scholarly journals Gels of Amyloid Fibers

Biomolecules ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 210 ◽  
Author(s):  
Ruizhi Wang ◽  
Xiaojing Yang ◽  
Lingwen Cui ◽  
Hang Yin ◽  
Shaohua Xu
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Atomic Force Microscopy ◽  
Melting Point ◽  
Protein Concentration ◽  
Size Exclusion ◽  
Amyloid Fibers ◽  
Force Microscopy ◽  
Atomic Force ◽  
3D Network

Protein self-assembly and formation of amyloid fibers is an early event of numerous human diseases. Continuous aggregation of amyloid fibers in vitro produces biogels, which led us to suspect that amyloid plaques and neurofibrillary tangles in Alzheimer’s disease are of biogels in nature. We applied atomic force microscopy, size exclusion chromatography, and differential scanning calorimetry to elucidate the gel’s structure, kinetics of gel formation, and melting point. We found that (1) lysozyme gelation occurs when the protein concentration is above 5 mg/mL; (2) nonfibrous protein concentration decreases and plateaus after three days of gel synthesis reaction; (3) colloidal lysozyme aggregates are detectable by both atomic force microscopy (AFM) and fast protein liquid chromatography (FPLC); (4) the gels are a three-dimensional (3D) network crosslinked by fibers coiling around each other; (5) the gels have a high melting point at around around 110 °C, which is weakly dependent on protein concentration; (6) the gels are conductive under an electric field, and (7) they form faster in the presence than in the absence of salt in the reaction buffer. The potential role of the gels formed by amyloid fibers in amyloidosis, particularly in Alzheimer’s disease was thoroughly discussed, as gels with increased viscosity, are known to restrict bulk flow and then circulation of ions and molecules.

P3-038: Atomic Force Microscopy to Study Molecular Mechanisms of Alzheimer's Disease

2016 ◽  
Vol 12 ◽  
pp. P832-P832
Author(s):  
Elizabeth Drolle ◽  
Francis Hane ◽  
Morgan Robinson ◽  
Jennifer Lou ◽  
Brenda Yasie Lee ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Atomic Force Microscopy ◽  
Molecular Mechanisms ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals High speed atomic force microscopy to investigate the interactions between toxic Aβ1-42 peptides and model membranes in real time: impact of the membrane composition

Nanoscale ◽  
2019 ◽  
Vol 11 (15) ◽  
pp. 7229-7238 ◽  
Author(s):  
M. Ewald ◽  
S. Henry ◽  
E. Lambert ◽  
C. Feuillie ◽  
C. Bobo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Atomic Force Microscopy ◽  
Real Time ◽  
High Speed ◽  
Model Membranes ◽  
Membrane Composition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Disease Mechanisms ◽  
Toxic Peptides

For investigating Alzheimer's disease mechanisms, high-speed atomic force microscopy is a proper tool to monitor the interactions between toxic peptides and lipid model membranes.

scholarly journals Nanoscale surface structures of DNA bound to Deinococcus radiodurans HU unveiled by atomic force microscopy

Nanoscale ◽  
2020 ◽  
Vol 12 (44) ◽  
pp. 22628-22638
Author(s):  
Shu-wen W. Chen ◽  
Anne-Sophie Banneville ◽  
Jean-Marie Teulon ◽  
Joanna Timmins ◽  
Jean-Luc Pellequer
Keyword(s):  
Atomic Force Microscopy ◽  
Protein Concentration ◽  
Deinococcus Radiodurans ◽  
Surface Structures ◽  
Force Microscopy ◽  
Naked Dna ◽  
Hu Protein ◽  
Double Stranded Dna ◽  
Atomic Force ◽  
Afm Imaging

AFM imaging reveals that Deinococcus radiodurans HU protein exerts a dual functionality by condensing and de-condensing double-stranded DNA plasmids depending on naked DNA configuration and the protein concentration.

scholarly journals Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid beta 1-42

2019 ◽  
Vol 2 (2) ◽  
pp. 48 ◽  
Author(s):  
Priya Prakash ◽  
Travis C. Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Beta ◽  
High Performance ◽  
Force Microscopy ◽  
Atomic Force ◽  
Short Period ◽  
One Step

Amyloid plaques found in the brains of Alzheimer’s disease patients primarily consists of amyloid beta 1-42 (Aβ42). Commercially, Aβ42 is synthesized using high-throughput peptide synthesizers resulting in the presence of impurities and the racemization of amino acids that affects its aggregation properties. Furthermore, the repeated purchase of even a small quantity (~1 mg) of commercial Aβ42 can be expensive for academic researchers. Here, we describe a detailed methodology for robust expression of recombinant human Aβ(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli using standard molecular biology techniques with refined and rapid one-step analytical purification techniques. The peptide is isolated and purified from transformed cells using an optimized reverse-phase high-performance liquid chromatography (HPLC) protocol with commonly available C18 columns, yielding high amounts of peptide (~15–20 mg per 1 L culture) within a short period of time. The recombinant human Aβ(M1-42) forms characteristic aggregates similar to synthetic Aβ42 aggregates as verified by western blotting and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique produces pure recombinant human Aβ(M1-42) that may be used to synthesize chemical probes and in several downstream in vitro and in vivo assays to facilitate Alzheimer’s disease research.

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