Synthesis of Photopolymerizable Glycolipids and their Application as Scaffolds to Immobilize Proteins with a Micron-Sized Pattern

2003 ◽  
Vol 56 (6) ◽  
pp. 567 ◽  
Author(s):  
Noriko Nagahori ◽  
Kenichi Niikura ◽  
Reiko Sadamoto ◽  
Kenji Monde ◽  
Shin-Ichiro Nishimura
Keyword(s):  
Protein Interactions ◽  
Binding Sites ◽  
Membrane Surface ◽  
Carbohydrate Binding ◽  
Protein Patterns ◽  
Force Microscopy ◽  
Atomic Force ◽  
Air Water Interface ◽  
Carbohydrate Ligands ◽  
Carbohydrate Binding Proteins

Photopolymerizable glycolipids incorporating ceramide- or amido-type linkers and able to form stable monolayers were efficiently synthesized by chemical and enzymatic methods. Glycolipid polymer films served as platforms for the immobilization of proteins through specific carbohydrate–protein interactions at the air–water interface. Carbohydrate-binding proteins deposited on the glycolipid film were observed by atomic force microscopy, which showed varying submicron-sized protein patterns such as dendrites, dots, and networks, depending on the lipid structure, membrane preparation process, and sugar density of the membrane. Surface plasmon resonance measurement confirmed that the subunit-type lectins immobilized on the glycolipid membranes exhibited the ability to interact specifically with carbohydrate ligands by using unoccupied binding sites.

scholarly journals Identification of lectin receptors for conserved SARS-CoV-2 glycosylation sites

2021 ◽  
Author(s):  
David Hoffmann ◽  
Stefan Mereiter ◽  
Yoo Jin Oh ◽  
Vanessa Monteil ◽  
Rong Zhu ◽  
...  
Keyword(s):  
Single Molecule ◽  
Viral Entry ◽  
Therapeutic Interventions ◽  
Carbohydrate Binding ◽  
Cell Surfaces ◽  
Lectin Receptors ◽  
Force Microscopy ◽  
Atomic Force ◽  
Glycosylation Sites ◽  
Carbohydrate Binding Proteins

AbstractNew SARS-CoV-2 variants are continuously emerging with critical implications for therapies or vaccinations. All 22 N-glycan sites of SARS-CoV-2 Spike remain highly conserved among the variants B.1.1.7, 501Y.V2 and P.1, opening an avenue for robust therapeutic intervention. Here we used a comprehensive library of mammalian carbohydrate-binding proteins (lectins) to probe critical sugar residues on the full-length trimeric Spike and the receptor binding domain (RBD) of SARS-CoV-2. Two lectins, Clec4g and CD209c, were identified to strongly bind to Spike. Clec4g and CD209c binding to Spike was dissected and visualized in real time and at single molecule resolution using atomic force microscopy. 3D modelling showed that both lectins can bind to a glycan within the RBD-ACE2 interface and thus interferes with Spike binding to cell surfaces. Importantly, Clec4g and CD209c significantly reduced SARS-CoV-2 infections. These data report the first extensive map and 3D structural modelling of lectin-Spike interactions and uncovers candidate receptors involved in Spike binding and SARS-CoV-2 infections. The capacity of CLEC4G and mCD209c lectins to block SARS-CoV-2 viral entry holds promise for pan-variant therapeutic interventions.

Phase Transitions in Phospholipid Monolayers Studied by Atomic Force Microscopy and Langmuir-Blodgett Technique

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Maria Tomoaia-Cotisel ◽  
Aurora Mocanu
Keyword(s):  
Atomic Force Microscopy ◽  
Lipid Membrane ◽  
Phase Behaviour ◽  
Membrane Interface ◽  
Force Microscopy ◽  
Langmuir Blodgett ◽  
Atomic Force ◽  
Phospholipid Monolayers ◽  
Air Water Interface ◽  
Condensed Liquid

The phase behaviour and surface structure of dipalmitoyl phosphatidyl choline (DPPC) monolayers at the air/water interface, in the absence and the presence of procaine, have been investigated by Langmuir-Blodgett (LB) technique and atomic force microscopy. The LB films were transferred on mica, at a controlled surface pressure, characteristic for the expanded liquid to condensed liquid phase transition of pure DPPC monolayers. The results indicate that procaine penetrates into and specifically interacts with phospholipid monolayers stabilizing the lipid membrane interface.

