Dynamic Modulation of Fimbrial Extension and FimH-Mannose Binding Force on Live Bacteria Under pH Changes: A Molecular Atomic Force Microscopy Analysis

Fast automated processing of AFM PeakForce curves to evaluate spatially resolved Young modulus and stiffness of turgescent cells

“…It is not straightforward to precisely identify the reasons for the above features given the crude assumptions of isotropic and elastic cell material underlying the obvious (and well recognized) reduced applicability of both the Hertz and Sneddon models for biological samples. 57 In particular, eqn (1) and 7render impossible the differentiated evaluations of the respective elastic and entropic contributions of the outer cell membrane and of the surrounding lipopolysaccharidic cushion (if relevant, see discussion in Section 3.5) or any other surface biomolecules 65,66 to the here-obtained effective Young modulus E. Alternatives do exist, as proposed e.g. by Gaboriaud et al, 14 Guz et al, 67 Mercade-Prieto et al 68 for bacteria, brush-like decorated human cells, and yeasts, respectively.…”

The Role of Glycans in Bacterial Adhesion to Mucosal Surfaces: How Can Single-Molecule Techniques Advance Our Understanding?

“…Stress induced separation of FimH protein domains lead to increased affinity of the lectin domain. The strength of the FimH-mannose interaction was later investigated using AFM in a study where the authors concluded that the interaction strength was in the interval 50 to 75 pN and quasi-independent of the applied pulling force [ 123 ]. However, in this study, the loading rate was not determined and this lack of information hinders a proper analysis of the potential catch bond effect.…”

Electrophoresis of composite soft particles with differentiated core and shell permeabilities to ions and fluid flow

“…Electrophoresis is a well-established technique for addressing the electrostatic properties of abiotic and biotic colloidal particles in aqueous solution [1][2]. Pending proper conversion of the measured electrophoretic mobility into relevant particle electrostatic descriptors, electrophoresis provides a way to capture how electrostatics contributes to (bio)particles stability against aggregation [2][3], how it impacts (or not) nanoparticle-cell, cell-cell or nanoparticle-functionalized surface interactions [4][5][6], the attachment of bacteria to surfaces [7][8][9], the binding of metal ions to (nano)particles [10][11][12], the transport of particles in porous media [13][14][15], the accumulation of metal ions in microorganisms [16] or even the response of bioluminescent metal-sensing bacterial reporters [17][18]. Quantitative interpretation of electrophoretic mobility data and subsequent evaluation of the defining particle electrostatic features differ according to the type of particles examined, in particular the magnitude of their permeability to electrolyte ions and to the (electroosmotic) flow developed under electrokinetic conditions.…”