Ultrasonic force microscopy for nanomechanical characterization of early and late-stage amyloid-β peptide aggregation
نویسندگان
چکیده
The aggregation of amyloid-β peptides into protein fibres is one of the main neuropathological features of Alzheimer's disease (AD). While imaging of amyloid-β aggregate morphology in vitro is extremely important for understanding AD pathology and in the development of aggregation inhibitors, unfortunately, potentially highly toxic, early aggregates are difficult to observe by current electron microscopy and atomic force microscopy (AFM) methods, due to low contrast and variability of peptide attachment to the substrate. Here, we use a poly-L-Lysine (PLL) surface that captures all protein components from monomers to fully formed fibres, followed by nanomechanical mapping via ultrasonic force microscopy (UFM), which marries high spatial resolution and nanomechanical contrast with the non-destructive nature of tapping mode AFM. For the main putative AD pathogenic component, Aβ1-42, the PLL-UFM approach reveals the morphology of oligomers, protofibrils and mature fibres, and finds that a fraction of small oligomers is still present at later stages of fibril assembly.
منابع مشابه
Molecular Dynamics and Molecular Docking Studies on the Interaction between Four Tetrahydroxy Derivatives of Polyphenyls and Beta Amyloid
Interactions of 3,3',4,4'-tetrahydroxybiphenyl (BPT) and three isomeric 3,3",4,4"-tetrahydroxyterphenyls (OTT, MTT, PTT) with Alzheimer’s amyloid-β peptide (Aβ) were studied by molecular dynamics simulation and molecular docking. Structural parameters such as Root-mean-square derivations (RMSD), radial distribution function (RDF), helix percentage and other physical parameters were obtained. Th...
متن کاملPreparation and study of the inhibitory effect of nano-niosomes containing essential oil from artemisia absinthium on amyloid fibril formation
Objective(s): Artemisia absinthium is an aromatic, perennial small shrub that shows multiple medical benefits, including anticancerous, neuroprotective, antifungal, hepatoprotective, antidepressant and antioxidant properties. One of the effective approaches to treat Alzheimer’s disease is targeting amyloid aggregation by antiamyloid drugs. In the current research study, an excellent grouping of...
متن کاملIdentification of a Novel Parallel β‐Strand Conformation within Molecular Monolayer of Amyloid Peptide
The differentiation of protein properties and biological functions arises from the variation in the primary and secondary structure. Specifically, in abnormal assemblies of protein, such as amyloid peptide, the secondary structure is closely correlated with the stable ensemble and the cytotoxicity. In this work, the early Aβ33-42 aggregates forming the molecular monolayer at hydrophobic interfa...
متن کاملDirect electrochemical and AFM detection of amyloid-β peptide aggregation on basal plane HOPG.
Amyloidogenesis is associated with more than 30 human diseases, including Alzheimer's which is related to aggregation of β-amyloid peptide (Aβ). Here, consecutive stages of Aβ42 aggregation and amyloid fibril formation were followed electrochemically via oxidation of tyrosines in Aβ42 adsorbed on the basal plane graphite electrode and directly correlated with Aβ42 morphological changes observed...
متن کاملEffects of Dimethyl Sulfoxide and Mutations on the Folding of Abeta(25-35) Peptide: Molecular Dynamics Simulations
The 25-35 fragment of the amyloid β (Aβ) peptide is a naturally occurring proteolytic by-product of its larger parent molecule that retains the amyloid characteristics and toxicity of the full length parent molecule. Aggregation of this peptide occurs rapidly in aqueous solutions and thus characterization of its folding process is very difficult. In the present study, early stages of Aβ(25–35) ...
متن کامل