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Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
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Movimiento de transferencia de gran amplitud de protones en exceso hidratados mapeado por espectroscopia de
Fabian Dahms1, Benjamin P Fingerhut1, Erik T J Nibbering1
1Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Berlin 12489, Germany.
Science (New York, N.Y.)
|July 15, 2017
Resumen
La dinámica de protones ultrarrápidos en el agua revela que las geometrías catiónicas de Zundel son cruciales para la solución y el transporte de protones. Los protones exploran rápidamente múltiples posiciones en femtosegundos, influenciados por los campos eléctricos ambientales y los movimientos de enlaces de hidrógeno.
Área de la Ciencia:
- Química Física
- Espectroscopia
- Biofísica y Química
Sus antecedentes:
- La disolución y el transporte de protones son fundamentales para la química ácido-base y los procesos biológicos.
- La comprensión de la dinámica de protones ultrarrápidos es clave para dilucidar estos mecanismos.
Objetivo del estudio:
- Para mapear las excursiones de protones ultrarrápidos a lo largo de las coordenadas de transferencia de protones.
- Investigar el papel de las geometrías catiónicas de Zundel en la solución y el transporte de protones.
Principales métodos:
- Se empleó espectroscopia infrarroja bidimensional (2D IR).
- Los experimentos se llevaron a cabo en agua a granel y en un catión Zundel (H5O2) + preparado selectivamente en acetonitrilo.
Principales resultados:
- Se observó que los protones exploraban múltiples posiciones dentro de escalas de tiempo inferiores a 100 femtosegundos.
- Las vibraciones de transferencia de protones mostraron una fuerte amortiguación con una desintegración de población de 20 a 40 femtosegundos.
- Se encontró que los campos eléctricos ambientales y los movimientos de enlaces de hidrógeno inducen fluctuaciones potenciales.
Conclusiones:
- Las geometrías tipo Zundel juegan un papel central en la solución y el transporte de protones acuosos.
- Las dinámicas ultra rápidas están significativamente influenciadas por el entorno de hidratación local.
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