We report an experimental study on the model protein Bovine Serum Albumin (BSA), with the aim of elucidatingthe mechanisms by which a fully folded globular protein undergoes different aggregation pathwaysleading to the formation of amyloid fibrils or amorphous aggregates. We observe thermally inducedformation of fibrillar structures at pH far from the protein isoelectric point. The increase of electrostaticrepulsion results in protein destabilization and in modifications of inter and intra-molecular interactionsleading to the growth of fibril-like aggregates stabilized by inter-molecular-b sheets. The aggregationkinetics is studied by means of fluorescence techniques, light scattering, Circular Dichroism (CD), infraredspectroscopy (FTIR) and Atomic Force Microscopy (AFM). Changes in protein secondary structures turnout to be the driving mechanism of the observed aggregation and they progress in parallel with thegrowth of Thioflavin T emission intensity and scattering signal. This concurrent behavior suggests amutual stabilization of elongated protofibril-like structures and of protein conformational and structuralchanges, which lead to a more rigid and ordered structures. Our results give new insights on BSA selfassemblyprocess in alkaline conditions clearly providing new pieces of evidences of the interplay of severaland interconnected mechanisms occurring on different time and length scales.
|Number of pages||12|
|Journal||Archives of Biochemistry and Biophysics|
|Publication status||Published - 2011|
All Science Journal Classification (ASJC) codes
- Molecular Biology