The ultrafast photoisomerizations of rhodopsin and bathorhodopsin are modulated by bond length alternation and HOOP driven electronic effects.
J Am Chem Soc
; 133(10): 3354-64, 2011 Mar 16.
Article
em En
| MEDLINE
| ID: mdl-21341699
ABSTRACT
Rhodopsin (Rh) and bathorhodopsin (bathoRh) quantum-mechanics/molecular-mechanics models based on ab initio multiconfigurational wave functions are employed to look at the light induced π-bond breaking and reconstitution occurring during the Rh â bathoRh and bathoRh â Rh isomerizations. More specifically, semiclassical trajectory computations are used to compare the excited (S(1)) and ground (S(0)) state dynamics characterizing the opposite steps of the Rh/bathoRh photochromic cycle during the first 200 fs following photoexcitation. We show that the information contained in these data provide an unprecedented insight into the sub-picosecond π-bond reconstitution process which is at the basis of the reactivity of the protein embedded 11-cis and all-trans retinal chromophores. More specifically, the data point to the phase and amplitude of the skeletal bond length alternation stretching mode as the key factor switching the chromophore to a bonding state. It is also confirmed/found that the phase and amplitude of the hydrogen-out-of-plane mode controls the stereochemical outcome of the forward and reverse photoisomerizations.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Rodopsina
/
Luz
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos