TY - DATA T1 - Unzipping a Functional Microbial Amyloid PY - 2012/09/25 AU - David Alsteens AU - Caleen B. Ramsook AU - Peter N. Lipke AU - Yves F. Dufrêne UR - https://acs.figshare.com/articles/journal_contribution/Unzipping_a_Functional_Microbial_Amyloid/2483824 DO - 10.1021/nn3025699.s001 L4 - https://ndownloader.figshare.com/files/4126597 KW - cell adhesion proteins KW - force signatures KW - contact time KW - biofilm formation KW - pathogen Candida albicans KW - amyloid sequence yields KW - adhesion protein KW - strength KW - mechanism KW - cell adhesion KW - force microscopy KW - Als cell adhesion proteins KW - unzipping probability increases KW - extracellular fibres KW - Als proteins KW - amyloid interactions KW - Functional Microbial AmyloidBacterial N2 - Bacterial and fungal species produce some of the best-characterized functional amyloids, that is, extracellular fibres that play key roles in mediating adhesion and biofilm formation. Yet, the molecular details underlying their mechanical strength remain poorly understood. Here, we use single-molecule atomic force microscopy to measure the mechanical properties of amyloids formed by Als cell adhesion proteins from the pathogen Candida albicans. We show that stretching Als proteins through their amyloid sequence yields characteristic force signatures corresponding to the mechanical unzipping of β-sheet interactions formed between surface-arrayed Als proteins. The unzipping probability increases with contact time, reflecting the time necessary for optimal inter β-strand associations. These results demonstrate that amyloid interactions provide cohesive strength to a major adhesion protein from a microbial pathogen, thereby strengthening cell adhesion. We suggest that such functional amyloids may represent a generic mechanism for providing mechanical strength to cell adhesion proteins. In nanotechnology, these single-molecule manipulation experiments provide new opportunities to understand the molecular mechanisms driving the cohesion of functional amyloid-based nanostructures. ER -