A5002848884- Force Microscopy Techniques and Applications
- Mechanical and Optical Resonators
- Protein Structure and Dynamics
- Cellular Mechanics and Interactions
- Adhesion, Friction, and Surface Interactions
- Lipid Membrane Structure and Behavior
- Molecular Junctions and Nanostructures
- Bacterial Genetics and Biotechnology
- Advanced Electron Microscopy Techniques and Applications
- Monoclonal and Polyclonal Antibodies Research
- Nanopore and Nanochannel Transport Studies
- Cardiomyopathy and Myosin Studies
- RNA and protein synthesis mechanisms
- Bacterial biofilms and quorum sensing
- Particle Dynamics in Fluid Flows
- Escherichia coli research studies
- Caveolin-1 and cellular processes
- Receptor Mechanisms and Signaling
- Engineering and Material Science Research
- Wind and Air Flow Studies
- Fluid Dynamics and Turbulent Flows
- Nanocomposite Films for Food Packaging
- Silk-based biomaterials and applications
- Granular flow and fluidized beds
- Polymer Surface Interaction Studies
Ben-Gurion University of the Negev
2015-2024
The Technological College of Beer Sheva
2018-2020
Center for Nanoscale Science and Technology
2020
Columbia University
2010-2014
Tel Aviv University
2008-2012
The active site of the Haloalkane Dehydrogenase (HaloTag) enzyme can be covalently attached to a chloroalkane ligand providing mechanically strong tether, resistant large pulling forces. Here we demonstrate covalent tethering protein L and I27 polyproteins between an atomic force microscopy (AFM) cantilever glass surface using HaloTag anchoring at one end thiol chemistry other end. Covalent is unambiguously confirmed by observation full length polyprotein unfolding, combined with high...
The elastic restoring force of tissues must be able to operate over the very wide range loading rates experienced by living organisms. It is surprising that even fastest events involving animal muscle do not surpass a few hundred hertz. We propose this limit set in part dynamics tethered proteins extending and relaxing under changing load. Here we study using fast spectrometer with sub-millisecond time resolution, combined Brownian Molecular Dynamics simulations. show act tethering...
P. aeruginosa flagella are recorded across the entire biofilm life cycle as likely structural scaffolds.
Biomolecular interactions frequently occur in orientation-specific manner. For example, prior nuclear magnetic resonance spectroscopy experiments our lab have suggested the presence of a group strongly binding residues on particular face protein ubiquitin for with Capto MMC multimodal ligands ("Capto" ligands) (Srinivasan, K.; et al. Langmuir 2014, 30 (44), 13205–13216). We present clear confirmation those studies by performing single-molecule force (SMFS) measurements unbinding complemented...
Cell-surface proteins are central for the interaction of cells with their surroundings and also associated numerous diseases. These molecules exposed to mechanical forces, but exact relation between force functions pathologies cell-surface is unclear. An important protein CD4, primary receptor HIV-1. Here we show that activates conformational chemical changes on CD4 may be during viral attachment. We have used single-molecule spectroscopy analysis HIV-1 infectivity demonstrate extension...
Understanding atomic friction within a liquid environment is crucial for engineering mechanisms and characterizing surfaces. It has been suggested that the lattice resolution of force microscope in environments stems from dry contact state, with all molecules expelled area closest approach between tip substrate. Here, we revisit this assertion by performing in-depth microscopy experiments molecular dynamics simulations influence surrounding water on dynamic behavior nanotribological an amorphous SiO
Single-molecule force spectroscopy utilizes polyproteins, which are composed of tandem modular domains, to study their mechanical and structural properties. Under the application external load, polyproteins respond by unfolding refolding domains acquire most favored extensibility. However, unlike single-domain proteins, sequential each domain modifies free energy landscape (FEL) polyprotein nonlinearly. Here we use force-clamp (FC) measure collapse-refolding dynamics polyubiquitin poly(I91)....
