AFM imaging of TMV

PELLEQUER Jean-Luc — 2018-08-23T12:54:42Z

Can we estimate the impact of AFM perturbation to an imaged single molecule?

Schematic cross-section of a single TMV particle. X-ray diffraction shows that TMV has a diameter of 19 nm. By changing the sample substrate (mica on the left and self-assembled monolayers, SAM, on the right) and by changing imaging parameters (Liq for liquid, PFT for PeakForce Tapping, TAP for Tapping), we can clearly note changes in the TMV height (diameter). It is shown that the choice of the substrate brings the largest changes in TMV height. This study also shown that TMV imaging in air is perfectly possible at the condition of using a "soft" substrate and a soft imaging mode. AFM measurements were made over several years with Christian Godon, Jean-Marie Teulon, and Michael Odorico. TMV purification was performed by Christian Basset. SAM surfaces were produced by Matthieu Meillan under the supervision of Luc Vellutini. The analytical image processing and height computation was developped by Wendy Chen.

Godon C, Teulon J-M, Odorico M, Basset C, Meillan M, Vellutini L, Chen S-wW and Pellequer J-L (2017) Conditions to minimize soft single biomolecule deformation when imaging with atomic force microscopy. J. Struct. Biol. 197: 322-329.

TMV and SAXS radiation damages

2018-08-23T11:35:39Z

SAXS radiation damages on virus particles

The figure shows TMV particles deposited on graphite (top line) or on NiCl2 pretreated mica (bottom line). The left column shows native TMV, the middle column shows TMV after 10 sec (standard exposition time) X-ray exposure, and the right column shows TMV after 30 min X-ray exposure. Although, a degradation of TMV particles is clearly seen at 30 min exposure, a detectable degradation of TMV particles is already seen after only 10 sec X-ray exposure. The AFM images were made by Alexander Andriatis under the supervision of Luca Costa and with the help of Martha Brennich for the SAXS data acquisition.

The radiation damages on the globular enzyme β-amylase have also been studied.

Costa L, Andriatis A, Brennich M, Teulon J-M, Chen SWW, Pellequer J-L and Round A (2016) Combined small angle X-ray solution scattering with atomic force microscopy for characterizing radiation damage on biological macromolecules. BMC Struct. Biol. 16: 18.

IBS - Institut de Biologie Structurale - Grenoble / France

AFM imaging of TMV

TMV and SAXS radiation damages