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Migración intramolecular de hidrógenos amidales en péptidos protonados tras la activación de colisión
Thomas J D Jørgensen1, Henrik Gårdsvoll, Michael Ploug
1Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark. tjdj@bmb.sdu.dk
Journal of the American Chemical Society
|February 24, 2005
Resumen
Los péptidos protonados gaseosos se someten a una mezcla completa de hidrógeno y amida durante la activación de colisión. Este hallazgo es crucial para interpretar los datos de espectrometría de masas en tándem de los experimentos de etiquetado de deuterio.
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:
- Se debate el grado de mezcla de hidrógeno amida en péptidos protonados tras la activación de colisión.
- La información precisa específica del sitio de los experimentos de intercambio de deuterio se basa en un mínimo de codificación.
Objetivo del estudio:
- Para investigar la migración de hidrógeno de amida intramolecular en péptidos durante la activación de colisión de baja energía.
- Para determinar el grado de mezcla de hidrógeno en iones péptidos gaseosos.
Principales métodos:
- Se utilizaron péptidos etiquetados con deuterio regioselectivamente con distintas regiones de unión y no unión.
- Se generaron péptidos etiquetados a través de complejos de receptores de larga vida y se confirmó la regioselectividad de etiquetado a través de la proteólisis de la pepsina.
- Se analizaron los iones fragmentos (iones b- y y) de la disociación inducida por colisión (CID) utilizando la espectrometría de masas Q-TOF ESI.
Principales resultados:
- El contenido de deuterio en los iones fragmentos coincidía estrechamente con los valores teóricos para el 100% de revuelo.
- Se observó una completa aleatorización de los átomos de hidrógeno unidos al nitrógeno y al oxígeno.
Conclusiones:
- La disociación inducida por colisión (CID) de péptidos protonados gaseosos conduce a una mezcla completa de hidrógenos amidales.
- Esta codificación completa debe tenerse en cuenta al interpretar los datos de espectrometría de masas en tándem para estudios de intercambio de hidrógeno / deuterio específicos del sitio.
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