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El dominio LOV2 de la fototropina: un conmutador fotocrómico reversible
John T M Kennis1, Ivo H M van Stokkum, Sean Crosson
1Department of Biophysics, Faculty of Sciences, Vrije Universiteit, 1081HV Amsterdam, The Netherlands. j.kennis@few.vu.nl
Journal of the American Chemical Society
|April 9, 2004
Resumen
Los dominios de luz, oxígeno o voltaje (LOV) son proteínas sensibles a la luz azul. La espectroscopia ultra rápida revela que el dominio LOV2 actúa como un interruptor fotocrómico reversible, activado por la luz azul y desactivado por la luz UV cercana.
Área de la Ciencia:
- Fotobiología Fotobiología.
- Ciencia de las proteínas Ciencia de las proteínas.
- La biofísica es la biofísica.
Sus antecedentes:
- Los dominios de luz, oxígeno o voltaje (LOV) son fotorreceptores de luz azul.
- Utilizan un cromóforo flavin para la sensibilidad a la luz.
- El dominio LOV2 forma un adducto covalente a la absorción de la luz azul.
Objetivo del estudio:
- Para investigar la foto-reactividad del estado de adducto covalente del dominio LOV2.
- Determinar el mecanismo y la escala de tiempo de la reformación de la obligación adyutiva.
- Para establecer el comportamiento del conmutador fotocrómico del dominio LOV2.
Principales métodos:
- Espectroscopia ultrarrápida aplicada al adducto covalente fotoacumulado de LOV2.2.
- Se estudió la absorción de fotones cercanos al UV por el estado adducto.
- Análisis con resolución temporal de la dinámica de los enlaces covalentes.
Principales resultados:
- La absorción de luz UV cercana desencadena una ruptura ultra rápida (100 ps) del enlace covalente.
- El estado básico sensible a la luz azul se recupera rápidamente.
- Demostración de la conmutación fotocrómica reversible en el dominio LOV2.
Conclusiones:
- El dominio LOV2 funciona como un interruptor fotocrómico reversible.
- La luz azul activa el interruptor formando un adducto covalente.
- La luz UV cercana desactiva el interruptor rompiendo el enlace de adducción.
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