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La disociación por captura de electrones de iones negativos: fragmentación impulsada por radicales de aniones
Hyun Ju Yoo1, Ning Wang, Shuyi Zhuang
1Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA.
Journal of the American Chemical Society
|September 28, 2011
Resumen
Los investigadores desarrollaron la disociación de captura de electrones de iones negativos (niECD), una nueva técnica de espectrometría de masas. Este método permite el análisis de péptidos y proteínas ácidas, que son un desafío para los métodos existentes.
Área de la Ciencia:
- Química analítica Química analítica es la que
- La bioquímica es la bioquímica.
- Espectrometría de masas por espectrometría de masas.
Sus antecedentes:
- Los polianiones gaseosos con barreras de Coulomb son de interés, pero no se han informado para los aniones biológicos.
- La unión de electrones a los cationes de péptidos y proteínas es útil para la espectrometría de masas en tándem (MS/MS).
- Los métodos existentes como la disociación por captura de electrones (ECD) y la disociación por transferencia de electrones (ETD) son efectivos para los cationes, pero no son ideales para los aniones ácidos.
Objetivo del estudio:
- Para investigar la captura de electrones por aniones péptidos.
- Desarrollar una nueva técnica MS/MS para el análisis de péptidos y proteínas ácidas.
- Para explorar el mecanismo de disociación después de la captura de electrones en modo de iones negativos.
Principales métodos:
- Adhesión de electrones a los aniones péptidos ([M - nH](n-)) dentro de un rango de energía específico (3,5-6,5 eV).
- Análisis de los radicales intermedios con carga aumentada formados después de la captura de electrones.
- Investigación de los patrones de disociación análogos a las ECD/ETD.
Principales resultados:
- Los aniones péptidos capturan electrones, formando radicales intermedios que se disocian.
- La disociación es análoga a la ECD/ETD, produciendo iones producto predecibles.
- Las estructuras zwitteriónicas de fase gaseosa están implicadas en el nuevo proceso de disociación de captura de electrones de iones negativos (niECD).
Conclusiones:
- La disociación de captura de electrones de iones negativos (niECD) es una técnica viable de MS/MS.
- niECD es particularmente útil para analizar péptidos y proteínas ácidas, incluidas aquellas con modificaciones post-traducionales.
- Este método amplía la aplicabilidad de la disociación basada en electrones en la espectrometría de masas para muestras biológicas.
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