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Search results for: denaturation of proteins
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Fibrillar aggregates in powdered milk
PublicationThis research paper addresses the hypothesis that powdered milk may contain amyloid fibrils. Amyloids are fibrillar aggregates of proteins. Up to this time, research on the presence of amyloids in food products are scarce. To check the hypothesis we performed thioflavin T fluorescence assay, X-ray powder diffraction, atomic force microscopy and fluorescence microscopy imaging. Our preliminary results show that commercially available...
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Induction of immune responses in sheep by vaccination with liposome-entrapped DNA complexes encoding Toxoplasma gondii MIC3 gene
PublicationToxoplasma gondii is a parasite that has been extensively studied due to its medical and veterinary importance in terminating pregnancies. Consequently, a satisfactory vaccine is required to control itsadverse effects on pregnant animals. The microneme protein, MIC3, is a major adhesion protein that binds to the surface of host cells and parasites, and is therefore a potential vaccine against T. gondii.The viability of MIC3 as...
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Amyloid fibril formation in the presence of water structure-affecting solutes
PublicationThe impact of the differently hydrated non-electrolytes (protein structure destabilizers) on the fibrillation of hen egg white lysozyme (HEWL) was investigated. Two isomeric urea derivatives i.e. butylurea (BU) and N,N,N′,N′-tetramethylurea (TMU) were chosen as a tested compounds. The obtained results show that butylurea exerts greater impact on HEWL and its fibrillation than tetramethylurea. Both substances decrease the time of...
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Establishing the allosteric mechanism in CRISPR‐Cas9
PublicationAllostery is a fundamental property of proteins, which regulates biochemical information transfer between spatially distant sites. Here, we report on the critical role of molecular dynamics (MD) simulations in discovering the mechanism of allosteric communication within CRISPR‐Cas9, a leading genome editing machinery with enormous promises for medicine and biotechnology. MD revealed how allostery intervenes during at least three...
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Pilicides effectively hinder chaperone-usher interactions in all Gram-negative bacteria
PublicationThe chaperone-usher pathway of adhesive structures biogenesis is highly conserved in all Gram-negative bacteria. Pili are polymers of thousands protein subunits that possess conserved immunoglobuline-like structure denoted by lack of the seventh G strand. The effect of this structural defect is a hydrophobic acceptor cleft. The folding of protein subunits is strictly dependent on the action of specific periplasmic chaperone protein...
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Atomic resolution crystal structure of HV-BBI protease inhibitor from amphibian skin in complex with bovine trypsin
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Common functionally important motions of the nucleotide‐binding domain of H sp70
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Fusion of DNA-binding domain of Pyrococcus furiosus ligase with TaqStoffel DNA polymerase as a useful tool in PCR with difficult targets
PublicationThe DNA coding sequence of TaqStoffel polymer- ase was fused with the DNA-binding domain of Pyrococcus furiosus ligase. The resulting novel recombinant gene was cloned and expressed in E. coli. The recombinant enzyme was purified and its enzymatic features were studied. The fusion protein (PfuDBDlig-TaqS) was found to have enhanced processivity as a result of the conversion of the Taq DNA polymerase from a relatively low processive...
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Immobilized biocatalysts - useful tool for industrial processes
PublicationThe main goal of biomaterials immobilization is the industrial re-use of them for many reaction cycles. However, application of this technolgoy for full commercialization requires more experiments in this field. In this study thermostable beta-galactosidases from Ptrococcus woesei and Meiothermus ruber were taken as model proteins immobilized in alginate gel.
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New recombinant chimeric antigens, P35-MAG1, MIC1-ROP1, and MAG1-ROP1, for the serodiagnosis of human toxoplasmosis
PublicationThe aim of the study was to evaluate the usefulness of 3 chimeric Toxoplasma gondii antigens, P35-MAG1,MIC1-ROP1 andMAG1-ROP1, in the serodiagnosis of an acute toxoplasmosis in humans. Proteins were produced as fusion proteins containing His tags ends and then further purified by metal affinity chromatography. Their application for the diagnosis of recently acquired T. gondii infection was tested in IgG and IgM enzyme-linked immunosorbent...
