changes during acid-induced activation of influenza hemagglutinin

Influenza hemagglutinin (HA) mediates virus attachment to host cells and fusion of the viral and endosomal membranes during entry. While high-resolution structures are available for the pre-fusion HA ectodomain and the post-fusion HA2 subunit, the sequence of conformational changes during HA activation has eluded structural characterization. In this paper, we apply hydrogen-deuterium exchange with mass spectrometry to examine changes in structural dynamics of the HA ectodomain at various stages of activation, and compare the soluble ectodomain with intact HA on virions. At pH conditions approaching activation (pH 6.0–5.5) HA exhibits increased dynamics at the fusion peptide and neighboring regions, while the interface between receptor binding subunits (HA1) becomes stabilized. In contrast to many activation models, these data suggest that HA responds to endosomal acidification by releasing the fusion peptide prior to HA1 uncaging and the spring-loaded refolding of HA2. Finally, this staged process may facilitate efficient HA-mediated fusion.
Authors:
 [1] ;  [1] ;  [1] ;  [1]
  1. Univ. of Washington, Seattle, WA (United States)
Publication Date:
OSTI Identifier:
1246554
Grant/Contract Number:
T32-GM007750; F32-GM097805; R00-GM080352; R01-GM099989; P41-GM103393; P41-RR001209
Type:
Published Article
Journal Name:
Structure
Additional Journal Information:
Journal Volume: 23; Journal Issue: 4; Journal ID: ISSN 0969-2126
Publisher:
Elsevier
Research Org:
Univ. of Washington, Seattle, WA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Inst. of Health (NIH) (United States)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY