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Nature - Receptor binding by a ferret-transmissible H5 avian influenza virus

tetano

Editor, Senior Moderator
Nature. 2013 Apr 24. doi: 10.1038/nature12144. [Epub ahead of print]
Receptor binding by a ferret-transmissible H5 avian influenza virus.
Xiong X, Coombs PJ, Martin SR, Liu J, Xiao H, McCauley JW, Locher K, Walker PA, Collins PJ, Kawaoka Y, Skehel JJ, Gamblin SJ.
Source

1] MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK [2].
Abstract

Cell-surface-receptor binding by influenza viruses is a key determinant of their transmissibility, both from avian and animal species to humans as well as from human to human. Highly pathogenic avian H5N1 viruses that are a threat to public health have been observed to acquire affinity for human receptors, and transmissible-mutant-selection experiments have identified a virus that is transmissible in ferrets, the generally accepted experimental model for influenza in humans. Here, our quantitative biophysical measurements of the receptor-binding properties of haemagglutinin (HA) from the transmissible mutant indicate a small increase in affinity for human receptor and a marked decrease in affinity for avian receptor. From analysis of virus and HA binding data we have derived an algorithm that predicts virus avidity from the affinity of individual HA-receptor interactions. It reveals that the transmissible-mutant virus has a 200-fold preference for binding human over avian receptors. The crystal structure of the transmissible-mutant HA in complex with receptor analogues shows that it has acquired the ability to bind human receptor in the same folded-back conformation as seen for HA from the 1918, 1957 (ref. 4), 1968 (ref. 5) and 2009 (ref. 6) pandemic viruses. This binding mode is substantially different from that by which non-transmissible wild-type H5 virus HA binds human receptor. The structure of the complex also explains how the change in preference from avian to human receptors arises from the Gln226Leu substitution, which facilitates binding to human receptor but restricts binding to avian receptor. Both features probably contribute to the acquisition of transmissibility by this mutant virus.

PMID:
23615615
[PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/pubmed/23615615
 
Re: Nature - Receptor binding by a ferret-transmissible H5 avian influenza virus

http://www.flutrackers.com/forum/showthread.php?t=204618

http://www.nature.com/nature/journal/vaop/ncurrent/pdf/nature12144.pdf

also talked about in TWiV 230
http://traffic.libsyn.com/twiv/TWiV230.mp3

42:00-1:08:00 = 26min

> in the same folded-back conformation as seen for HA from the 1918, 1957 (ref. 4), 1968 (ref. 5)
> and 2009 (ref. 6) pandemic viruses

do they want to suggest it has the same pandemic potential as these viruses ?
Nobody knows... but apparently they want us to wonder about that

I wonder what other, non-pandemic viruses bind in that conformation
equine H3N8 ? euroswine H1N1 ? extinct equine H7N7 ? poultry H9N2 with Q234L ?


2 procedures to quantify receptor binding affinity and specifity
5fold weaker to human receptors than A/Aichi/2/1968
10fold weaker to avian receptors than Aichi


------------------------------------------------
CIDRAP-article: http://www.cidrap.umn.edu/cidrap/content/influenza/avianflu/news/apr2513receptor.html
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other new paper about H5 receptor binding: http://www.ncbi.nlm.nih.gov/pubmed/23486663
 
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