Simulating the Electronic Circular Dichroism Spectra of Photoreversible Peptide Conformations

  1. Gattuso, H. 23
  2. García-Iriepa, C. 14
  3. Sampedro, D. 1
  4. Monari, A. 23
  5. Marazzi, M. 23
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

  2. 2 Centre National de la Recherche Scientifique
    info

    Centre National de la Recherche Scientifique

    París, Francia

    ROR https://ror.org/02feahw73

  3. 3 University of Lorraine
    info

    University of Lorraine

    Nancy, Francia

    ROR https://ror.org/04vfs2w97

  4. 4 Universidad de Alcalá
    info

    Universidad de Alcalá

    Alcalá de Henares, España

    ROR https://ror.org/04pmn0e78

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Revista:
Journal of Chemical Theory and Computation

ISSN: 1549-9618

Any de publicació: 2017

Volum: 13

Número: 7

Pàgines: 3290-3296

Tipus: Article

DOI: 10.1021/ACS.JCTC.7B00163 SCOPUS: 2-s2.0-85023176688 WoS: WOS:000405535600019 GOOGLE SCHOLAR

Altres publicacions en: Journal of Chemical Theory and Computation

Objectius de Desenvolupament Sostenible

Resum

Electronic circular dichroism (CD) spectroscopy of peptides is one of the most important experimental characterization tools to get insights regarding their structure. Nevertheless, even though highly useful, the reliable simulations of CD spectra result in a complex task. Here, we propose a combination of quantum mechanics/molecular mechanics (QM/MM) methods with a semiempirical Hamiltonian based on the Frenkel excitons theory to efficiently describe the behavior of a model 27-amino acid α-helical peptide in water. Especially, we show how the choice of the QM region, including different possible hydrogen-bonding patterns, can substantially change the final CD spectrum shape. Moreover, we prove that our approach can correctly explain the changes observed in the peptide conformation (from α-helix to α-hairpin) when covalently linked to a protonated retinal-like molecular switch and exposing the system to UVA light, as previously observed by experiment and extensive molecular dynamics. Hence our protocol may be straightforwardly exploited to characterize light-induced conformation changes in photoactive materials and more generally protein folding processes. © 2017 American Chemical Society.