Diociaiuti M, Bordi F, Motta A, Carosi A, Ercolini E, Arancia G, Cametti C, Coluzza C. Gramicidin A aggregation in phospholipid Langmuir-Blodget monolayers: an atomic force microscopy study. In: 12. European Congress on Electron Microscopy. Proceedings ; July 9-14, 2000; Brno. 2000. p.B535-B536 ...
TY - JOUR. T1 - Tapping mode atomic force microscopy of scleroglucan networks. AU - Vuppu, A. K.. AU - Garcia, Antonio. AU - Vernia, C.. PY - 1997/1/1. Y1 - 1997/1/1. N2 - Tapping mode Atomic Force Microscopy (TniAFM) has been used to study the fungal polysaccharide scleroglucan deposited from aqueous solution and dimethyl sulfoxide (DMSO) onto a mica surface. The solutions from which the microscope samples were produced were prepared by first dissolving the solid scleroglucan in 0.1M NaOH, then neutralizing the solution with HCl, followed by dilution to the required concentration in either water or DMSO. It was found that from the aqueous solution described above, scleroglucan forms networks. Based on a comparison of the denatured-renatured and aqueous solution samples, nehvork formation is due to the imperfect registration bet\veen the chains fanning the triple helices. The relatively large stiffness of the scleroglucan triple helix is also assumed to contribute to the formation of the ...
Park Systems, a leader in Atomic Force Microscopy (AFM) since 1997 announces their first AFM image contest winner, Namuna Panday, a Graduate Student at Florida International University. Her winning submission is an AFM image taken using Park XE Bio of a HeLa Cell used in her research studying drug delivery methods for cancer research.
Atomic force microscopy (AFM) for single-cell force spectroscopy (SCFS) and Poisson statistic were used to analyze the detachment work recorded during the removal of gold-covered microspheres from cardiac fibroblasts. The effect of Cytochalasin D, a disruptor of the actin cytoskeleton, on cell adhesion was also tested. The adhesion workwas assessed using a Poisson analysis also derived fromsingle-cell force spectroscopy retracting curves. The use of Poisson analysis to get adhesionwork fromAFM curves is quite a novel method, and in this case, proved to be effective to study the short-range and long-range contributions to the adhesion work. This method avoids the difficult identification of minor peaks in the AFMretracting curves by creating what can be considered an average adhesionwork. Even though the effect of actin depolymerisation iswell documented, its use revealed that control cardiac fibroblasts (CT) exhibit a work of adhesion at least 5 times higher than that of the Cytochalasin treated ...
In this thesis properties and influence of modification techniques of porous silicon were studied by Atomic Force Microscope (AFM). This device permits to visualize the surface topography and to study properties of the samples on atomic scale, which was necessary for recent investigation. Samples of porous silicon were obtained by electrochemical etching. Nickel particles were deposited by two methods: electrochemical deposition and extracting from NiCl2 ethanol solution. Sample growth was conducted in Saint-Petersburg State Electrotechnical University, LETI ...
Direct observations of fine structure of DNA bundles were presented in this paper. These DNA bundles existed originally in lambda -DNA solution with a high concentration of 480ng/mul. When this solution was diluted. DNA bundles finally split into individual DNA molecules. DNA bundles were stretched on mica treated with 3-animopropyl triethoxysilane (APS) and observed by an atomic force microscope (AFM), A method was developed to avoid the possible artifacts during the drying process in,,ample preparation. It was found that in a bundle composed of two individual DNA molecules, these two molecules wound around each other in a helical path ...
From consumer productions to energy production, algae is used in many industrial processes. Understanding the mechanical behavior of algae is important to optimize these processes. To obtain a better understanding of algae cell response, we mechanically characterized single, dried Scenedesmus dimorphus cells. To accomplish this, we used atomic force microscopy (AFM) to image S. dimorphus cells, which enabled us to map the AFM measurements to a location on the individual cells. We were then able to perform force measurements on the AFM to determine the Youngs modulus of S. dimorphus. These findings enable a more detailed understanding of the mechanical properties of a single S. dimorphus cell, which may be useful in many applications.. Copyright © 2013 by ASME ...
Advanced atomic force microscopy techniques IV is a Thematic Issue edited by Thilo Glatzel in the Open Access Beilstein Journal of Nanotechnology.
