Nanomechanical Properties of Amyloid Fibrils Formed in a Water Nanofilm on Mica Surface

The assessment of nanomechanical properties of a single amyloid fibril in a confined space provides important information for understanding the role of fibrils in a cell microenvironment. In this study, the structure and nanomechanical properties of different fibrils formed in water nanofilms on mica surface are carefully investigated by using the new atomic force microscopy imaging mode-peak force quantitative nanomechanics (PF-QNM). We find that two types of fibrils with different morphologies are formed in water nanofilm on mica. The compression elasticities of these two types of fibrils are 3.9\pm0.9 and 2.5\pm0.6 GPa, respectively. The remarkable difference is possibly due to the structural discrepancy in two types of fibrils.