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Wyniki wyszukiwania dla: nanoparticle-protein aggregation
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The Influence of the Parameters of a Gold Nanoparticle Deposition Method on Titanium Dioxide Nanotubes, Their Electrochemical Response, and Protein Adsorption
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Theoretical investigation of the structural insights of the interactions of γ-Fe2O3 nanoparticle with (EMIM TFSI) ionic liquid
PublikacjaOne of the possible applications of ionic liquids is to produce electricity from heat. The iron oxide nanoparticle is a potent electrical particle, which is expected to improve the heat’s efficiency to electricity conversion, however, it is prone to aggregation and sedimentation, which hamper its application. One of the methods to enhance the nanoparticle’s solubility and electrical properties is the use of a stabilizing component...
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Protein overproduction alters exosome secretion in Chinese hamster ovary cells
PublikacjaDespite the abundance of available cell lines, nearly 70% of all recombinant therapeutic proteins today are produced in Chi-nese hamster ovary (CHO) cells. The impact of protein overproduction on the secretion of exosomes by CHO cells has been investigated here. Increased secretion of extracellular vesicles (EVs) by protein overexpressing CHO cells was demonstrated with protein content assay, nanoparticle tracking analysis, and...
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Highly antifouling polymer-nanoparticle-nanoparticle/polymer hybrid membranes
PublikacjaWe introduce highly antifouling Polymer-Nanoparticle-Nanoparticle/Polymer (PNNP) hybrid membranes as multi-functional materials for versatile purification of wastewater. Nitrogen-rich polyethylenimine (PEI)-functionalized halloysite nanotube (HNT-SiO2-PEI) nanoparticles were developed and embedded in polyvinyl chloride (PVC) membranes for protein and dye filtration. Bulk and surface characteristics of the resulting HNT-SiO2-PEI...
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Influence of the ionic strength on the amyloid fibrillogenesis of hen egg white lysozyme
PublikacjaThe study investigates the role of the electrostatic interactions in the fibrillation of the hen egg white lysozyme (HEWL). In order to achieve this aim the influence of the cations Na+, Mg2+ and Al3+ on the amyloid fibril formation and amorphous aggregation was tested. The amyloids are formed in the solution without added salt but the Thioflavin T fluorescence gives the false-negative result. In these conditions, the HEWL fibrils...
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Nanoparticle Tracking Analysis of Urinary Extracellular Vesicle Proteins as a New Challenge in Laboratory Medicine
PublikacjaUrinary extracellular vesicle (uEV) proteins may be used as specific markers of kidney damage in various pathophysiological conditions. The nanoparticle-tracking analysis (NTA) appears to be the most useful method for the analysis of uEVs due to its ability to analyze particles below 300 nm. The NTA method has been used to measure the size and concentration of uEVs and also allows for a deeper analysis of uEVs based on their protein...
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Organic solvents aggregating and shaping structural folding of protein, a case study of the protease enzyme
PublikacjaLow solubility of reactants or products in aqueous solutions can result in the enzymatic catalytic reactions that can occur in non-aqueous solutions. In current study we investigated aqueous solutions containing different organic solvents / deep eutectic solvents (DESs) that can influence the protease enzyme's activity, structural, and thermal stabilities. Retroviral aspartic protease enzyme is responsible for the cleavage of the...
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Hydration of Simple Model Peptides in Aqueous Osmolyte Solutions
PublikacjaThe biology and chemistry of proteins and peptides are inextricably linked with water as the solvent. The reason for the high stability of some proteins or uncontrolled aggregation of others may be hidden in the properties of their hydration water. In this study, we investigated the effect of stabilizing osmolyte–TMAO (trimethylamine N-oxide) and destabilizing osmolyte–urea on hydration shells of two short peptides, NAGMA (N-acetyl-glycine-methylamide)...
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Improved cytotoxicity and preserved level of cell death induced in colon cancer cells by doxorubicin after its conjugation with iron-oxide magnetic nanoparticles
PublikacjaA promising strategy for overcoming the problem of limited efficacy in antitumor drug delivery and in drug release is the use of a nanoparticle-conjugated drug. Doxorubicin (Dox) anticancer chemotherapeutics has been widely studied in this respect, because of severe cardiotoxic side effects. Here, we investigated the cytotoxic effects, the uptake process, the changes in cell cycle progression and the cell death processes in the...
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Progress in targeting tumor cells by using drug-magnetic nanoparticles conjugate.