TY - JOUR. T1 - Imaging and force-distance analysis of human fibroblasts in vitro by atomic force microscopy. AU - Bushell, Gillian R.. AU - Cahill, Colm. AU - Clarke, Frank M.. AU - Gibson, Christopher T.. AU - Myhra, Sverre. AU - Watson, Gregory S.. PY - 1999/7/1. Y1 - 1999/7/1. N2 - The structure of human fibroblasts have been characterised in vitro by atomic force microscopy (AFM) operated in the imaging or in the force versus distance (F-d) modes. The choice of cell substrate is important to ensure good adhesion. Of greater significance in the context of AFM analysis, is the observation that the substrate affects the imaging conditions for in vitro analysis of live cells. For instance, very rarely will glass coverslips lead to acceptable outcomes (i.e., resolved cytoskeletal structure). Activated tissue culture dishes, on the other hand, promote conditions that routinely result in good quality images. Those conditions are then unaffected by adoption of relatively high force loadings (more ...
Kenta Iwashima, Kenji Watanabe, and Jiro Kumaki. Department of Organic Materials Science, Yamagata University, Japan. Polymer monolayers spread on a water surface transform from an isolated chain to amorphous, then to a crystalline state upon compression, which can be transferred at each stage onto a substrate for observation by atomic force microcopy (AFM) [1]. Previously, we successfully observed a folded chain crystal (FCC) of an isotactic poly(methyl methacrylate) (it-PMMA) [2], its melting behavior in situ at high temperature [3], and crystallization of single isolated chains [4] at a molecular level by AFM.. In contrast to the it-PMMA, polylactide (PLA) crystallizes into an extended chain crystal (ECC) on a water surface [5]. Since the width of the crystal corresponds to the molecular weight (Mw), the chain packing in the crystal can be specifically identified. We studied the crystallization of a mixture of high and low Mw PLAs and found that the high Mw PLA first crystallized, followed by ...
Titin (also known as connectin) is the main determinant of physiological levels of passive muscle force. experiments using Ig-domain unfolding parameters obtained in earlier single-molecule atomic force microscopy experiments recover the phenomenology of stress AG-490 relaxation and predict large-scale unfolding in titin during an extended period (>20 min) of relaxation. By contrast, immunolabeling experiments failed to demonstrate large-scale unfolding. Thus, under physiological conditions in relaxed human soleus fibers, Ig domains are more stable than predicted by atomic force microscopy experiments. Ig-domain unfolding did not become more pronounced after gelsolin treatment, suggesting that the thin filament is unlikely to significantly contribute to AG-490 the mechanical stability of the domains. We conclude that in human soleus fibers, Ig unfolding cannot solely explain stress relaxation. INTRODUCTION When nonactivated striated muscle is stretched, passive force ensues. Passive force is ...
In this thesis methods for investigation of orientation and conformation of individual macromolecules on surfaces are presented as well as novel methods for functionalization of silicon chips with the possibility to get an ordered immobilization of antibodies. Two novel methods are presented which makes it possible to investigate the orientation of individual macromolecules on different kinds of surfaces with AFM. One is based on threshold patterning where, depending on substrate, side- and end-on adsorbed immunoglobulin molecules could be detected. The other method is using the principle of site-specific ligands where the orientation of proteins adsorbed to various surfaces was evaluated. By measuring the increase in protein volume of the formed protein-ligand complexes with AFM, the amount of protein having an orientation that allows binding can be estimated. The influence of surface chemistry on protein structure was examined using human serum fibronectin adsorbed to hydrophilic and ...
Публикации за 2009 год. Strekal, N.; Kulakovich, O.; Askirka, V.; Sveklo, I.; Maskevich, S. Features of the Secondary Emission Enhancement Near Plasmonic Gold Film, - Plasmonics, 2009, Vol. 4, pp. 1-7.. A.V. Belko, A.V. Nikitin, N.D. Strekal, A.E. German. Fractal Structure of Gold Clusters Formed under Vacuum Deposition on Dielectric Substrates // X-ray, Synchrotron and Neutron Techniques, 2009, Vol. 3, No. 3, pp. 338-342.. A Hyper-Raman Spectroscopy, Spectrophotometry and Atomic Force Microscopy Study of Photochromism of Spirocyclic Compounds on Nanostructured Metal Films / G.T. Vasilyuk, S.A. Maskevich, A.E. German, I.F. Sveklo, B.S. Lukyanov, L.A. Ageev. // High Energy Chemistry, 2009,Vol.43, No.7, pp.623-627.. ...
