Search results for "Nanopores"
showing 10 items of 34 documents
Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl2O4 Ceramics
2021
H.K. and A.I.P. are grateful for the support from the COST Action CA17126. H.K. was also supported by the Ministry of Education and Science of Ukraine (project for young researchers No. 0119U100435). In addition, I.K. and H.K. were also supported by the National Research Foundation of Ukraine via project 2020.02/0217, while the research of A.I.P. was funded by the Latvian research council via the Latvian National Research Program under the topic ?High-Energy Physics and Accelerator Technologies?, Agreement No: VPP-IZM-CERN-2020/1-0002. In addition, the research of A.I.P. has been supported by the Latvian-Ukrainian Grant LV-UA/2021/5. The Institute of Solid State Physics, University of Latvi…
Repair of a Bacterial Small β-Barrel Toxin Pore Depends on Channel Width
2017
ABSTRACT Membrane repair emerges as an innate defense protecting target cells against bacterial pore-forming toxins. Here, we report the first paradigm of Ca2+-dependent repair following attack by a small β-pore-forming toxin, namely, plasmid-encoded phobalysin of Photobacterium damselae subsp. damselae. In striking contrast, Vibrio cholerae cytolysin, the closest ortholog of phobalysin, subverted repair. Mutational analysis uncovered a role of channel width in toxicity and repair. Thus, the replacement of serine at phobalysin´s presumed channel narrow point with the bulkier tryptophan, the corresponding residue in Vibrio cholerae cytolysin (W318), modulated Ca2+ influx, lysosomal exocytosi…
HPG pore: an efficient and scalable framework for nanopore sequencing data.
2016
The use of nanopore technologies is expected to spread in the future because they are portable and can sequence long fragments of DNA molecules without prior amplification. The first nanopore sequencer available, the MinION™ from Oxford Nanopore Technologies, is a USB-connected, portable device that allows real-time DNA analysis. In addition, other new instruments are expected to be released soon, which promise to outperform the current short-read technologies in terms of throughput. Despite the flood of data expected from this technology, the data analysis solutions currently available are only designed to manage small projects and are not scalable. Here we present HPG Pore, a toolkit for …
Label-Free Pyrophosphate Recognition with Functionalized Asymmetric Nanopores
2016
[EN] The label¿free detection of pyrophosphate (PPi) anions with a nanofluidic sensing device based on asymmetric nanopores is demonstrated. The pore surface is functionalized with zinc complexes based on two di(2¿picolyl)amine [bis(DPA)] moieties using carbodiimide coupling chemistry. The complexation of zinc (Zn2+) ion is achieved by exposing the modified pore to a solution of zinc chloride to form bis(Zn2+¿DPA) complexes. The chemical functionalization is demonstrated by recording the changes in the observed current¿voltage (I¿V) curves before and after pore modification. The bis(Zn2+¿DPA) complexes on the pore walls serve as recognition sites for pyrophosphate anion. The experimental re…
Detection of Amyloid-β Fibrils Using Track-Etched Nanopores: Effect of Geometry and Crowding
2021
Several neurodegenerative diseases have been linked to proteins or peptides that are prone to aggregate in different brain regions. Aggregation of amyloid-β (Aβ) peptides is recognized as the main cause of Alzheimer's disease (AD) progression, leading to the formation of toxic Aβ oligomers and amyloid fibrils. The molecular mechanism of Aβ aggregation is complex and still not fully understood. Nanopore technology provides a new way to obtain kinetic and morphological aspects of Aβ aggregation at a single-molecule scale without labeling by detecting the electrochemical signal of the peptides when they pass through the hole. Here, we investigate the influence of nanoscale geometry (conical an…
A new 8-oxo-7,8-2 ' deoxyguanosine nanoporous anodic alumina aptasensor for colorectal cancer diagnosis in blood and urine
2021
Many important human diseases, and especially cancer, have been related to the overproduction of 8-oxo-7,8-dihydro-2 '-deoxyguanosine (8-oxo-dG). This molecule is a product of oxidative stress processes over nucleophilic bases in DNA. In this work, an aptasensor for the rapid, selective and accurate detection of this oncomarker is presented. The aptasensor consists of a nanoporous anodic alumina material loaded with a dye and is functionalized with an aptamer-based "molecular gate". In the presence of target 8-oxo-dG, the capping aptamer displaces from the surface due to the high affinity of the analyte with the capping aptamer, thus inducing delivery of the preloaded fluorescent dye. In co…
Spectroelectrochemistry of cytochrome c and azurin immobilized in nanoporous antimony-doped tin oxide
2011
Stable immobilization of two redox proteins, cytochrome c and azurin, in a thin film of highly mesoporous antimony-doped tin oxide is demonstrated via UV-vis spectroscopic and electrochemical investigation.
Size-selective incorporation of DNA nanocages into nanoporous antimony-doped tin oxide materials.
2011
A conductive nanoporous antimony-doped tin oxide (ATO) powder has been prepared using the sol-gel method that contains three-dimensionally interconnected pores within the metal oxide and highly tunable pore sizes on the nanoscale. It is demonstrated that these porous materials possess the capability of hosting a tetrahedral-shaped DNA nanostructure of defined dimensions with high affinity. The tunability of pore size enables the porous substrate to selectively absorb the DNA nanostructures into the metal oxide cavities or exclude them from entering the surface layer. Both confocal fluorescence microscopy and solution FRET experiments revealed that the DNA nanostructures maintained their int…
Bioinspired self-assembly of tyrosinase-modified silicatein and fluorescent core-shell silica spheres.
2014
Inspired by the intermolecular cross-linking of mussel foot proteins and their adhesive properties, tyrosinase has been used to modify recombinant silicatein. DOPA/DOPAquinone-mediated cross-linking and interfacial interactions enhanced both self-assembly of silicatein building blocks and templating of core–shell silica spheres, resulting in fluorescent biomimetic silicatein–silica hybrid mesofibers.
Conical nanopores highlight the pro-aggregating effects of pyrimethanil fungicide on Aβ(1-42) peptides and dimeric splitting phenomena.
2022
International audience; The Aβ(1-42) aggregation is a key event in the physiopathology of Alzheimer's disease (AD). Exogenous factors such as environmental pollutants, and more particularly pesticides, can corrupt Aβ(1-42) assembly and could influence the occurrence and pathophysiology of AD. However, pesticide involvement in the early stages of Aβ(1-42) aggregation is still unknown. Here, we employed conical track-etched nanopore in order to analyse the Aβ(1-42) fibril formation in the presence of pyrimethanil, a widely used fungicide belonging to the anilinopyrimidine class. Our results evidenced a pro-aggregating effect of pyrimethanil on Aβ(1-42). Aβ(1-42) assemblies were successfully d…