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Fusión estructural de un dímero de aminoácidos en el cruce entre sistemas

Ulrich J Lorenz¹, Thomas R Rizzo

¹Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland.

Journal of the American Chemical Society

|September 25, 2014

Resumen

Se estudió la dinámica del estado excitado de los dímeros de fenilalanina/serina protonados. El cruce intersistémico del estado S1 al T1 conduce a una estructura fundida, explorando la superficie de energía potencial.

Área de la Ciencia:

Química Física es la química física.
La espectroscopia es una técnica de espectroscopia.
La Dinámica Química es la Dinámica Química.

Sus antecedentes:

Comprender la dinámica del estado excitado es crucial para los procesos moleculares.
Los dímeros de aminoácidos protonados ofrecen información sobre las interacciones biomoleculares.

Objetivo del estudio:

Para investigar la dinámica del estado excitado de la fenilalanina (Phe) /serina (Ser) dimer protonado.
Para dilucidar la evolución estructural y el paisaje energético después de la fotoexcitación.

Principales métodos:

Excitación del láser ultravioleta (UV) al estado S1.
Proyección de infrarrojos (IR) de los modos de vibración.
Espectroscopia de resolución temporal para monitorear la dinámica.

Principales resultados:

El estado S1 exhibe una vida útil de aproximadamente 70 ns.
Se observó el cruce intersistémico (ISC) al estado T1.
La evolución estructural indica la exploración de la superficie de energía potencial (PES) después de ISC, lo que lleva a una estructura fundida.

Conclusiones:

La vida útil del estado S1 y la vía ISC son clave para la dinámica del dímero.
La superación de las barreras de isomerización a través del aumento de la energía vibratoria impulsa la exploración estructural.
El dímero protonado Phe/Ser adopta una estructura fundida en el estado T1.

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