This paper demonstrates an acoustic sensor that can resolve atomic force microscopy (AFM) tip blunting with a frequency sensitivity of 0.007%. The AFM tip is fabricated on a thin film piezoelectric aluminum nitride (AlN) membrane that is excited as a film bulk acoustic resonator (FBAR). We demonstrate that cutting 0.98 μm off of the tip apex results in a resonance frequency change of 0.4MHz at 6.387GHz. This work demonstrates the potential for in-situ monitoring of AFM tip wear.
TY - JOUR. T1 - Structural and Nanomechanical Properties of Paperboard Coatings Studied by Peak Force Tapping Atomic Force Microscopy. AU - Sababi, Majid. AU - Kettle, John. AU - Rautkoski, Hille. AU - Claesson, Per M.. AU - Thormann, Esben. PY - 2012. Y1 - 2012. N2 - Paper coating formulations containing starch, latex, and clay were applied to paperboard and have been investigated by scanning electron microscopy and Peak Force tapping atomic force microscopy. A special focus has been on the measurement of the variation of the surface topography and surface material properties with a nanometer scaled spatial resolution. The effects of coating composition and drying conditions were investigated. It is concluded that the air-coating interface of the coating is dominated by close-packed latex particles embedded in a starch matrix and that the spatial distribution of the different components in the coating can be identified due to their variation in material properties. Drying the coating at an ...
Looking for atomic force microscope? Find out information about atomic force microscope. device that uses a spring-mounted probe to image individual atoms on the surface of a material, first developed by Gerd Binnig Binnig, Gerd , 1947-, German... Explanation of atomic force microscope
To examine this behavior, the group used atomic force microscopy on clusters of one such FG domain, called cNup153, tethered at one end to gold nanodots. The forces exerted by the cluster just nanometers above the dot were reminiscent of the behavior of a physical phenomenon known as polymer brushes. Specifically, random flexible movements of polymers (or unfolded FG domains) create a large exclusion volume. Interactions between hydrophobic FG repeats were not seen, suggesting that FG Nups do not form a meshwork. ...
Author: Vollhardt, D. et al.; Genre: Journal Article; Published in Print: 1996; Title: Nucleation and growth of three-dimensional structures in supersaturated arachidic acid monolayers: An atomic force microscopy study
Author: Vollhardt, D. et al.; Genre: Journal Article; Published in Print: 1996; Title: Nucleation and growth of three-dimensional structures in supersaturated arachidic acid monolayers: An atomic force microscopy study
TY - JOUR. T1 - Cross-species mechanical fingerprinting of cardiac myosin binding protein-C. AU - Karsai, Árpád. AU - Kellermayer, Miklós S Z. AU - Harris, Samantha P.. PY - 2013/6/4. Y1 - 2013/6/4. N2 - Cardiac myosin binding protein-C (cMyBP-C) is a member of the immunoglobulin (Ig) superfamily of proteins and consists of 8 Ig- and 3 fibronectin III (FNIII)-like domains along with a unique regulatory sequence referred to as the MyBP-C motif or M-domain. We previously used atomic force microscopy to investigate the mechanical properties of murine cMyBP-C expressed using a baculovirus/insect cell expression system. Here, we investigate whether the mechanical properties of cMyBP-C are conserved across species by using atomic force microscopy to manipulate recombinant human cMyBP-C and native cMyBP-C purified from bovine heart. Force versus extension data obtained in velocity-clamp experiments showed that the mechanical response of the human recombinant protein was remarkably similar to that of ...
Posch, S. and Aponte-Santamaría, C. and Schwarzl, R. and Karner, A. and Radtke, M. and Gräter, F. and Obser, T. and König, G. and Brehm, M. A. and Gruber, H. J. and Netz, R. R. and Baldauf, C. and Schneppenheim, R. and Tampé, R. and Hinterdorfer, P. - 2016 ...
