TY  - JOUR
A1  - Mondal, Padmabati
A1  - Granucci, Giovanni
A1  - Rastädter, Dominique
A1  - Persico, Maurizio
A1  - Burghardt, Irene
T1  - Azobenzene as a photoregulator covalently attached to RNA : a quantum mechanics/molecular mechanics-surface hopping dynamics study
T2  - Chemical science
N2  - The photoregulation of nucleic acids by azobenzene photoswitches has recently attracted considerable interest in the context of emerging biotechnological applications. To understand the mechanism of photoinduced isomerisation and conformational control in these complex biological environments, we employ a Quantum Mechanics/Molecular Mechanics (QM/MM) approach in conjunction with nonadiabatic Surface Hopping (SH) dynamics. Two representative RNA–azobenzene complexes are investigated, both of which contain the azobenzene chromophore covalently attached to an RNA double strand via a β-deoxyribose linker. Due to the pronounced constraints of the local RNA environment, it is found that trans-to-cis isomerization is slowed down to a time scale of ∼10–15 picoseconds, in contrast to 500 femtoseconds in vacuo, with a quantum yield reduced by a factor of two. By contrast, cis-to-trans isomerization remains in a sub-picosecond regime. A volume-conserving isomerization mechanism is found, similarly to the pedal-like mechanism previously identified for azobenzene in solution phase. Strikingly, the chiral RNA environment induces opposite right-handed and left-handed helicities of the ground-state cis-azobenzene chromophore in the two RNA–azobenzene complexes, along with an almost completely chirality conserving photochemical pathway for these helical enantiomers.
Y1  - 2018
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/46824
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-468248
SN  - 2041-6539
SN  - 2041-6520
N1  - This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.
VL  - 9
IS  - 20
SP  - 4671
EP  - 1681
PB  - RSC
CY  - Cambridge
ER  -