Environment effects on triplet-triplet energy transfer in DNA

We present a quantum-chemical study of the impact of the environment on triplet exciton migration in polyA-polyT DNA sequences. Electronic couplings are estimated by combining the fragment excitation difference scheme with the polarizable continuum model. Conformational fluctuations are taken into a...

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Detalles Bibliográficos
Autores: Curutchet Barat, Carles E., Voityuk, Alexander A.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2011
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/175505
Acceso en línea:https://hdl.handle.net/2445/175505
Access Level:acceso abierto
Palabra clave:Transferència d'energia
ADN
Química quàntica
Medi ambient
Energy transfer
DNA
Quantum chemistry
Natural environment
Descripción
Sumario:We present a quantum-chemical study of the impact of the environment on triplet exciton migration in polyA-polyT DNA sequences. Electronic couplings are estimated by combining the fragment excitation difference scheme with the polarizable continuum model. Conformational fluctuations are taken into account by considering 500 structures extracted from a classical molecular dynamics trajectory. In contrast to singlet transfer, we find that the environment effect is not strongly correlated with the coupling magnitude in vacuum, and can significantly enhance or reduce its value in individual conformations. Conformational averaging, however, leads to a net cancellation of medium effects on the overall transfer rate.