Tenascin-X is an extracellular matrix protein and binds a variety of molecules in extracellular matrix and on cell membrane. Tenascin-X plays important roles in regulating the structure and mechanical properties of connective tissues. Using single-molecule atomic force microscopy, we have investigated the mechanical properties of bovine tenascin-X in detail. Our results indicated that tenascin-X is an elastic protein and the fibronectin type III (FnIII) domains can unfold under a stretching force and refold to regain their mechanical stability upon the removal of the stretching force. All the 30 FnIII domains of tenascin-X show similar mechanical stability, mechanical unfolding kinetics, and contour length increment upon domain unfolding, despite their large sequence diversity. In contrast to the homogeneity in their mechanical unfolding behaviors, FnIII domains fold at different rates. Using the 10th FnIII domain of tenascin-X (TNXfn10) as a model system, we constructed a polyprotein chimera ...
The nanomechanical properties of living cells, such as their surface elastic response and adhesion, have important roles in cellular processes such as morphogenesis, mechano-transduction, focal adhesion, motility, metastasis and drug delivery. Techniques based on quasi-static atomic force microscopy
TY - CHAP. T1 - Characterization of DNA bound cyclic GMP-AMP synthase using atomic force microscopy imaging. AU - Lushnikov, Alexander. AU - Hooy, Richard. AU - Sohn, Jungsan. AU - Krasnoslobodtsev, Alexey. PY - 2019/1/1. Y1 - 2019/1/1. N2 - The protocol described herein allows for acquiring topography images of DNA-protein complexes using Atomic Force Microscopy imaging. Since the very beginning of this method, AFM has been an indispensable tool for characterization of biomolecular complexes with exceptional capability of observing single complexes. This method can visualize structural characteristics of DNA-protein assemblies and evaluate differences between individual complexes. Although this protocol is generally applicable to a large number of various proteins complexed with DNA, we use cyclic G/AMP synthase (cGAS) enzyme as a case study for the protocol description.. AB - The protocol described herein allows for acquiring topography images of DNA-protein complexes using Atomic Force ...
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We use a single molecule atomic force spectroscopy combined with the steered molecular dynamics simulation to determine a mechanical behavior of neural cell adhesion protein contactin during its unfolding. Force curves typical for modular proteins were observed, showing at most four unfolding peaks. The analysis of force spectra performed within worm-like chain model of polymer elasticity showed the presence of three unfolding lengths. Small plateaus, most likely resulting from forced transitions within domains were observed for the first time. Steered molecular dynamics simulations help to determine atomistic picture of domain unfolding ...
TY - JOUR. T1 - Atomic force microscopy observation and characterization of single virions and virus-like particles by nano-indentation. AU - Marchetti, M.. AU - Wuite, G.J.L.. AU - Roos, W.H.. PY - 2016. Y1 - 2016. N2 - Structure and function of viruses are intimately related, and one of the goals in virology is to elucidate the mechanisms behind this relation. A variety of research endeavours is focused on studying these mechanisms and a relatively new technique in this field is Atomic Force Microscopy (AFM). Using AFM virions and virus-like particles can be imaged and manipulated at the single particle level. Here we review recent AFM nano-indentations studies unveiling for instance the mechanics of capsid-genome interactions, morphological changes that drive viral maturation, capsid stabilizing factors and viral uncoating. We show that in an increasing amount of literature a clear link between mechanics and infectivity is observed, which not only provides us with new fundamental insights ...
Park Systems provides the widest range of atomic force microscopes and Bio SICM featuring one-click AFM imaging and True Non-Contact atomic force microscopy.
Knowledge of the surface properties of microbial cells is a key to gain a detailed understanding of their functions in the natural environment and to efficiently exploit them in biotechnological processes. In this paper, we present force-distance curves recorded, by atomic force microscopy (AFM) in aqueous solutions, on various microbial samples: reconstituted S-layers, whole fungal spores and several bacterial strains. The approach and retraction curves exhibited important differences--depending on the type of microorganism, on the physiological state (dormancy versus germination) and on the environmental conditions (ionic strength)--which were shown to reflect differences in long-range surface forces, adhesion forces and mechanical properties. These data illustrate the great potential of AFM force measurements to elucidate the physical properties of microbial cells and to understand, at the molecular level, biointerfacial phenomena such as cell adhesion and cell aggregation. ...
