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Las bicapas lipídicas modulan significativamente la fibrilación cruzada de dos péptidos amiloidogénicos distintos
Noga Gal1, Ahiud Morag, Sofiya Kolusheva
1Department of Chemistry, Ben Gurion University of the Negev , Beer Sheva, Israel 84105.
Journal of the American Chemical Society
|August 20, 2013
Resumen
Las proteínas mal plegadas forman placas amiloides en enfermedades como el Alzheimer. Este estudio muestra que los péptidos amiloides no relacionados, el polipéptido amiloide de islotes (IAPP) y la proteína priónica (PrP), interactúan en las membranas, alterando la fibrilación y la patogenicidad.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- La neurociencia es la neurociencia.
Sus antecedentes:
- Las placas amiloides de proteínas mal plegadas son características de enfermedades incurables como el Alzheimer y la diabetes tipo II.
- La hipótesis priónica sugiere que las semillas de proteínas mal plegadas propagan la agregación, actuando como agentes infecciosos.
- Las interacciones entre diferentes péptidos amiloides pueden influir en las vías de fibrilación y la gravedad de la enfermedad.
Objetivo del estudio:
- Para investigar la vía de fibrilación de dos péptidos amiloidogénicos estructural y fisiológicamente no relacionados: el polipéptido amiloide de islotes (IAPP) y un determinante de proteína priónica (PrP).
- Determinar el papel de las bicapas de membrana en la modulación de la interacción y agregación de estos péptidos dispares.
- Explorar cómo la fibrilación cruzada afecta los perfiles de interacción de la membrana y las propiedades biofísicas de los agregados amiloides.
Principales métodos:
- Incubación de péptidos IAPP y PrP juntos en presencia de bicapas de membrana.
- Análisis de las vías de fibrilación y la formación de distintas especies fibrilares.
- Caracterización de los perfiles de interacción de membrana de las especies de péptidos de fibrilación cruzada.
Principales resultados:
- El ambiente de la bicapa lipídica influye significativamente en la vía de fibrilación de IAPP y PrP cuando se incuban juntos.
- Se ensamblan distintas especies fibrilares morfológicamente diferentes en presencia de membranas.
- La fibrilación cruzada conduce a perfiles de interacción de membrana alterados en comparación con la agregación separada.
Conclusiones:
- Las membranas actúan como medios críticos superficiales activos que promueven las interacciones entre péptidos amiloidogénicos no relacionados.
- La fibrilación cruzada inducida por membrana modula tanto las vías de fibrilación como las propiedades biofísicas de los agregados péptidos.
- Este proceso puede desempeñar un papel importante en las patologías moleculares de las enfermedades de plegamiento incorrecto de proteínas.
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