Ile-phe dipeptide self-assembly: clues to amyloid formation.
Peptidic self-assembled nanostructures are said to have a wide range of applications in nanotechnology, yet the mechanistic details of hierarchical self-assembly are still poorly understood. The Phe-Phe recognition motif of the Alzheimer's Abeta peptide is the smallest peptide able to assemble into higher-order structures. Here, we show that the Ile-Phe dipeptide analog is also able to self-associate in aqueous solution as a transparent, thermoreversible gel formed by a network of fibrillar nanostructures that exhibit strong birefringence upon Congo red binding. Besides, a second dipeptide Val-Phe, differing only in a methyl group from the former, is unable to self-assemble. The detailed analysis of the differential polymeric behavior of these closely related molecules provides insight into the forces triggering the first steps in self-assembly processes such as amyloid formation.
de Groot
Natalia Sánchez
NS
Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain.
Parella
Teodor
T
Aviles
Francesc X
FX
Vendrell
Josep
J
Ventura
Salvador
S
D000682:Amyloid / Q000737:chemistry* / Q000648:ultrastructure; D004151:Dipeptides / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007532:Isoleucine / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D010649:Phenylalanine / Q000737:chemistry*
D000682:Amyloid; D004151:Dipeptides; D007532:Isoleucine; C026650:phenylalanylphenylalanine; D010649:Phenylalanine