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Rapid Generation of Amyloid from Native Proteins In vitro
Published on: December 5, 2013
Amyloid fibrils formation of concanavalin A at basic pH
R Carrotta1, V Vetri, F Librizzi
1Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Palermo, Italy.
The Journal of Physical Chemistry. B
|March 12, 2011
Summary
Heat-induced protein aggregation, like that of concanavalin A (ConA), involves distinct steps. Intermolecular beta-sheet formation is a key rate-limiting step in creating amyloid-like fibrils and compact fractal aggregates.
Area of Science:
- Biochemistry
- Biophysics
- Structural Biology
Background:
- Protein misfolding and aggregation are implicated in numerous human diseases, often involving amyloid fibril formation.
- Understanding the mechanisms of protein aggregation is crucial for developing therapeutic strategies.
Purpose of the Study:
- To investigate the heat-induced aggregation mechanisms of concanavalin A (ConA) at basic pH.
- To elucidate the interplay between protein unfolding, beta-sheet formation, and aggregate structure.
Main Methods:
- Thioflavin T (ThT) fluorescence spectroscopy to monitor beta-sheet formation.
- Multiangle light scattering (MALS) to characterize aggregate size and structure.
- Atomic Force Microscopy (AFM) to visualize aggregate morphology.
Main Results:
- ThT fluorescence indicated the formation of intermolecular beta-sheet structures as a rate-limiting step.
- MALS data revealed a condensation process leading to compact fractal aggregates.
- AFM imaging showed initial thin fibrils that further assembled into netlike structures.
Conclusions:
- Concanavalin A aggregation at basic pH involves multiple intertwined steps, including beta-sheet formation and fractal aggregate assembly.
- The observed aggregation pathway provides insights into mechanisms relevant to amyloid-related pathologies.
- Protein concentration influences aggregation dynamics, with coagulation playing a role across studied concentrations.
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