Mechanical Properties of Membrane Surface of Cultured Astrocyte Revealed by Atomic Force Microscopy

2000 ◽  
Vol 39 (Part 1, No. 6B) ◽  
pp. 3711-3716 ◽  
Author(s):  
Hatsuki Shiga ◽  
Yukako Yamane ◽  
Etsuro Ito ◽  
Kazuhiro Abe ◽  
Kazushige Kawabata ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Membrane Surface ◽  
Force Microscopy ◽  
Atomic Force

Visualization of molecular binding sites at the nanoscale in the lift-up mode by amplitude-modulation atomic force microscopy

Nanoscale ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 4213-4220
Author(s):  
Tatsuhiro Maekawa ◽  
Takashi Nyu ◽  
Evan Angelo Quimada Mondarte ◽  
Hiroyuki Tahara ◽  
Kasinan Suthiwanich ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Molecular Recognition ◽  
Amplitude Modulation ◽  
Binding Sites ◽  
Local Distribution ◽  
New Approach ◽  
Molecular Binding ◽  
Force Microscopy ◽  
Atomic Force ◽  
Recognition Sites

We report a new approach to visualize the local distribution of molecular recognition sites with nanoscale resolution by amplitude-modulation atomic force microscopy.

Image enhancement of polyethersulfone ultrafiltration membrane surface structure for atomic force microscopy

1992 ◽  
Vol 46 (1) ◽  
pp. 167-178 ◽  
Author(s):  
A. K. Fritzsche ◽  
A. R. Arevalo ◽  
M. D. Moore ◽  
C. J. Weber ◽  
V. B. Elings ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Structure ◽  
Image Enhancement ◽  
Membrane Surface ◽  
Ultrafiltration Membrane ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Lectins at Interfaces—An Atomic Force Microscopy and Multi-Parameter-Surface Plasmon Resonance Study

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2348 ◽  
Author(s):  
Katrin Niegelhell ◽  
Thomas Ganner ◽  
Harald Plank ◽  
Evelyn Jantscher-Krenn ◽  
Stefan Spirk
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Plasmon Resonance ◽  
Protein Adsorption ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Resonance Spectroscopy ◽  
Carbohydrate Binding ◽  
Force Microscopy ◽  
Atomic Force ◽  
Slow Kinetics

Lectins are a diverse class of carbohydrate binding proteins with pivotal roles in cell communication and signaling in many (patho)physiologic processes in the human body, making them promising targets in drug development, for instance, in cancer or infectious diseases. Other applications of lectins employ their ability to recognize specific glycan epitopes in biosensors and glycan microarrays. While a lot of research has focused on lectin interaction with specific carbohydrates, the interaction potential of lectins with different types of surfaces has not been addressed extensively. Here, we screen the interaction of two specific plant lectins, Concanavalin A and Ulex Europaeus Agglutinin-I with different nanoscopic thin films. As a control, the same experiments were performed with Bovine Serum Albumin, a widely used marker for non-specific protein adsorption. In order to test the preferred type of interaction during adsorption, hydrophobic, hydrophilic and charged polymer films were explored, such as polystyrene, cellulose, N,-N,-N-trimethylchitosan chloride and gold, and characterized in terms of wettability, surface free energy, zeta potential and morphology. Atomic force microscopy images of surfaces after protein adsorption correlated very well with the observed mass of adsorbed protein. Surface plasmon resonance spectroscopy studies revealed low adsorbed amounts and slow kinetics for all of the investigated proteins for hydrophilic surfaces, making those resistant to non-specific interactions. As a consequence, they may serve as favorable supports for biosensors, since the use of blocking agents is not necessary.

scholarly journals A Systematic Study of Ammonia Recovery from Anaerobic Digestate Using Membrane-Based Separation

