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Adictos de peróxido de tirosina-lípido de terminación radical: para acoplamiento y ciclización intramolecular de
Roman Shchepin1, Matias N Möller, Hye-young H Kim
1Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, USA.
Journal of the American Chemical Society
|November 25, 2010
Resumen
Las reacciones de los radicales libres forman nuevos adductos lípido-tirosina. Estos aductos se someten a ciclización, creando potenciales enlaces cruzados de proteínas relevantes para el estrés oxidativo.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Química orgánica es la química orgánica.
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- La peroxidación lipídica es un proceso clave en el daño oxidativo.
- Los residuos de tirosina en las proteínas son susceptibles a la modificación oxidativa.
- La comprensión de los adductos de lípidos y proteínas es crucial para el estudio del estrés oxidativo.
Objetivo del estudio:
- Para investigar la co-oxidación de lípidos poliinsaturados con tirosina.
- Para caracterizar la estructura de los nuevos aductos de peróxido lipídico y tirosina.
- Para dilucidar los mecanismos de reacción y los productos formados.
Principales métodos:
- Espectroscopia de RMN 1D y 2D para elucidación estructural.
- Espectrometría de masas (EM) para la identificación y caracterización de adductos.
- Estudios cinéticos para determinar las velocidades de reacción y los parámetros de activación.
Principales resultados:
- Se formaron y caracterizaron nuevos adductos lipídicos peróxido-tirosina (fenol).
- Los adductos se forman exclusivamente en la posición para de los radicales de tirosina.
- La ciclización intramolecular Diels-Alder (IMDA) produjo aductos tricíclicos.
- La reducción de iones de cobre de los adutos primarios produjo productos específicos de dienona.
Conclusiones:
- Los radicales peroxilo de lípidos se unen con los radicales tirosilo para formar aductos de ciclohexadienona.
- Estos adductos pueden someterse a reacciones adicionales, incluida la ciclización IMDA.
- Los hallazgos proporcionan un marco para comprender el enlace cruzado lípido-proteína en escenarios de estrés oxidativo.
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