PublikacjaTo limit the cytotoxicity of anticancer drugs against healthy cells, an appropriate carrier should be synthesized to deliver the drug to the tumor tissue only. A good solution is to anchor a magnetic nanoparticle to the molecule of the drug and to use a properly directed external magnetic field. We have shown that the improved by us synthesis of the conjugate of doxorubicin with iron-oxide magnetic nanoparticles allows a substantial...
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Identification of antigen Ag43 in uropathogenic Escherichia coli Dr+ strains and defining its role in the pathogenesis of urinary tract infections
PublikacjaUrinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) are among the most common bacterial infectious diseases in the developed world. The urovirulence of UPEC is mainly associated with the surface-exposed fimbrial adhesins and adhesins of the autotransporter (AT) family. The best studied of theses proteins is antigen 43 (Ag43) mediating cell aggregation, adhesion and biofilm development as the causes of...
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Two bacterial small heat shock proteins, IbpA and IbpB, form a functional heterodimer
PublikacjaSmall heat shock proteins (sHsps) are a conserved class of ATP-independent chaperones which in stress conditions bind to unfolded protein substrates and prevent their irreversible aggregation. Substrates trapped in sHsps-containing aggregates are efficiently refolded into native structures by ATP-dependent Hsp70 and Hsp100 chaperones. Most γ-proteobacteria possess a single sHsp (IbpA), while in a subset of Enterobacterales, as...
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Phage-Directed Synthesis of Photoluminescent Zinc Oxide Nanoparticles under Benign Conditions
PublikacjaBiological systems, especially bacteriophages and peptides, are an attractive green alternative to other known methods of nanoparticle synthesis. In this work, for the first time, bacteriophages were employed to synthesize a specific peptide, capable of producing nanoparticles (NPs). Derivatives of M13 bacteriophage exposing a ZnO-binding peptide (TMGA-LGLKWPV) on either pIII or pVIII phage coat protein were constructed and used...
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Epoxy/Ionic Liquid-Modified Mica Nanocomposites: Network Formation–Network Degradation Correlation
PublikacjaWe synthesized pristine mica (Mica) and N-octadecyl-N’-octadecyl imidazolium iodide (IM) modified mica (Mica-IM), characterized it, and applied it at 0.1–5.0 wt.% loading to prepare epoxy nanocomposites. Dynamic differential scanning calorimetry (DSC) was carried out for the analysis of the cure potential and kinetics of epoxy/Mica and epoxy/Mica-IM curing reaction with amine curing agents at low loading of 0.1 wt.% to avoid particle...
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Studies on micellar aggregation of nonionic surfactants in imidazolium liquids
PublikacjaA number of imidazolium ionic liquids, with 2-8 carbon atoms in cation alkyl chains, and tetrafluoroborate, hexafluorophosphate, bis(trifluoromethylsulfony)imide and trifluoromethanesulfonate anions, were characterized for their ability to support micellar aggregation of nonionic surfactants in binary solutions.
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Aggregation of imidazoacridinones - spectroscopic and microcalorimetric approach
PublikacjaImidazoacridinones (IA) belong to a group of polycyclic heteroaromatic antitumor compounds. IA create the aggregated form in water solution. Self-association of substances is a very important phenomenon in many fields of applied chemistry. It is also fundamental model reaction of many kinds of molecular interactions such as the micelle formation of amphiphilic substances and the binding of small organic molecules to macromolecules....
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Aggregation of nonionic surfactants in imidazolium ionic liquids
PublikacjaMicellar aggregation of surfactants in aqueous solutions has been described in terms of the balance between dispersive interactions of the hydrocarbon part of the amphiphilic molecule, and the hydration and electrostatic repulsive effects of hydrophilic head group. Changing the interactions by replacing water with another polar solvent, such as amides or glycols, has been studied to a smaller extent (Singh, Saleem et al. 1980;...
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Linezolid-resistant Enterococcus faecium strains isolated from one hospital in Poland –commensals or hospital-adapted pathogens?
PublikacjaOne of the most pressing problems of enterococci infections is occurring resistance to linezolid, which is an antibiotic used in the treatment of infections caused by vancomycin-resistant strains (VRE). The main objective of our research was to investigate the relationship of 19 linezolid-resistant E. faecium isolates from 18 patients hospitalized at Clinical Hospital in Gdansk (Poland). One of the LZDREF was isolated in 2003...
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Aggregation properties of some zirconium phosphate loaded with dirhenium(III) complexes
PublikacjaOne of the important areas of modern science is the selection of the right forms of drug delivery. Layered inorganic nanoparticles, such as zirconium phosphate, have proven themselves well in this area. The study of the properties of these systems and methods of their preparation makes it possible to determine a rational technology of their manufacture, storage conditions as well as suggest a possible mechanism of therapeutic action....
