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Updated: Jun 27, 2026
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Synthesis and Mass Spectrometry Analysis of Oligo-peptoids
Published on: February 21, 2018
Las vías de fragmentación de fragmentación de secuencia de los péptidos protonados
Christian Bleiholder1, Sandra Osburn, Todd D Williams
1Department of Molecular Biophysics, Im Neuenheimer Feld 580, German Cancer Research Center, 69120 Heidelberg, Germany.
Journal of the American Chemical Society
|December 6, 2008
Resumen
La disociación inducida por colisión (CID) de los fragmentos de péptidos revela que los iones b ciclizan rápidamente, lo que lleva a patrones de fragmentación determinados por el isómero cíclico. Este mecanismo de reapertura de ciclización puede causar la pérdida de información de la secuencia durante el análisis de péptidos.
Área de la Ciencia:
- Química Analítica La Química Analítica es la
- Química computacional es la química computacional.
- La bioquímica es la bioquímica.
Sus antecedentes:
- Comprender la fragmentación de péptidos en la espectrometría de masas es crucial para la determinación de la secuencia.
- La disociación inducida por colisión (CID) es una técnica común para la fragmentación de péptidos.
- El comportamiento de los iones N-terminales b y a durante la CID puede ser complejo, implicando reorganizaciones.
Objetivo del estudio:
- Para investigar las estructuras de la fase gaseosa y las vías de fragmentación de N-terminal b y un fragmentos de péptidos específicos.
- Para dilucidar los mecanismos de las reacciones de reordenamiento y reordenamiento durante el CID de iones b y a.
- Determinar la influencia de la ciclización en los patrones de fragmentación del CID.
Principales métodos:
- Investigación experimental utilizando la disociación inducida por colisión (CID).
- Análisis teórico utilizando cálculos de mecánica molecular y teoría funcional de la densidad (DFT).
- Comparación de patrones de fragmentación para isómeros de péptidos lineales y cíclicos.
Principales resultados:
- CID de baja energía de b(5) fragmentos de varios péptidos arrojaron patrones de disociación similares.
- CID de protonado cyclo- ((YAGFL) produjo idénticos fragmentos y abundancias de iones como lineal b ((5) iones, lo que sugiere una rápida ciclización.
- Los resultados computacionales apoyaron un mecanismo de reapertura de la ciclización, con el ciclo-YAGFL protonado siendo energéticamente favorecido sobre los isómeros lineales.
Conclusiones:
- Los espectros de fragmentación de los iones b(5) lineales están dominados por sus isómeros cíclicos debido a su rápida ciclización y fácil interconversión.
- Este mecanismo de reapertura de ciclización puede conducir a una pérdida completa de la información de la secuencia durante el CID.
- El CID de a(5) iones implica reorganizaciones de tipo b y de tipo a --> a*, con ciclización seguida de reapertura a la estructura lineal.
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