title: Noninvasive protein structural flexibility mapping by bimodal dynamic force microscopy.
abstract: Mapping of the protein structural flexibility with sub-2-nm spatial resolution in liquid is achieved by combining bimodal excitation and frequency modulation force microscopy. The excitation of two cantilever eigenmodes in dynamic force microscopy enables the separation between topography and flexibility mapping. We have measured variations of the elastic modulus in a single antibody pentamer from 8 to 18 MPa when the probe is moved from the end of the protein arm to the central protrusion. Bimodal dynamic force microscopy enables us to perform the measurements under very small repulsive loads (30-40 pN).
authors.affiliation: Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Martinez-Martin
authors.forename: E T
authors.initials: ET
authors.lastname: Herruzo
authors.forename: C
authors.initials: C
authors.lastname: Dietz
authors.forename: J
authors.initials: J
authors.lastname: Gomez-Herrero
authors.forename: R
authors.initials: R
authors.lastname: Garcia
mesh_terms: D055119:Elastic Modulus; D004548:Elasticity; D018625:Microscopy, Atomic Force / Q000295:instrumentation*; D011506:Proteins / Q000737:chemistry*
chemical_list: D011506:Proteins