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Flexibilidad de la esfera de coordinación de los modelos de sitio activo para la hidrogenasa Fe-solo: estudios en el
E J Lyon1, I P Georgakaki, J H Reibenspies
1Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
Journal of the American Chemical Society
|July 18, 2001
Resumen
Los complejos de hierro dinucleares con puentes de azufre exhiben un comportamiento fluxional y un intercambio intramolecular de CO. Estas características son cruciales para comprender los mecanismos de activación del hidrógeno en las enzimas.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Química bioorgánica Química bioorgánica.
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- Las hidrogenasas de solo Fe son enzimas cruciales para el metabolismo de H2.
- Comprender las características estructurales y dinámicas de los complejos de hierro puede proporcionar información sobre los mecanismos de las enzimas.
Objetivo del estudio:
- Para sintetizar y caracterizar complejos de hierro dinuclear con diferentes puentes de azufre.
- Investigar la relación entre la estructura compleja, la dinámica y la relevancia potencial para los sitios activos de la hidrogenasa Fe-only.
Principales métodos:
- Espectroscopia de resonancia magnética nuclear (RMN) de protones y carbono-13 con temperatura variable. espectroscopia de resonancia magnética nuclear (RMN).
- Estudios cinéticos de las reacciones de intercambio de ligandos.
- Cálculos de la Teoría Funcional de la Densidad (DFT).
Principales resultados:
- Se sintetizaron complejos de hierro dinucleares con ditioalcano y puentes de ditioarilo.
- Los estudios de RMN revelaron fluxionalidad en algunos complejos y intercambio intramolecular de sitios de CO.
- Los estudios cinéticos demostraron la formación selectiva de dicianodianiones a través de mecanismos asociativos.
- Los cálculos de DFT proporcionaron información sobre la dinámica intramolecular y la cooperatividad en el intercambio de ligandos.
Conclusiones:
- Los complejos de hierro dinuclear sintetizados imitan ciertos aspectos de los sitios activos de la hidrogenasa Fe-only.
- La dinámica observada y los mecanismos de intercambio de ligandos ofrecen un modelo para comprender la activación/producción de H2.
- El movimiento de bisagra del puente de azufre es una característica clave relacionada con la actividad enzimática.
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