Berlin 2012 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 26: Posters: Membranes and Vesicles
BP 26.13: Poster
Donnerstag, 29. März 2012, 17:30–19:30, Poster A
Unpacking the influenza virus at low pH — •Sai Li1, Frederic Eghiaian1, Christian Sieben2, Andreas Herrmann2, and Iwan Schaap1 — 1Drittes Physikalisches Institut, Georg-August-Universität, Göttingen — 2Institut für Biologie, Humboldt-Universität zu Berlin, Berlin
The genome of the influenza virus is enveloped in a shell made out of a lipid bilayer which inside is covered by a layer of M1 matrix protein. During infection the virus is taken up in the endosomes of the target cell. For the release of the genome the viral composite shell must undergo large conformational changes to allow for membrane fusion with the host-cell endosome. We performed AFM indentation experiments under conditions that mimicked the gradual acidification from early to late endosomes, and we have found that the softening the viral envelope starts as early as at pH 6 and is completed at pH 5.5. We propose that this softening is related to the irreversible destabilization of the M1 layer. In addition, membrane fusion being enhanced after pre-incubation of viruses at pH6, we speculate that stripping the M1 matrix off the lipid envelope during an exposure to this intermediate pH of early endosomes is essential to achieve efficient infection.