The implementation of multiconfigurational quantum chemistry methods into a quantum-mechanics/molecular-mechanics protocol has allowed the construction of a realistic computer model for the sensory rhodopsin of the cyanobacterium Anabaena PCC 7120. The model, which reproduces the absorption spectra of both the all-trans and 13-cis forms of the protein and their associated K and L intermediates, is employed to investigate the light-driven steps of the photochromic cycle exhibited by the protein. It is found that the photoisomerizations of the all-trans and 13-cis retinal chromophores occur through unidirectional, counterclockwise 180° rotations of the ! C14 " C15 ! moiety with respect to the Lys210- linked end of the chromophore axis. Thus, the sequential interconversions of the all-trans and 13-cis forms during a single photochromic cycle yield a complete (360°) unidirectional rotation of the ! C14 " C15 ! moiety. This finding implies that Anabaena sensory rhodopsin is a biological realization of a light-driven molecular rotor.

Strambi, A., Durbeij, B., Ferré, N., Olivucci, M. (2010). Anabaena sensory rhodopsin is a light-driven unidirectional rotor. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 107(50), 21322-21326 [10.1073/pnas.1015085107].

Anabaena sensory rhodopsin is a light-driven unidirectional rotor

OLIVUCCI, MASSIMO
2010-01-01

Abstract

The implementation of multiconfigurational quantum chemistry methods into a quantum-mechanics/molecular-mechanics protocol has allowed the construction of a realistic computer model for the sensory rhodopsin of the cyanobacterium Anabaena PCC 7120. The model, which reproduces the absorption spectra of both the all-trans and 13-cis forms of the protein and their associated K and L intermediates, is employed to investigate the light-driven steps of the photochromic cycle exhibited by the protein. It is found that the photoisomerizations of the all-trans and 13-cis retinal chromophores occur through unidirectional, counterclockwise 180° rotations of the ! C14 " C15 ! moiety with respect to the Lys210- linked end of the chromophore axis. Thus, the sequential interconversions of the all-trans and 13-cis forms during a single photochromic cycle yield a complete (360°) unidirectional rotation of the ! C14 " C15 ! moiety. This finding implies that Anabaena sensory rhodopsin is a biological realization of a light-driven molecular rotor.
2010
Strambi, A., Durbeij, B., Ferré, N., Olivucci, M. (2010). Anabaena sensory rhodopsin is a light-driven unidirectional rotor. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 107(50), 21322-21326 [10.1073/pnas.1015085107].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/8047
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