[Lcefiec] SEMINARIOS QB-IQUIBICEN- MARTES 19 feb- Invitados Especiales

[Cybele García]

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Estimados Colegas,

abriendo el ciclo de seminarios QB 2013, los invitamos a participar del
seminario que tendrá lugar en el Aula Cardini el próximo MARTES 19 de
febrero a las 14:30 hs:

*Influenza virus binds to its host cell through multiple dynamic
interactions. A single force spectroscopy and force probe MD simulation
study*

a cargo del Prof. Dr. Andreas Herrmann-

Humboldt-Universität zu Berlin
Institut für Biologie
Molekulare Biophysik
Invalidenstr. 42
D-10115 Berlin, Germany
Email: andreas.herrmann at rz.hu-berlin.de


Influenza virus belongs to a wide range of enveloped viruses. Virus-host
cell binding marks the first critical step of infection. Hence, forces
involved in this process are essential. The major spike protein
hemagglutinin binds sialic acid residues of glycoproteins and lipids with
dissociation constants in the millimolar range (Sauter et al. (1992)
Biochemistry 31:9609–9621), indicating a multivalent binding mode. We
characterized the attachment of influenza virus to host cell receptors
using three independent approaches. Optical tweezers and atomic force
microscopy-based single molecule force spectroscopy provides powerful
tools to measure binding forces in biological systems. Optical tweezers
and AFM-based single molecule force spectroscopy revealed very low
interaction forces.  The observation of sequential unbinding events
strongly suggests a multivalent binding mode between virus and cell
membrane. However, an assignment of forces to their underlying molecular
interactions involved in these processes is difficult or even cannot be
obtained by these techniques. In molecular dynamics, time-dependent
interactions between all atoms within a given system are calculated
numerically within timescales smaller than those observed in biological
phenomena. Force probe molecular dynamics simulations provide a way to
overcome this time limitation by introducing a moving harmonic potential
as a "virtual spring" acting on given atoms. Molecular dynamics
simulations reveal a variety of unbinding pathways that indicate a highly
dynamic interaction between HA and its receptor allowing to rationalize
the binding of influenza virus to host cells quantitatively at molecular
level.



Invita LFBM
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Los esperamos!
Adriana De Siervi
Javier Cotignola
Cybele García






















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