Non‐integral membrane proteins frequently act as transduction hubs in vital signaling pathways initiated at the plasma (PM). Their biological activity depends on dynamic interactions with PM, which are governed by their lateral and cytoplasmic diffusion binding/unbinding kinetics. Accurate quantification of multiple kinetic parameters characterizing interaction dynamics has been challenging. Despite a fair number approximate fitting functions for analyzing fluorescence recovery after...
Abstract Ultrafast folding proteins have limited cooperativity and thus are excellent models to resolve, via single-molecule experiments, the fleeting molecular events that undergo during folding. Here we report atomic force microscopy experiments on gpW, a protein that, in bulk, folds few microseconds over marginal barrier (∼1 k B T ). Applying pulling forces of only 5 pN, maintain gpW quasi-equilibrium near its mechanical unfolding midpoint detect how it interconverts stochastically...
Chitosan hydrogels have widespread industrial applications due to their versatility and antimicrobial potential. However, applicability can be limited by poor mechanical properties or because fabrication requires the use of toxic compounds which leach into environment. Additionally, water solubility under neutral conditions restricts low pHs. Here, we synthesized a modified derivative [N-(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride (HTCC), is soluble at pH, used it compare effect...
Single molecule force spectroscopy is a useful technique for investigating mechanically induced protein unfolding and refolding under reduced forces by monitoring the end-to-end distance of protein. The data often interpreted via "two-state" model based on assumption that alone good reaction coordinate thermodynamic behavior then ascribed to free energy as function this one coordinate. In paper, we determined surface (PMF) GB1 from atomistic simulations in explicit solvent different applied...
We investigate the applicability of Jarzynski equality for reconstructing energy landscape from force measurements obtained in single molecular unbinding and friction experiments. demonstrate that single-well potentials, such as Lennard-Jones potential, could be accurately recovered using a reasonable number traces (∼100) velocities which are experimentally accessible, v≈5–100 nm s−1. The situation becomes more complex presence potential barriers profile. These include double-well periodic...
Friction force microscopy (FFM) in aqueous environments has recently proven to be a very effective method for lattice-resolution imaging of crystal surfaces. Here we demonstrate the use ethanol similar measurements on water-soluble materials. Lattice resolved frictional stick-slip traces cleaved NaCl(100) surface submerged are compared with previous obtained FFM results ultrahigh vacuum (UHV). We Prandtl-Tomlinson framework estimate amplitude corrugation potential and contact stiffness. The...
The application of direct force to a protein enables probe wide regions its energy surface through conformational transitions as unfolding, extending, recoiling, collapsing, and refolding. While unfolding under typically displayed two-state behavior, refolding force, from highly extended unfolded states, more complex behavior. first recording at quench step an initial rapid elastic recoil, followed by plateau phase some extension, concluding with collapse final state, which occurred. These...
Abstract Friction force microscopy (FFM) explores the interaction in a sliding contact on nanoscale, providing information frictional dynamics and lateral stiffness with lattice resolution. Recent FFM measurements NaCl crystal immersed liquid (ethanol) surroundings displayed an increase of effective stiffness, K eff , applied load, differently from similar performed under ultra-high vacuum (UHV) conditions, where showed negligible load dependency. Additionally, UHV conditions multiple slip...
We have numerically investigated the occurrence of long slips when a point mass representing tip solid surface is elastically driven on hexagonal lattice along an arbitrary direction. Tip pathways and slip length histograms are estimated for different values damping coefficient $\ensuremath{\gamma}$ defining duration phases. The results compared with map all possible ``slip channels'' as obtained analytically Prandtl-Tomlinson model in two dimensions. corresponding force drops could be...
Bacterial pathogens inject virulence factors into host cells during bacterial infections using type III secretion systems. In enteropathogenic Escherichia coli, this system contains an external filament, formed by a self-oligomerizing protein called E. coli secreted A (EspA). The EspA filament penetrates the thick viscous mucus layer to facilitate attachment of bacteria gut-epithelium. To do that, requires noteworthy mechanical endurance considering shear stresses found within intestinal...