Stepwise dynamics of epitaxially growing single amyloid fibrils

• DOI: 10.1073/pnas.0704305105
• Publication Date: 2007-12-28T01:33:54Z
• Authors: Miklós S. Z. Kell...; Árpád Karsai; Margit Benke; Katalin Soós; Botond Penke
• Keywords: Amyloid (mycology)

The assembly mechanisms of amyloid fibrils, tissue deposits in a variety degenerative diseases, is poorly understood. With simply modified application the atomic force microscope, we monitored growth, on mica surface, individual fibrils beta25-35 peptide with near-subunit spatial and subsecond temporal resolution. Fibril was polarized discontinuous. Bursts rapid (up to 300-nm(-1)) growth phases that extended fibril by approximately 7 nm or its integer multiples were interrupted pauses. Stepwise dynamics also observed for beta1-42 growing graphite, suggesting discontinuous may be general feature epitaxial growth. Amyloid thus involve fluctuation between fast-growing blocked state which kinetically trapped because intrinsic structural features. used scanning-force kymography method adapted analyze wide range linear biopolymers.