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Entropy Production Associated with Aggregation into Granules in a Subdiffusive Environment
PublikacjaWe study the entropy production that is associated with the growing or shrinking of a small granule in, for instance, a colloidal suspension or in an aggregating polymer chain. A granule will fluctuate in size when the energy of binding is comparable to k_{B}T, which is the “quantum” of Brownian energy. Especially for polymers, the conformational energy landscape is often rough and has been commonly modeled as being self-similar...
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The influence of reactions conditions on aggregation of dyes used in biochemistry
PublikacjaSelf-association of dyes and related substances is a very important phenomenon in many fields of applied chemistry. It is also fundamental model reaction of many kinds of molecular interactions such as the micelle formation of amphiphilic substances and the binding of small organic molecules to macromolecules. In spite of many studies concerning the dimerization equilibria of dyes and related substances, the mechanism seems not...
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Effect of Temperature and Nanoparticle Concentration on Free Convective Heat Transfer of Nanofluids
PublikacjaA theoretical analysis of the influence of temperature and nanoparticle concentration on free convection heat transfer from a horizontal tube immersed in an unbounded nanofluid was presented. The Nusselt (Nu) number and heat transfer coefficient were parameters of the intensity of the convective heat transfer. For free convection, the Nu number was a function of the Rayleigh (Ra) number and Prandtl (Pr) number. The Rayleigh (Ra)...
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The Effect of Sterols on Amphotericin B Self-Aggregation in a Lipid Bilayer as Revealed by Free Energy Simulations
PublikacjaAmphotericin B (AmB) is an effective but toxic antifungal drug, known to increase the permeability of the cell membrane, presumably by assembling into transmembrane pores in a sterol-dependent manner. The aggregation of AmB molecules in a phospholipid bilayer is, thus, crucial for the drug’s activity. To provide an insight into the molecular nature of this process, here, we report an atomistic molecular dynamics simulation study...
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On the Origin of Protein Superfamilies and Superfolds
PublikacjaDistributions of protein families and folds in genomes are highly skewed, having a small number of prevalent superfamiles/superfolds and a large number of families/folds of a small size. Why are the distributions of protein families and folds skewed? Why are there only a limited number of protein families? Here, we employ an information theoretic approach to investigate the protein sequence-structure relationship that leads to...
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Impact damage in SiO2 nanoparticle enhanced epoxy – Carbon fibre composites
PublikacjaLow velocity impact behaviour of nano-SiO2 enhanced carbon fibre/epoxy composites for naval applications is reported. Epoxy resin matrix was enhanced by 1- 8 wt% SiO2 nanoparticles, based on industrial surface-modified nanosilica. Impact parameters: force, deformation, energy, damage size were recorded. The most pronounced effect was damage size decrease; e.g. ∼28% recorded by infrared thermography and X-ray computed radiography...
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Micellar aggregation of Triton X-100 surfactant in imidazolium ionic liquids
PublikacjaIn this work we investigated aggregation behavior of a nonionic surfactant Triton X-100 in eighteen imidazolium ionic liquids (ILs) with two to eight carbon atoms in cations alkyl chain, namely 1-ethyl-3-methylimidazolium, [EMIM], 1-butyl-3-methylimidazolium, [PrMIM], 3-methyl-1-propylimidazolium, [BMIM], 1-hexyl-3-methylimidazolium, [PMIM], 3-methyl-1-pentyl-imidazolium, [HMIM], and 1-octyl-3-methylimidazolium, [OMIM], and with...
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Influence of Osmolytes on Protein and Water Structure: A Step To Understanding the Mechanism of Protein Stabilization
PublikacjaResults concerning the thermostability of hen egg white lysozyme in aqueous solutions with stabilizing osmolytes, trimethylamine-N-oxide (TMAO), glycine (Gly), and its N-methyl derivatives, N-methylglycine (NMG), N,N-dimethylglycine (DMG), and N,N,N-trimethylglycine (betaine, TMG), have been presented. The combination of spectroscopic (IR) and calorimetric (DSC) data allowed us to establish a link between osmolytes’ influence on...
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The importance of the shape of the protein–water interface of a kinesin motor domain for dynamics of the surface atoms of the protein
PublikacjaA single kinesin motor domain immersed in water has been investigated using molecular dynamics. It has been found that local properties of water in the solvation shell change along with the nature of the neighboring protein surface. However, a detailed analysis leads to the conclusion that the geometrical features of hydrogen bonds and overall structure of kinesin hydration water are not very different from bulk water. The local...
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The importance of the shape of the protein-water interface of a kinesin motor domain for dynamics of the surface atoms of the protein
PublikacjaSingle kinesin motor domain immersed in water has been investigated using molecular dynamics. It has been found that local properties of water in solvation shell change along with the nature of neighboring protein surface. However, a detailed analysis leads to the conclusion that the geometrical features of hydrogen bonds and overall structure of kinesin hydration water is not very different from bulk water. The local values of...
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Modelling gene expression of a self-regulating protein
PublikacjaWe analyze a model of gene transcription and protein synthesis. We take into account the number of sites on the protein’s promoter at which the protein’s dimers can bind blocking transcription of protein mRNA.
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Platelets in fetal growth restriction: role of reactive oxygen species, oxygen metabolism, and aggregation.
PublikacjaFetal growth restriction (FGR) is mainly caused by failure of the uteroplacental unit. Theexact pathogenesis remains unclear. The cause is thought to be related to abnormal platelet activation,which may...
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Water absorption and blistering of glass fibre-reinforced polymer marine laminates with nanoparticle-modified coatings
PublikacjaMacro and microstructural damage was studied in typical glass fibre-reinforced polymer laminates with two types of coating systems – (a) isophtalic gel coat: pure or mixed with SiO2 nanoparticles 5 wt% (5%N) or 10 wt% (10%N) and (b) a two-layer coating system: urethane-modified vinyl ester-based gel coat and additional polyester barrier coat layer. Accelerated tests were performed at 50C for 50 days for specimens with nanoparticle-modified...
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Novel primosomal protein B from Clostridium pasteurianum
PublikacjaPriB is a primosomal protein that catalyzes DNA replication in Procaryota. The replication pathway starts with PriA protein - the initiator protein that binds to a DNA replication fork, unwinds double-stranded DNA and role of PriB is to stabilize PriA on the DNA. However there are many biochemical differences in replication mechanism in bacteria and only some of them use PriB proteins. A few of PriB proteins were published and...
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Novel primosomal protein B from Clostridium pastuerianum
PublikacjaPriB is a primosomal protein that catalyzes DNA replication in Procaryota. The replication pathway starts with PriA protein - the initiator protein that binds to a DNA replication fork, unwinds double-stranded DNA and role of PriB is to stabilize PriA on the DNA. However there are many biochemical differences in replication mechanism in bacteria and only some of them use PriB proteins. A few of PriB proteins were published and...
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Iron–Sulfur Cluster Biogenesis Chaperones: Evidence for Emergence of Mutational Robustness of a Highly Specific Protein–Protein Interaction
PublikacjaBiogenesis of iron–sulfur clusters (FeS) is a highly conserved process involving Hsp70 and J-protein chaperones. However, Hsp70 specialization differs among species. In most eukaryotes, including Schizosaccharomyces pombe, FeS biogenesis involves interaction between the J-protein Jac1 and the multifunctional Hsp70 Ssc1. But, in Saccharomyces cerevisiae and closely related species, Jac1 interacts with the specialized Hsp70 Ssq1,...
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Characterization of a single-stranded DNA-binding-like Protein from Nanoarchaeum equitans - a nucleic acid binding protein with broad substrate specificity
PublikacjaBackground SSB (single-stranded DNA-binding) proteins play an essential role in all living cells and viruses, as they are involved in processes connected with ssDNA metabolism. There has recently been an increasing interest in SSBs, since they can be applied in molecular biology techniques and analytical methods. Nanoarchaeum equitans, the only known representative of Archaea phylum Nanoarchaeota, is a hyperthermophilic, nanosized,...
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Emerging anticancer activity of candidal glucoseamine-6-phosphate synthase inhibitors upon nanoparticle-mediated delivery
PublikacjaNumerous glutamine analogues have been reported as irreversible inhibitors of the glucosamine-6-phosphate (GlcN-6-P) synthase in pathogenic Candida albicans in the last 3.5 decades. Among the reported inhibitors, the most effective N3-(4-methoxyfumaroyl)-L-2,3- diaminopropanoic acid (FMDP) has been extensively studied in order to develop its more active analogues. Several peptide−FMDP conjugates were tested to deliver FMDP to its...