TY - JOUR. T1 - Direct atomic force microscopy observation of DNA tile crystal growth at the single-molecule level. AU - Evans, Constantine G.. AU - Hariadi, Rizal F.. AU - Winfree, Erik. PY - 2012/6/27. Y1 - 2012/6/27. N2 - While the theoretical implications of models of DNA tile self-assembly have been extensively researched and such models have been used to design DNA tile systems for use in experiments, there has been little research testing the fundamental assumptions of those models. In this paper, we use direct observation of individual tile attachments and detachments of two DNA tile systems on a mica surface imaged with an atomic force microscope (AFM) to compile statistics of tile attachments and detachments. We show that these statistics fit the widely used kinetic Tile Assembly Model and demonstrate AFM movies as a viable technique for directly investigating DNA tile systems during growth rather than after assembly.. AB - While the theoretical implications of models of DNA tile ...
When a material breaks into more than one piece, the cleavage occurs through some combination of brittle and ductile failure. During brittle failure, bonds are ruptured and there is little overall stretching of the material. During ductile failure, atoms or molecules slide past each other and the material deforms plastically before finally breaking. Glass is typically thought to break only through brittle failure, although it is known that plastic deformation will occur when glass is indented or scratched. Recent observations also suggested that cavities formed during glass fracture, implying that brittle materials also fracture via plastic flow instead of via bond rupture.. Guin and Wiederhorn used atomic force microscopy to study the topology of slowly fractured silica and soda-lime-silicate glasses. Mapping the high-contrast points from one of the fracture surfaces revealed that they mirror those on the opposing surface. Line scans of the two surfaces revealed that the vertical error between ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
TY - JOUR. T1 - Probing intra-molecular mechanics of single circularly permuted green fluorescent protein with atomic force microscopy. AU - Wang, Tong. AU - Nakajima, Ken. AU - Miyawaki, Atsushi. AU - Hara, Masahiko. PY - 2005/11/1. Y1 - 2005/11/1. N2 - We investigated the mechanical unfolding of single circularly permuted green fluorescent protein (cpGFP) with atomic force microscopy (AFM). The molecule was stretched from its N- and C-termini by an external force causing an elongation of the polypeptide chain up to its full length. The features of the force-extension (F-E) curves were found to depend on the stretching speed. At fast speeds, we detected one peak in the F-E curves before final rupture of the extended molecule, which we interpreted as the unfolding of two terminal halves within cpGFP. We observed several more force peaks in a sawtooth pattern at much slower speeds, and explained the appearance of such force peaks as cooperative unfolding of the hidden sub-structures inside each ...
Several techniques have been used in studying the structure of DNA, one of which is electron microscopy (EM). However, several issues on sample preservation have arisen with this technique due to its tedious sample preparation requirements. As a result, the atomic force microscope (AFM) was developed to overcome such shortcomings.
TY - JOUR. T1 - A method to provide rapid in situ determination of tip radius in dynamic atomic force microscopy. AU - Santos, Sergio. AU - Guang, Li. AU - Souier, Tewfik. AU - Gadelrab, Karim. AU - Chiesa, Matteo. AU - Thomson, Neil H.. PY - 2012/4. Y1 - 2012/4. N2 - We provide a method to characterize the tip radius of an atomic force microscopy in situ by monitoring the dynamics of the cantilever in ambient conditions. The key concept is that the value of free amplitude for which transitions from the attractive to repulsive force regimes are observed, strongly depends on the curvature of the tip. In practice, the smaller the value of free amplitude required to observe a transition, the sharper the tip. This general behavior is remarkably independent of the properties of the sample and cantilever characteristics and shows the strong dependence of the transitions on the tip radius. The main advantage of this method is rapid in situ characterization. Rapid in situ characterization enables one to ...
Recent developments in dynamic Atomic Force Microscopy where several eigenmodes are simultaneously excited in liquid media are proving to be an excellent tool in biological studies. Despite its relevance, the search for a reliable, efficient, and strong cantilever excitation method is still in progress. Herein, we present a theoretical modeling and experimental results of different actuation methods compatible with the operation of Atomic Force Microscopy in liquid environments: ideal acoustic, homogeneously distributed force, distributed applied torque (MAC Mode™), photothermal and magnetostrictive excitation. From the analysis of the results, it can be concluded that magnetostriction is the strongest and most efficient technique for higher eigenmode excitation when using soft cantilevers in liquid media. ...
