The Elastic Properties of the Caulobacter crescentus Adhesive Holdfast Are Dependent on Oligomers of N-Acetylglucosamine

ABSTRACT The aquatic bacterium Caulobacter crescentus attaches to solid surfaces through an adhesive holdfast located at the tip of its polar stalk, a thin cylindrical extension of the cell membrane. In this paper, the elastic properties of the C. crescentus stalk and holdfast assembly were studied by using video light microscopy. In particular, the contribution of oligomers of N-acetylglucosamine (GlcNAc) to the elasticity of holdfast was examined by lysozyme digestion. C. crescentus cells attached to a surface undergo Brownian motion while confined effectively in a harmonic potential. Mathematical analysis of such motion enabled us to determine the force constant of the stalk-holdfast assembly, which quantifies its elastic properties. The measured force constant exhibits no dependence on stalk length, consistent with the theoretical estimate showing that the stalk can be treated as a rigid rod with respect to fluctuations of the attached cells. Therefore, the force constant of the stalk-holdfast assembly can be attributed to the elasticity of the holdfast. Motions of cells in a rosette were found to be correlated, consistent with the elastic characteristics of the holdfast. Atomic force microscopy analysis indicates that the height of a dried (in air) holdfast is approximately one-third of that of a wet (in water) holdfast, consistent with the gel-like nature of the holdfast. Lysozyme, which cleaves oligomers of GlcNAc, reduced the force constant to less than 10% of its original value, consistent with the polysaccharide gel-like nature of the holdfast. These results also indicate that GlcNAc polymers play an important role in the strength of the holdfast.

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TUNING PROPERTIES AND MORPHOLOGY IN HIGH VINYL CONTENT SBS BLOCK COPOLYMER, A THERMOPLASTIC ELASTOMER VIA THIOL-ENE MODIFICATION

Rubber Chemistry and Technology ◽

10.5254/rct.17.83761 ◽

2017 ◽

Vol 90 (3) ◽

pp. 550-561 ◽

Cited By ~ 2

Author(s):

Prithwiraj Mandal ◽

Siva Ponnupandian ◽

Soumyadip Choudhury ◽

Nikhil K. Singha

Keyword(s):

Block Copolymer ◽

Thermoplastic Elastomer ◽

Atomic Force Microscopy Analysis ◽

Ene Reaction ◽

Force Microscopy ◽

Atomic Force ◽

Microscopy Analysis ◽

Styrene Butadiene Styrene ◽

Styrene Butadiene ◽

Butadiene Styrene

ABSTRACT Thiol-ene modification of high vinyl content thermoplastic elastomeric styrene butadiene styrene (SBS) block copolymer (BCP) was carried out using different thiolating agents in toluene at 70 °C. 1H NMR analysis confirmed the participation of vinyl double bond in the thiol-ene modification reaction of SBS. Surface morphology of the block copolymers evaluated by atomic force microscopy analysis showed higher roughness after the thiol-ene reaction. The thiol-modified SBS block copolymer showed better adhesion strength and oil resistance properties than the pristine SBS.

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Atomic force microscopy analysis of native infectious and inactivated SARS-CoV-2 virions

Scientific Reports ◽

10.1038/s41598-021-91371-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sébastien Lyonnais ◽

Mathilde Hénaut ◽

Aymeric Neyret ◽

Peggy Merida ◽

Chantal Cazevieille ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Native Conformation ◽

Force Microscopy ◽

Enveloped Virus ◽

Atomic Force ◽

Afm Imaging ◽

Level 3 ◽

Microscopy Analysis ◽

Virus Morphology ◽

Nanoscale Level

AbstractSARS-CoV-2 is an enveloped virus responsible for the Coronavirus Disease 2019 (COVID-19) pandemic. Here, single viruses were analyzed by atomic force microscopy (AFM) operating directly in a level 3 biosafety (BSL3) facility, which appeared as a fast and powerful method to assess at the nanoscale level and in 3D infectious virus morphology in its native conformation, or upon inactivation treatments. AFM imaging reveals structurally intact infectious and inactivated SARS-CoV-2 upon low concentration of formaldehyde treatment. This protocol combining AFM and plaque assays allows the preparation of intact inactivated SARS-CoV-2 particles for safe use of samples out of level 3 laboratory to accelerate researches against the COVID-19 pandemic. Overall, we illustrate how adapted BSL3-AFM is a remarkable toolbox for rapid and direct virus analysis based on nanoscale morphology.

