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La disociación por captura de electrones se produce con un bajo grado de migración intramolecular de hidrógenos de
Kasper D Rand1, Christopher M Adams, Roman A Zubarev
1Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
Journal of the American Chemical Society
|January 4, 2008
Resumen
La disociación por captura de electrones (ECD) minimiza la mezcla de hidrógeno en el análisis de proteínas en fase gaseosa. Este método determina con precisión los niveles de deuterio, lo que permite la resolución de un solo residuo en los estudios de espectrometría de masas de intercambio de deuterio con hidrógeno (HX-MS).
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Química analítica Química analítica es la que
- Biología Estructural Biología estructural.
Sus antecedentes:
- La espectrometría de masas de intercambio de deuterio de hidrógeno (HX-MS) analiza la dinámica de las proteínas.
- Los métodos actuales para la localización del deuterio están limitados en la resolución de residuos.
- La fragmentación de la fase gaseosa es clave para mejorar la aplicabilidad de HX-MS.
Objetivo del estudio:
- Para evaluar la migración de hidrógeno intramolecular durante la disociación de captura de electrones (ECD).
- Evaluar el potencial del ECD para la determinación del nivel de deuterio específico del sitio en péptidos.
- Para comparar la ECD con la disociación inducida por colisión (CID) para preservar el etiquetado de deuterio.
Principales métodos:
- Se investigó la migración intramolecular de hidrógeno (1H/2H) utilizando péptidos etiquetados selectivamente con deuterio.
- Utilizó la disociación por captura de electrones (ECD) y la disociación inducida por colisión (CID) para la fragmentación en fase gaseosa.
- Los iones del fragmento c y z analizados para patrones de incorporación de deuterio.
Principales resultados:
- La excitación vibratoria minimizada durante el ECD resultó en una mezcla limitada de hidrógeno.
- La excesiva excitación vibratoria o CID condujo a una extensa mezcla de hidrógeno.
- Los iones de fragmentos generados por ECD reflejaron con precisión los patrones de etiquetado de deuterio en la fase de solución.
Conclusiones:
- El ECD es un método prometedor para el análisis de deuterio específico del sitio en HX-MS.
- El ECD supera las limitaciones de los métodos tradicionales de fragmentación al reducir la migración de hidrógeno.
- Esta técnica facilita la resolución de un solo residuo para el análisis de la dinámica estructural de las proteínas.
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