2014 AIP Publishing LLC. Recent developments in dynamic Atomic Force Microscopy where several eigenmodes are simultaneously excited in liquid media are proving to be an excellent tool in biological studies. Despite its relevance, the search for a reliable, efficient, and strong cantilever excitation method is still in progress. Herein, we present a theoretical modeling and experimental results of different actuation methods compatible with the operation of Atomic Force Microscopy in liquid environments: ideal acoustic, homogeneously distributed force, distributed applied torque (MAC Mode™), photothermal and magnetostrictive excitation. From the analysis of the results, it can be concluded that magnetostriction is the strongest and most efficient technique for higher eigenmode excitation when using soft cantilevers in liquid media ...
With its ability to explore the surface of the sample by means of a local scanning probe and its use of dedicated software allows to be visualize results, atomic force microscopy (AFM) has revolutionized the study of the smallest aspects of life. Atomic Force Microscopy in Biomedical Research:
The environmental circumstances related to altering the hydration state of lively pharmaceutical components (API) are essential to understanding their stability, bioperformance, and manufacturability. Identifying the dehydration occasion utilizing , 1μg of materials is an more and more vital problem. Atomic Force Microscopy indentation mapping is carried out at managed temperatures between 25-100°C, for nanoscale volumes … Read more Atomic Force Microscopy to Identify Dehydration Temperatures for Small Volumes of Active Pharmaceutical Ingredients.. ...
PSIs Experts Perform Atomic Force Microscopy Or AFM Analysis To Measure Differences In Modulus And Height Of Materials In The Nanoscale Size.
Evaluation of peptide-material interaction by force mapping method with an atomic force microscopeEvaluation of peptide-material interaction by force mapping method with an atomic force microscope ...
The displacement adsorption process of 4-mercaptopyridine (4-MP) on trisodium citrate preadsorbed gold surface in aqueous solution was studied using atomic force microscopy (AFM). The measurement was done by monitoring the interaction force between a gold-coated AFM tip and a gold substrate, both presaturated by trisodium citrate. The addition of 4-MP was found to result in a remarkable change of tip−substrate adhesion force, which showed a gradual increase and finally reached a maximum. Using the chemical force titration technique, we estimated the surface pK1/2 of thus-formed 4-MP displacement film and compared with pure 4-MP self-assembled monolayer (SAM) formed on gold in ethanol solution. Our results indicate that the 4-MP molecules are more strongly adsorbed on gold than citrate anions, mostly via Au−S bonding, forming a less dense and mixed displacement film. The displacement adsorption kinetics seems very fast and it takes only ca. 2 min to establish more than 50% surface coverage of ...
TY - JOUR. T1 - The micro-mechanics of single molecules studied with atomic force microscopy. AU - Fisher, Thomas E.. AU - Marszalek, Piotr E.. AU - Oberhauser, Andres. AU - Carrion-Vazquez, Mariano. AU - Fernandez, Julio M.. PY - 1999/10/1. Y1 - 1999/10/1. N2 - The atomic force microscope (AFM) in its force-measuring mode is capable of effecting displacements on an angstrom scale (10 Å = 1 nm) and measuring forces of a few piconewtons. Recent experiments have applied AFM techniques to study the mechanical properties of single biological polymers. These properties contribute to the function of many proteins exposed to mechanical strain, including components of the extracellular matrix (ECM). The force-bearing proteins of the ECM typically contain multiple tandem repeats of independently folded domains, a common feature of proteins with structural and mechanical roles. Polysaccharide moieties of adhesion glycoproteins such as the selectins are also subject to strain. Force-induced extension of ...
Understanding how cell adhesion proteins form adhesion domains is a key challenge in cell biology. Here, we use single-molecule atomic force microscopy (AFM) to demonstrate the force-induced formation and propagation of adhesion nanodomains in living fungal cells, focusing on the covalently anchored cell-wall protein Als5p from Candida albicans. We show that pulling on single adhesins with AFM tips terminated with specific antibodies triggers the formation of adhesion domains of 100-500 nm and that the force-induced nanodomains propagate over the entire cell surface. Control experiments (with cells lacking Als5p, single-site mutation in the protein, bare tips, and tips modified with irrelevant antibodies) demonstrate that Als5p nanodomains result from protein redistribution triggered by force-induced conformational changes in the initially probed proteins, rather than from nonspecific cell-wall perturbations. Als5p remodeling is independent of cellular metabolic activity because heat-killed ...
