scholarly journals Characterization by Nano-Infrared Spectroscopy of Individual Aggregated Species of Amyloid Proteins

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2899 ◽  
Author(s):  
Jehan Waeytens ◽  
Vincent Van Hemelryck ◽  
Ariane Deniset-Besseau ◽  
Jean-Marie Ruysschaert ◽  
Alexandre Dazzi ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Spatial Resolution ◽  
Amyloid Fibrils ◽  
Thin Layers ◽  
Fibrillar Structure ◽  
Native Structure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Innovative Tool ◽  
Β Sheet

Amyloid fibrils are composed of aggregated peptides or proteins in a fibrillar structure with a higher β-sheet content than in their native structure. To characterize them, we used an innovative tool that coupled infrared spectroscopy with atomic force microscopy (AFM-IR). With this method, we show that we can detect different individual aggregated species from oligomers to fibrils and study their morphologies by AFM and their secondary structures based on their IR spectra. AFM-IR overcomes the weak spatial resolution of usual infrared spectroscopy and achieves a resolution of ten nanometers, the size of isolated fibrils. We characterized oligomers, amyloid fibrils of Aβ42 and fibrils of α-synuclein. To our surprise, we figured out that the nature of some surfaces (ZnSe) used to study the samples induces destructuring of amyloid samples, leading to amorphous aggregates. We strongly suggest taking this into consideration in future experiments with amyloid fibrils. More importantly, we demonstrate the advantages of AFM-IR, with a high spatial resolution (≤ 10 nm) allowing spectrum recording on individual aggregated supramolecular entities selected thanks to the AFM images or on thin layers of proteins.

scholarly journals The Infuence of Salicin on Rheological and Film-Forming Properties of Collagen

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1661
Author(s):  
Katarzyna Adamiak ◽  
Katarzyna Lewandowska ◽  
Alina Sionkowska
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Infrared Spectroscopy ◽  
Rheological Properties ◽  
Silver Carp ◽  
Shear Tests ◽  
Force Microscopy ◽  
Atomic Force ◽  
Film Forming ◽  
Potential Applications

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.

High-Spatial-Resolution Topographic Imaging and Dimer Distance Analysis of Si(100)-(2×1) Using Noncontact Atomic Force Microscopy

2008 ◽  
Vol 47 (7) ◽  
pp. 6085-6087 ◽  
Author(s):  
Daisuke Sawada ◽  
Takashi Namikawa ◽  
Masuhiro Hiragaki ◽  
Yoshiaki Sugimoto ◽  
Masayuki Abe ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Force Microscopy ◽  
Distance Analysis ◽  
Atomic Force ◽  
Topographic Imaging

Structural evolution and acoustic phonon behavior in crystalline PTFE latex films

2003 ◽  
Vol 779 ◽  
Author(s):  
M. Pierno ◽  
C.S. Casari ◽  
A. Li Bassi ◽  
M.G. Beghi ◽  
R. Piazza ◽  
...  
Keyword(s):  
Structural Evolution ◽  
Crystalline Polymer ◽  
Model Systems ◽  
Fibrillar Structure ◽  
Sintering Process ◽  
Latex Films ◽  
Force Microscopy ◽  
Crystalline Polymers ◽  
Atomic Force ◽  
Acoustic Excitations

AbstractThe structural evolution of polytetrafluoroethylene (PTFE) crystalline polymer latex films is studied at hundreds nanometer length scale by atomic force microscopy and Brillouin light scattering. In a controlled sintering process the transition is observed from the original particle distribution towards a ‘fibrillar’ structure of crystalline regions embedded in a disordered matrix. This transition is accompanied by a cross-over from localized acoustic excitations to propagating acoustic phonons, related to mesoscopic elastic properties. After sintering, a ‘mark’ of the original particulate structure persists, suggesting that filming of crystalline polymers may be analogous to sintering of ceramic powders. Films of crystalline polymers can thus be exploited as model systems to study the elasto-optical properties of granular and disordered media.

Effect of curcumin on amyloidogenic property of molten globule-like intermediate state of 2,5-diketo-d-gluconate reductase A

2009 ◽  
Vol 390 (10) ◽  
Author(s):  
Nandini Sarkar ◽  
Abhay Narain Singh ◽  
Vikash Kumar Dubey
Keyword(s):  
Protein Concentration ◽  
Molten Globule ◽  
Molar Ratio ◽  
Amyloid Formation ◽  
Molten Globule State ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sheet Structure ◽  
Amyloid Diseases ◽  
Β Sheet

Abstract We identified a molten globule-like intermediate of 2,5-diketo-d-gluconate reductase A (DKGR) at pH 2.5, which has a prominent β-sheet structure. The molten globule state of the protein shows amyloidogenic property >50 μm protein concentration. Interestingly, a 1:1 molar ratio of curcumin prevents amyloid formation as shown by the Thioflavin-T assay and atomic force microscopy. To the best of our knowledge, this is the first report on amyloid formation by an (α/β)8-barrel protein. The results presented here indicate that the molten globule state has an important role in amyloid formation and potential application of curcumin in protein biotechnology as well as therapeutics against amyloid diseases.

The Investigation of Thin Protecting Layers on Roughened Galvanized Steel Surfaces Produced by Different Coating Methods

2008 ◽  
Vol 589 ◽  
pp. 433-438 ◽  
Author(s):  
Péter Németh ◽  
Ágnes Csanády ◽  
Katalin Papp ◽  
Anna C. Pintér ◽  
László Szabó ◽  
...  
Keyword(s):  
Thickness Distribution ◽  
Thin Layers ◽  
Galvanized Steel ◽  
Photoemission Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Coating Methods ◽  
Chemical States ◽  
Steel Surfaces ◽  
Thickness Variations

Protective, chromate substitute thin layers on roughened galvanized surfaces produced at OCAS (Arcelor, Belgium) were characterized and compared using Scanning Electron Microscopy (SEM+EDS), Atomic Force Microscopy (AFM), Nanoindentation and X-ray Photoemission Spectroscopy (XPS). EDX maps, line scans and point analyses obtained at various places of the surfaces have shown differences between the CVD and silane nanolayers in the matter of thickness distribution and composition. At cross-section specimens the thickness of the layers could be shown. The hardness differences caused by layer thickness variations are hard to follow by nanoindentation as the penetration depth of the indenter is much larger than the thickness of the coatings. XPS measurements can distinguish between the chemical states of silicon in CVD and silane coatings.

Sign in / Sign up

Export Citation Format

Share Document