Nanomechanics of Amyloid Materials Studied by Atomic Force Microscopy

Amyloids are usually used to refer to a wide range of fibrous nanostructures formed from natural and synthetic proteins and peptides. The self-propagating protein aggregates are rich in ┚-sheets, which stack in hundreds to thousands units perpendicular to the fibrous axis, forming fibrils 5-15 nm in width and several micrometers in length (Dobson, 1999; Jaroniec et al., 2004; Luhrs et al., 2005; Sawaya et al., 2007; Wasmer et al., 2008). The structural trait gives amyloids the so called “cross-┚” diffraction pattern under X-ray crystallography as well as some tinctorial properties which they share in common, such as Congo red and thioflavin-T binding ability (Westermark et al., 1999) and the characteristic apple-green birefringence under polarized light when stained with Congo red.