Berlin 2005 – scientific programme
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AKB: Biologische Physik
AKB 75: Nonlinear Phenomena and Pattern Formation
AKB 75.5: Talk
Wednesday, March 9, 2005, 11:30–11:45, TU H2013
Mechanical Properties of self-assembling biomolecular tubes — •Iwan A.T. Schaap1, Pedro J. de Pablo1, Catherine Tardin1, Andrew Turberfield2, Richard Berry2, Cees G. de Kruif3, Joanke Graveland3, Bernd Hoffmann4, Frederick C. MacKintosh1, and Christoph F. Schmidt1 — 1Dept. Physics, Vrije Universiteit, Amsterdam, NL — 2Dept. Physics, Oxford University, Oxford, UK — 3NIZO Food Research, Ede, NL — 4Forschungsztr. Julich, Julich, D
Biomacromolecules often have the capability to self-assemble into either functional and well regulated or pathogenic unregulated structures. Examples for the former are cytoskeletal filaments such as microtubules, 25 nm hollow tubes made of tubulin protein. The latter occurs in many neurodegenerative diseases (amyloid formation). Molecular self-assembly can also be put to technical use, for example by engineering self-assembling DNA building blocks. We have employed an atomic force microscope (AFM) operated at well-controlled low forces to image under physiological conditions various tube-like structures at nm resolution, including microtubules with and without accessory proteins, protein amyloid tubes and DNA tubes. To measure mechanical properties, we have indented individual tubes locally with the AFM tip. The deformation is elastic for the few nm of indentation. By indenting with higher forces, we can exceeded elastic limits and produce local defects.