title: Resolving the molecular structure of microtubules under physiological conditions with scanning force microscopy.
abstract: We have imaged microtubules, essential structural elements of the cytoskeleton in eukaryotic cells, in physiological conditions by scanning force microscopy. We have achieved molecular resolution without the use of cross-linking and chemical fixation methods. With tip forces below 0.3 nN, protofilaments with approximately 6 nm separation could be clearly distinguished. Lattice defects in the microtubule wall were directly visible, including point defects and protofilament separations. Higher tip forces destroyed the top half of the microtubules, revealing the inner surface of the substrate-attached protofilaments. Monomers could be resolved on these inner surfaces.
authors.affiliation: Section Physics of Complex Systems, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands. ischaap@nat.vu.nl
authors.forename: Iwan A T
authors.initials: IA
authors.lastname: Schaap
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: de Pablo
authors.forename: Christoph F
authors.initials: CF
authors.lastname: Schmidt
mesh_terms: D000818:Animals; D001921:Brain / Q000648:ultrastructure; D007089:Image Enhancement / Q000379:methods*; D018625:Microscopy, Atomic Force / Q000379:methods*; D008870:Microtubules / Q000648:ultrastructure*; D011487:Protein Conformation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*; D013314:Stress, Mechanical; D013552:Swine; D014404:Tubulin / Q000648:ultrastructure*
chemical_list: D014404:Tubulin