The self-assembly of peptides and proteins into amyloid fibrils of nanometric thickness and up to several micrometres in length, a phenomenon widely observed in biological systems, has recently aroused a growing interest in nanotechnology and nanomedicine. Here we have applied atomic force microscopy and single molecule force spectroscopy to study the amyloidogenesis of a peptide derived from human amylin and of its reverse sequence. The spontaneous formation of protofibrils and their orientation along well-defined directions on graphite and DMSO-coated graphite substrates make the studied peptides interesting candidates for nanotechnological applications. The measured binding forces between peptides correlate with the number of hydrogen bonds between individual peptides inside the fibril structure according to molecular dynamics simulations ...
The self-assembly of peptides and proteins into amyloid fibrils of nanometric thickness and up to several micrometres in length, a phenomenon widely observed in biological systems, has recently aroused a growing interest in nanotechnology and nanomedicine. Here we have applied atomic force microscopy and single molecule force spectroscopy to study the amyloidogenesis of a peptide derived from human amylin and of its reverse sequence. The spontaneous formation of protofibrils and their orientation along well-defined directions on graphite and DMSO-coated graphite substrates make the studied peptides interesting candidates for nanotechnological applications. The measured binding forces between peptides correlate with the number of hydrogen bonds between individual peptides inside the fibril structure according to molecular dynamics simulations ...
Currently, there is a growing need for methods that can quantify and map the molecular interactions of biological samples, both with high-force sensitivity and high spatial resolution. Force-distance (FD) curve-based atomic force microscopy is a valuable tool to simultaneously contour the surface and map the biophysical properties of biological samples at the nanoscale. In this webinar, we will report the use of advanced FD-based technology combined with chemically functionalized tips to probe the localization and interactions of chemical and biological sites on single native proteins and on living cells at high-resolution. I will present how an atomic force and confocal microscopy set-up allows the surface receptor landscape of cells to be imaged and the virus binding events within the first millisecond of contact with the cell to be mapped at high resolution (,50 nm). I will also highlight theoretical approaches to contour the free-energy landscape of early binding events between an engineered ...
TY - GEN. T1 - Order in crystalline cellulose detected by atomic force microscopy (AFM). AU - Kuutti, Lauri. AU - Pere, Jaakko. AU - Peltonen, Jouko. AU - Teleman, Olle. N1 - Project code: BEL3009. PY - 1995. Y1 - 1995. N2 - In this work we applied AFM for the surface study of cellulose microcrystals using highly crystalline Valonia macrophysa vesicles as the substrate. Vesicles were pretreated with dilute alkali and an excess of distilled water prior to imaging with AFM. An AFM image of a vesicle showed a group of closely packed microcrystals. A more detailed image of the membrane was also obtained. In the area of 14 × 14 nm2 the surface roughness was typically 1 nm. We calculated the two-dimensional fast fourier transform (FFT) of the raw data and obtained crystal parameters as well as a highly filtered inverse-transformed image. This image showed a periodicity of 1.01 nm, which may correspond to the fibre repeat unit length. Molecular modelling was used to generate a Connolly model surface ...
Deflection images of living outer Annulus cells from Bovine Intervertebral discs, day 6 (after seeding), imaged in culture medium containing 10% fetal bovine serum (FBS) using Contact Mode. Left image was acquired before a series of force curves were taken on the area of the cell that is circled in red. Right image was acquired 45 minutes later. Displayed force curve was acquired on the cell marked with an X. It can be clearly seen that the cells have moved, undergone cytoskeletal reorganization and, where the force curves were taken, were damaged by the AFM tip, 54µm.. Data Courtesy of Y. Dror and J. Klein, Oxford University and Weizmann Institute, NanoInteract consortium.. ...
Abstract: This thesis uses a Veeco Icon Atomic Force Microscope (AFM) to educate undergraduate students about the nanoscale world and to perform archaeological research. In chapter 2, an educational resource is developed to provide hands-on nanotechnology experience for undergraduate students. With the rapid growth of atomic force microscopy at many levels of industry and academia, it is important to expose the next generation to this technique. This learning module attempts to provide an experimental approach to learning about AFM phase imaging and its many applications. In chapters 3 and 4, AFM is used as one of several techniques for classifying the use of Neanderthal flint tools from Weasel Cave, Russia. These stone tools were identified as being used for tasks such as wood working, hide scraping, and meat cutting. Depending on the type of flint and the task involved, various degrees of abrasion occurred, leaving behind microwear polishes. These microwear traces are localized regions where ...