Multifrequency Force Microscopy of Helical Protein Assembly on a Virus
Calò, Annalisa (CIC NanoGUNE)
Eleta López, Aitziber (CIC NanoGUNE)
Stoliar, Pablo (CIC NanoGUNE)
De Sancho, David (Basque Foundation for Science)
Santos, Sergio (Masdar Institute of Science and Technology)
Verdaguer Prats, Albert (Institut Català de Nanociència i Nanotecnologia)
Bittner, Alexander M. (Basque Foundation for Science)

Date:	2016
Abstract:	High-resolution microscopy techniques have been extensively used to investigate the structure of soft, biological matter at the nanoscale, from very thin membranes to small objects, like viruses. Electron microscopy techniques allow for obtaining extraordinary resolution by averaging signals from multiple identical structures. In contrast, atomic force microscopy (AFM) collects data from single entities. Here, it is possible to finely modulate the interaction with the samples, in order to be sensitive to their top surface, avoiding mechanical deformations. However, most biological surfaces are highly curved, such as fibers or tubes, and ultimate details of their surface are in the vicinity of steep height variations. This limits lateral resolution, even when sharp probes are used. We overcome this problem by using multifrequency force microscopy on a textbook example, the Tobacco Mosaic Virus (TMV). We achieved unprecedented resolution in local maps of amplitude and phase shift of the second excited mode, recorded together with sample topography. Our data, which combine multifrequency imaging and Fourier analysis, confirm the structure deduced from averaging techniques (XRD, cryoEM) for surface features of single virus particles, down to the helical pitch of the coat protein subunits, 2. 3 nm. Remarkably, multifrequency AFM images do not require any image postprocessing.
Grants:	Ministerio de Economía y Competitividad RYC-2012-01031
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Microscopy ; Tobacco Mosaic Virus ; Virion
Published in:	Scientific reports, Vol. 6 (February 2016) , art. 21899, ISSN 2045-2322

DOI: 10.1038/srep21899
PMID: 26915629

9 p, 1.0 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles