Bellesia, Giovanni; Shea, Joan-Emma
Effect of beta-sheet propensity on peptide aggregation
JOURNAL OF CHEMICAL PHYSICS, 130 Art. No. 145103, APR 14 2009

The effect of beta-sheet propensity on the structural features of peptide aggregates was investigated using an off-lattice coarse-grained peptide model. A phase diagram as a function of temperature and beta-sheet propensity reveals a diverse family of supramolecular assemblies. Highly rigid peptides (peptides with high beta-sheet propensity) are seen to assemble predominantly into fibrillar structures. Increasing the flexibility of the peptide (reducing beta-sheet propensity) leads to a variety of structures, including fibrils, beta-barrel structures, and amorphous aggregates. Nonfibrillar entities have been suggested as primary causative agents in amyloid diseases and our simulations indicate that mutations that decrease beta-sheet propensity will decrease fibril formation and favor the formation of such toxic oligomers. Parallels between beta-sheet aggregates and nematic liquid crystals are discussed.

DOI:10.1063/1.3108461

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