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Accueil > Animation Scientifique > Année 2014

Séminaire TMS Dr. Marco Marazzi

Séminaire TMS. Mercredi 15 octobre 2014, 11h, Salle Jean Barriol, Vandoeuvre-lès-Nancy.
"Effects of Peptide Induced Forces on the Photochemistry of a Retinal-like Switch"
Dr. Marco Marazzi,
Department of Theoretical Chemical Biology, Karlsruhe, Germany

Authors : Marco Marazzi,1 Cristina García-Iriepa,2,3 Diego Sampedro,2 Luis Manuel Frutos,3 Marcus Elstner1
1 Department of Theoretical Chemical Biology, Institute of Physical Chemistry, KIT, Kaiserstrasse 12, 76131 Karlsruhe, Germany
2 Departamento de Química, Universidad de La Rioja, Madre de Dios 54, 26006 Logroño, Spain
3 Departmento de Química Analitica, Química Física e Ingeniería Química, Universidad de Alcalá, 28871 Alcalá de Henares, Spain
The control of biomolecular systems can be achieved through the application of photoswitches. Especially, a retinal like photoswitch based on E/Z photoisomerization was experimentally shown to be a relevant candidate for reversible control of the alpha helix peptide conformation [1].
Here, starting from photon absorption carried by the switch, we focus on the understanding of the whole mechanism leading to the final response of the peptide conformation. More in detail, molecular dynamics simulations were performed for the E- and Z-isomer linked peptide, as well as for the unlinked peptide, in order to reveal the overall conformational changes induced by the attachment of the photoswitch. Our results, supported by circular dichroism spectroscopy [1], show on average how the unlinked peptide is partially unfolded in water, whether the E-isomer linked peptide tends to increase the helical content, and the Z-isomer linked peptide produces peptide bending possibly leading to an alpha hairpin conformation.
[1] M. Blanco-Lomas, S. Samanta, P. J. Campos, G. A. Woolley, D. Sampedro, J. Am. Chem. Soc., 2012, 134, 6960–6963.