Stepwise dynamics of epitaxially growing single amyloid fibrils.

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

SUBMITTER: Kellermayer MS 

PROVIDER: S-EPMC2224175 | biostudies-literature | 2008 Jan

REPOSITORIES: biostudies-literature