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Method for Measurement of Viral Fusion Kinetics at the Single Particle Level
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Estructura de la proteína de la envoltura del virus del dengue después de la fusión de la membrana
Yorgo Modis1, Steven Ogata, David Clements
1Howard Hughes Medical Institute, Children's Hospital and Harvard Medical School, 320 Longwood Avenue, Boston, Massachusetts 02115, USA.
Nature
|January 23, 2004
Resumen
El virus del dengue utiliza su envolvente glicoproteína E para fusionarse con las células huésped. El análisis estructural revela un estado postfusión con bucles de fusión que facilitan la inserción de la membrana, lo que sugiere nuevas estrategias antivirales.
Área de la Ciencia:
- Virología Virología.
- Biología Estructural Biología estructural.
- Biología Molecular Biología Molecular
Sus antecedentes:
- El virus del dengue infecta las células del huésped a través de su envolvente glicoproteína E.
- La entrada viral implica cambios conformacionales en la glicoproteína E desencadenados por el pH endosómico.
- Comprender estos cambios es crucial para el desarrollo de terapias antivirales.
Objetivo del estudio:
- Determinar la estructura tridimensional del ectodominio E soluble (sE) del virus del dengue en su estado postfusión.
- Para modelar el mecanismo de la fusión de la membrana viral con el huésped.
- Identificar objetivos potenciales para inhibir la entrada del flavivirus.
Principales métodos:
- Cristalografía de rayos X para determinar la estructura del trímero, después de la fusión s.E.
- Análisis estructural y comparación con la forma dimérica, prefusión.
- Modelado de la interacción del bucle de fusión con las bicapas lipídicas.
Principales resultados:
- El ectodominio SE postfusión adopta una estructura trímera alargada, distinta de la forma de prefusión dimérica.
- Tres "bucles de fusión" están expuestos en un extremo del trimer para la inserción de la membrana de la célula huésped.
- La estructura revela una conformación "doblada hacia atrás", dirigiendo el extremo carboxílico hacia los bucles de fusión.
Conclusiones:
- Se propone un mecanismo de fusión impulsado por cambios conformacionales irreversibles en la glicoproteína E.
- La inserción del bucle de fusión en la bicapa lipídica es un paso clave facilitado por la estructura plegada.
- Las características estructurales específicas ofrecen estrategias potenciales para inhibir la entrada del flavivirus.
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