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Characterizing Individual Protein Aggregates by Infrared Nanospectroscopy and Atomic Force Microscopy
Published on: September 12, 2019
El polimorfismo de las fibrillas amiloides está bajo control cinético.
Riccardo Pellarin1, Philipp Schuetz, Enrico Guarnera
1Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
Journal of the American Chemical Society
|October 7, 2010
Resumen
Los agregados amiloides exhiben diversas estructuras. Este estudio revela que las formas menos estables de las fibrillas a menudo se forman primero, lo que indica que la velocidad de formación, no solo la estabilidad, dicta el polimorfismo amiloide.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- La biofísica es la biofísica.
- Biología computacional Biología computacional.
Sus antecedentes:
- El autoensamblaje de proteínas en fibrillas amiloides está implicado en varias enfermedades.
- La formación amiloide exhibe una diversidad morfológica significativa (polimorfismo).
- Los factores que rigen el equilibrio de distintas morfologías de las fibrillas siguen sin estar claros.
Objetivo del estudio:
- Para investigar las vías de nucleación de distintas morfologías de las fibrillas amiloides.
- Para determinar la influencia de las condiciones externas en el polimorfismo amiloide.
- Para dilucidar el control cinético versus termodinámico de la formación de fibrillas.
Principales métodos:
- Utilizó simulaciones por computadora de un modelo simplificado de polipéptido amiloide.
- Se analizaron los perfiles de energía libre del proceso de agregación de proteínas.
- Investigó las barreras de nucleación para diferentes morfologías de fibrillas.
Principales resultados:
- Contrariamente a la intuición, las morfologías de fibrillas menos energéticamente favorables se nuclearon con más frecuencia.
- Este fenómeno se observó en modelos con baja propensión a la agregación.
- Se identificaron las barreras de nucleación como determinantes clave de las poblaciones de morfología de las fibrillas.
Conclusiones:
- El polimorfismo amiloide está principalmente bajo control cinético, no en equilibrio termodinámico.
- La barrera de nucleación influye significativamente en la abundancia relativa de las diferentes estructuras de las fibrillas.
- Comprender estos factores cinéticos es crucial para controlar el autoensamblaje amiloide.
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