Structure and stability of amyloid fibrils formed from synthetic beta-peptides

Synthetic peptides capable of self-assembling into amyloid-like fibrillar structures are emerging as novel building blocks for biomaterials. They also serve as simple model systems to study the aggregation process involved in amyloid diseases. In this paper, we probe the structure and stability of fibrillar assemblies formed by two designed peptides P-11-I (CH3-CO-Q(2)RQ(5)EQ(2)-NH2) and P-11-II (CH3-CO-Q(2)RFQWQFEQ(2)-NH2). Our results suggest that the two peptides assemble by fundamentally different mechanisms to structures of different morphologies. Coulombic interactions between charged residues Arginine and Glutamate drive the self-assembly process for peptide P-11-I while the hydrophobic effect appears to be the main driving force in the self-assembly of peptide P-11-II.