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 19
Author(s):  
Fanny Rivera ◽  
Raúl Muñoz ◽  
Pedro Prádanos ◽  
Antonio Hernández ◽  
Laura Palacio
Keyword(s):  
Flow Rate ◽  
Membrane Surface ◽  
H2so4 Solution ◽  
Membrane Area ◽  
Recirculation Flow ◽  
Force Microscopy ◽  
Reservoir Volume ◽  
Atomic Force ◽  
Flat Sheet ◽  
Ammonia Recovery

Ammonia recovery from synthetic and real anaerobic digestates was accomplished using hydrophobic flat sheet membranes operated with H2SO4 solutions to convert ammonia into ammonium sulphate. The influence of the membrane material, flow rate (0.007, 0.015, 0.030 and 0.045 m3 h−1) and pH (7.6, 8.9, 10 and 11) of the digestate on ammonia recovery was investigated. The process was carried out with a flat sheet configuration at a temperature of 35 °C and with a 1 M, or 0.005 M, H2SO4 solution on the other side of the membrane. Polytetrafluoroethylene membranes with a nominal pore radius of 0.22 µm provided ammonia recoveries from synthetic and real digestates of 84.6% ± 1.0% and 71.6% ± 0.3%, respectively, for a membrane area of 8.6 × 10−4 m2 and a reservoir volume of 0.5 L, in 3.5 h with a 1 M H2SO4 solution and a recirculation flow on the feed side of the membrane of 0.030 m3 h−1. NH3 recovery followed first order kinetics and was faster at higher pHs of the H2SO4 solution and recirculation flow rate on the membrane feed side. Fouling resulted in changes in membrane surface morphology and pore size, which were confirmed by Atomic Force Microscopy and Air Displacement Porometry.

Structural and Morphological Characterization of Ultrathin Films of an Asymmetric Polydiacetylene

1996 ◽  
Vol 440 ◽  
Author(s):  
H. C. Wang ◽  
D. W. Cheong ◽  
J. Kumar ◽  
C. Sung ◽  
S. K. Tripathy
Keyword(s):  
Second Harmonic ◽  
Morphological Characterization ◽  
Lb Films ◽  
Force Microscopy ◽  
Langmuir Blodgett ◽  
Glass Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Air Water Interface

AbstractA soluble, asymmetrically substituted polydiacetylene, poly(BPOD), has been reported to form stable monolayers at the air-water interface by the Langmuir-Blodgett (LB) technique [2]. Preformed polydiacetylene has been deposited onto hydrophobic substrates as multilayers to form second order nonlinear optical thin films. Second harmonic generation was found to increase with the number of layers. From previous atomic force microscopy (AFM) studies backbone orientation along the dipping direction with an interchain spacing of about 5 A° was indicated [2].The film morphology and preferential molecular orientation of these LB films are further investigated by transmission electron microscopy (TEM). A specifically tailored sample preparation method for the ultrathin LB films was used. Multilayer films were deposited on hydrophobic collodion covered glass substrates for this purpose. Electron diffraction was employed to study the crystalline organization of mono and multilayers of LB films as well as cast films.

scholarly journals AFM and FluidFM Technologies: Recent Applications in Molecular and Cellular Biology

Scanning ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Yassine Amarouch ◽  
Jaouad El Hilaly ◽  
Driss Mazouzi
Keyword(s):  
Single Cell ◽  
Protein Interactions ◽  
Single Cells ◽  
Cardiac Cells ◽  
Cellular Biology ◽  
Adhesion Forces ◽  
Cell Organelles ◽  
Force Microscopy ◽  
Imaging Tool ◽  
Atomic Force

Atomic force microscopy (AFM) is a widely used imaging technique in material sciences. After becoming a standard surface-imaging tool, AFM has been proven to be useful in addressing several biological issues such as the characterization of cell organelles, quantification of DNA-protein interactions, cell adhesion forces, and electromechanical properties of living cells. AFM technique has undergone many successful improvements since its invention, including fluidic force microscopy (FluidFM), which combines conventional AFM with microchanneled cantilevers for local liquid dispensing. This technology permitted to overcome challenges linked to single-cell analyses. Indeed, FluidFM allows isolation and injection of single cells, force-controlled patch clamping of beating cardiac cells, serial weighting of micro-objects, and single-cell extraction for molecular analyses. This work aims to review the recent studies of AFM implementation in molecular and cellular biology.

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