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Movements of Mycoplasma mobile gliding machinery detected by high-speed atomic force microscopy

10.1101/2021.01.28.428740 ◽

2021 ◽

Author(s):

Kohei Kobayashi ◽

Noriyuki Kodera ◽

Taishi Kasai ◽

Yuhei O Tahara ◽

Takuma Toyonaga ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Internal Structure ◽

Sodium Azide ◽

High Speed ◽

Atp Hydrolysis ◽

Solid Surfaces ◽

Force Microscopy ◽

Special Mechanism ◽

Atomic Force ◽

Internal Structures

ABSTRACTMycoplasma mobile, a parasitic bacterium, glides on solid surfaces, such as animal cells and glass by a special mechanism. This process is driven by the force generated through ATP hydrolysis on an internal structure. However, the spatial and temporal behaviors of the internal structures in living cells are unclear. In this study, we detected the movements of the internal structure by scanning cells immobilized on a glass substrate using high-speed atomic force microscopy (HS-AFM). By scanning the surface of a cell, we succeeded in visualizing particles, 2 nm in hight and aligned mostly along the cell axis with a pitch of 31.5 nm, consistent with previously reported features based on electron microscopy. Movements of individual particles were then analyzed by HS-AFM. In the presence of sodium azide, the average speed of particle movements was reduced, suggesting that movement is linked to ATP hydrolysis. Partial inhibition of the reaction by sodium azide enabled us to analyze particle behavior in detail, showing that the particles move 9 nm right, relative to the gliding direction, and 2 nm into the cell interior in 330 ms, then return to their original position, based on ATP hydrolysis.IMPORTANCEThe Mycoplasma genus contains bacteria generally parasitic to animals and plants. Some Mycoplasma species form a protrusion at a pole, bind to solid surfaces, and glide by a special mechanism linked to their infection and survival. The special machinery for gliding can be divided into surface and internal structures that have evolved from rotary motors represented by ATP synthases. This study succeeded in visualizing the real-time movements of the internal structure by scanning from the outside of the cell using an innovative high-speed atomic force microscope, and then analyzing their behaviors.

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Conducting tip atomic force microscopy analysis of aluminum oxide barrier defects decorated by electrodeposition

Applied Physics Letters ◽

10.1063/1.1415775 ◽

2001 ◽

Vol 79 (19) ◽

pp. 3158-3160 ◽

Cited By ~ 3

Author(s):

J. Carrey ◽

K. Bouzehouane ◽

J.-M. George ◽

C. Ceneray ◽

A. Fert ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Aluminum Oxide ◽

Atomic Force Microscopy Analysis ◽

Force Microscopy ◽

Atomic Force ◽

Microscopy Analysis ◽

Oxide Barrier

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A study of molecular adsorption of a cationic surfactant on complex surfaces with atomic force microscopy

The Analyst ◽

10.1039/c5an01941a ◽

2016 ◽

Vol 141 (3) ◽

pp. 1017-1026 ◽

Cited By ~ 6

Author(s):

I. Sokolov ◽

G. Zorn ◽

J. M. Nichols

Keyword(s):

Atomic Force Microscopy ◽

Cationic Surfactant ◽

Solid Surfaces ◽

Molecular Adsorption ◽

Complex Surfaces ◽

Force Microscopy ◽

Atomic Force ◽

Broad Interest

The study of molecular adsorption on solid surfaces is of broad interest.

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Determination of Punica granatum L. Carpellary membrane elastic properties using atomic force microscopy

Recent Advances in Multidisciplinary Applied Physics ◽

10.1016/b978-008044648-6/50020-3 ◽

2005 ◽

pp. 119-125

Author(s):

M MILLAN ◽

M GASQUE ◽

F GARCIADIEGO ◽

J CURIEL ◽

G RUIZ

Keyword(s):

Atomic Force Microscopy ◽

Elastic Properties ◽

Punica Granatum ◽

Force Microscopy ◽

Atomic Force ◽

Punica Granatum L

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Anomalous Interfacial Structuring of a Non-Halogenated Ionic Liquid: Effect of Substrate and Temperature

Colloids and Interfaces ◽

10.3390/colloids2040060 ◽

2018 ◽

Vol 2 (4) ◽

pp. 60 ◽

Cited By ~ 5

Author(s):

Milad Radiom ◽

Patricia Pedraz ◽

Georgia Pilkington ◽

Patrick Rohlmann ◽

Sergei Glavatskih ◽

...

Keyword(s):

Ionic Liquid ◽

Surface Charge ◽

Force Measurement ◽

Surface Force ◽

Solid Surfaces ◽

Effect Of Temperature ◽

Decay Length ◽

Force Microscopy ◽

Large Size ◽

Atomic Force

We investigate the interfacial properties of the non-halogenated ionic liquid (IL), trihexyl(tetradecyl)phosphonium bis(mandelato)borate, [P6,6,6,14][BMB], in proximity to solid surfaces, by means of surface force measurement. The system consists of sharp atomic force microscopy (AFM) tips interacting with solid surfaces of mica, silica, and gold. We find that the force response has a monotonic form, from which a characteristic steric decay length can be extracted. The decay length is comparable with the size of the ions, suggesting that a layer is formed on the surface, but that it is diffuse. The long alkyl chains of the cation, the large size of the anion, as well as crowding of the cations at the surface of negatively charged mica, are all factors which are likely to oppose the interfacial stratification which has, hitherto, been considered a characteristic of ionic liquids. The variation in the decay length also reveals differences in the layer composition at different surfaces, which can be related to their surface charge. This, in turn, allows the conclusion that silica has a low surface charge in this aprotic ionic liquid. Furthermore, the effect of temperature has been investigated. Elevating the temperature to 40 °C causes negligible changes in the interaction. At 80 °C and 120 °C, we observe a layering artefact which precludes further analysis, and we present the underlying instrumental origin of this rather universal artefact.

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