27 research outputs found
Template-Assisted Lateral Growth of Amyloid-β42 Fibrils Studied by Differential Labeling with Gold Nanoparticles
Amyloid-β protein (Aβ) aggregation into amyloid
fibrils
is central to the origin and development of Alzheimer’s disease
(AD), yet this highly complex process is poorly understood at the
molecular level. Extensive studies have shown that Aβ fibril
growth occurs through fibril elongation, whereby soluble molecules
add to the fibril ends. Nevertheless, fibril morphology strongly depends
on aggregation conditions. For example, at high ionic strength, Aβ
fibrils laterally associate into bundles. To further study the mechanisms
leading to fibril growth, we developed a single-fibril growth assay
based on differential labeling of two Aβ42 variants with gold
nanoparticles. We used this assay to study Aβ42 fibril growth
under different conditions and observed that bundle formation is preceded
by lateral interaction of soluble Aβ42 molecules with pre-existing
fibrils. Based on this data, we propose template-assisted lateral
fibril growth as an additional mechanism to elongation for Aβ42
fibril growth
Amount of DKP, diclofenac, DKP-diclofenac conjugate, TAT-diclofenac conjugate and TAT in the skin after permeation experiments (donor amount of 150 μg).
<p>Data is represented as mean ± sem (n = 4), * P<0.05.</p
Human skin permeation of diclofenac alone, diclofenac as admixture with DKP, diclofenac as DKP conjugate and diclofenac as TAT conjugate.
<p>The data is represented as mean ± sem (n = 5), *P<0.05.</p
Representation of the linker system used in the (a) <i>C</i>-terminal analogs (b) <i>N</i>-terminal analogs.
<p>Representation of the linker system used in the (a) <i>C</i>-terminal analogs (b) <i>N</i>-terminal analogs.</p
RP-HPLC Chromatogram of the enzymatic evaluation of the model substrate.
<p>Conditions: lineal gradient of 0–100% MeCN (0.036% TFA) in H<sub>2</sub>O (0.045% TFA) in 15 min. Flux of 1 mL/min, in a symmetry column C<sub>18</sub> (4.6 mm×150 mm), Waters, 100 Å, 5 µm, detection at 220 nm.</p
Summary of permeation data for diclofenac and peptide shuttles.
<p>Summary of permeation data for diclofenac and peptide shuttles.</p
Representation of the peptide bound to PEGA<sub>1900</sub> resin using the PLL linker (drawn in green).
<p>Representation of the peptide bound to PEGA<sub>1900</sub> resin using the PLL linker (drawn in green).</p
Representation of (a) the model substrate, (b) the <i>C</i>-terminal-anchored analogs and control peptides, (c) the <i>N</i>-terminal-anchored analogs and control peptides.
<p>Representation of (a) the model substrate, (b) the <i>C</i>-terminal-anchored analogs and control peptides, (c) the <i>N</i>-terminal-anchored analogs and control peptides.</p
Representation of the peptides used to confirm the esterase activity and capacity to process on solid-phase.
<p>(a) <i>C</i>-terminal-anchored analogs directly bounded on solid-phase. (b) <i>C</i>-terminal control peptides for the fluorescence assay directly bounded on solid-phase.</p
Characteristics and performance of the tested algorithms.
<p>The scoring function in the deterministic algorithms is based on achieving zero signal overlap (<i>Scoring = Ni</i>, where N<sub>i</sub>: number of fragments in the mixture) while in stochastic algorithms the scoring function is based on achieving minimal signal overlap (, where N<sub>ov</sub>: number of overlapped signals of compound <i>i</i>, and N<sub>t</sub>: total number of signals of compound <i>i</i>).</p