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Problem of aggregation in dye-DNA interaction, calorimetry studies
PublikacjaNucleic acids are the biological target for many antimicrobial, antitumor and antiviral drugs. Ligand-DNA interactions can be classified into two major categories: 1. covalent binding, which can provide to intermolecular adducts, 2. physico-chemical interactions, which can be divided into intercalation (e.g. adriamycin) or groove binding (e.g. dystamycin). There are several methods to investigate interactions between drug and DNA....
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Energy-Optimal Data Aggregation and Dissemination for the Internet of Things
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Taurine as a water structure breaker and protein stabilizer
PublikacjaThe enhancing effect on the water structure has been confirmed for most of the osmolytes exhibiting both stabilizing and destabilizing properties in regard to proteins. The presented work concerns osmolytes, which should be classified as “structure breaking” solutes: taurine and N,N,N-trimethyltaurine (TMT). Here, we combine FTIR spectroscopy, DSC calorimetry and DFT calculations to gain an insight into the interactions between...
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Bacteriophages as Factories for Eu2O3 Nanoparticle Synthesis
PublikacjaThe use of phage display to identify peptides with an ability to bind and synthesize Eu2O3 nanoparticles is demonstrated in this report. This is the first report of modified phages specifically binding a lanthanide. The peptides exposed on virions revealed very strong binding to Eu2O3 nanoparticles and the ability to catalyze Eu2O3 nanoparticles’ formation from Eu(OH)3 and Eu(NO3)3 solutions. The luminescence emission spectrum...
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Impact of Temperature and Nanoparticle Concentration on Turbulent Forced Convective Heat Transfer of Nanofluids
PublikacjaTheoretical analysis of the influence of nanoparticles and temperature on the average Nusselt (Nu) number and the average heat transfer coefficient (HTC) during the turbulent flow of nanofluid in a horizontal, round tube was carried out. The Nu number is a function of the Reynolds (Re) number and the Prandtl (Pr) number, which in turn are functions of the thermophysical properties of the liquid and the flow conditions. On the other...
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Water-mediated influence of a crowded environment on internal vibrations of a protein molecule
PublikacjaThe influence of crowding on the protein inner dynamics is examined by putting a single protein molecule close to one or two neighboring protein molecules. The presence of additional molecules influences the amplitudes of protein fluctuations. Also, a weak dynamical coupling of collective velocities of surface atoms of proteins separated by a layer of water is detected. The possible mechanisms of these phenomena are described....
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Protein thermal stabilization in aqueous solutions of osmolytes
PublikacjaProteins’ thermal stabilization is a significant problem in various biomedical, biotechnological, and technological applications. We investigated thermal stability of hen egg white lysozyme in aqueous solutions of the following stabilizing osmolytes: Glycine (GLY), N-methylglycine (NMG), N,N-dimethylglycine (DMG), N,N,N-trimethylglycine (TMG), and trimethyl-N-oxide (TMAO). Results of CD-UV spectroscopic investigation were compared...
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The investigation of the effects of counterions in protein dynamics simulations
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Construction and purification of his6-Thermus thermophilus MutS protein
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Construction and purification of his6-Thermus thermophilus MutS protein.
PublikacjaGen mutS z termofilnej bakterii Thermus thermophilus zamplifikowano przy użyciu PCR, sklonowano i przeprowadzono jego ekspresję w E. coli. Rekombinantowe białko MutS zawierające oligohistydynową domenę na N-końcu oczyszczono w jednoetapowej procedurze przy wykorzystaniu chromatografii powinowactwaNi(2+). Zdolność do rozpoznania niekomplementarności białka his(6)-MutS potwierdzono w eksperymentach ochrony DNA przed trawieniem...
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MP3vec: A Reusable Machine-Constructed Feature Representation for Protein Sequences
Publikacja—Machine Learning (ML) methods have been used with varying degrees of success on protein prediction tasks, with two inherent limitations. First, prediction performance often depends upon the features extracted from the proteins. Second, experimental data may be insufficient to construct reliable ML models. Here we introduce MP3vec, a transferable representation for protein sequences that is designed to be used specifically for sequence-to-sequence...
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Cancer Familial Aggregation (CFA) and G446A polymorphism in ARLTS1 gene
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Aggregation of Rhodamine 6G in titanium dioxide nanolayers and bulk xerogels
PublikacjaNanolayers and bulk xerogels of Rhodamine 6G (Rh6G) in titanium dioxide (Rh6G/TiO2) were prepared using the sol–gel method. The spectroscopic and structural properties of these two types of hybrid matrices were studied as a function of dye concentration. In both cases absorption, fluorescence and time resolved emission spectra show the formation of fluorescent aggregates. The observed stronger changes in characteristics of bulk...