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Extracting functional groups of ALLINI to design derivatives of FDA‐approved drugs: Inhibition of HIV‐1 integrase
PublicationHIV‐1 integrase (IN) is crucial for integration of viral DNA into the host genome and a promising target in development of antiretroviral inhibitors. In this work, six new compounds were designed by linking the structures of two different class of HIV‐1 IN inhibitors (active site binders and allosteric IN inhibitors (ALLINIs)). Among newly designed compounds, INRAT10b was found most potent HIV‐1 IN inhibitor considering different...
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DNA-reactive anticancer imidazoacridinone C-1311 is a new inhibitor of hypoxia-inducible factor 1 alpha, vascular endothelial growth factor and tumor angiogenesis
PublicationHypoxia-inducible factor 1 (HIF-1) plays a critical role for tumor adaptation to hypoxia and promotes angiogenesis. Antitumor imidazoacridinone C-1311 is a DNA reactive topoisomerase II and FLT3 receptor tyrosine kinase inhibitor selected for phase II clinical trials for breast cancer. Here, we demonstrate the new mechanism of C-1311 action involving HIF-1a, vascular endothelial growth factor (VEGF) and angiogenesis as additional...
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Triazoloacridone C-1305 impairs XBP1 splicing by acting as a potential IRE1α endoribonuclease inhibitor
PublicationInositol requiring enzyme 1 alpha (IRE1α) is one of three signaling sensors in the unfolding protein response (UPR) that alleviates endoplasmic reticulum (ER) stress in cells and functions to promote cell survival. During conditions of irrevocable stress, proapoptotic gene expression is induced to promote cell death. One of the three signaling stressors, IRE1α is an serine/threonine-protein kinase/endoribonuclease (RNase) that...
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Functional properties of edible films for food applications - a review
PublicationApplication of natural polymers to forming edible films for food applications has been reviewed. Due to the hydrophilic nature of proteins and polysaccharides, films prepared from these polymers are too susceptible to moisture. Modification of them with critically selected a suitable compounds can result in their improved functional properties and making them useful for food packaging.
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Extracellular secretion of Pseudoalteromonas sp. cold-adapted esterase in Escherichia coli in the presence of Pseudoalteromonas sp. components of ABC transport system
PublicationEnzymy lipolityczne, głównie lipazy i esterazy, stanowią cenną grupę biokatalizatorów wykorzystywanych w przemyśle. Coraz większe zainteresowanie tą klasą enzymów sprawiło, że poszukuje się alternatywnych źródeł ich pozyskiwania. W celu zbadania wpływu białek transportu ABC Pseudoalteromonas sp. 643A na ekspresję genu, sekrecję i aktywność esterazy EstA z tego mikroorganizmu w systemie ekspresyjnym E. coli skonstruowano układ do...
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Therapy-Related Changes in the Serum Proteome Patterns of Early Stage Breast Cancer Patients with Different Outcomes
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Molecular Simulations of Rhodopsin Tetrameter
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Low-Molecular-Weight Aldehyde Inhibitors of Cathepsin G
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Pegylated Fluorescent Peptides as Substrates of Proteolytic Enzymes
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Designing of Substrates and Inhibitors of Bovine α-Chymotrypsin with Synthetic Phenylalanine Analogues in Position P1
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Novel method of expression and purification of hirudin based on pBAD TOPO, pTYB12 vectors and gene synthesis
PublicationW pracy przedstawiono nową, szybką i tanią metodę otrzymywania, ekspresji i oczyszczania białka hirudyny naturalnie izolowanego z ślinianek pijawki lekarskiej. Hirudyna pełni funkcje bezpośredniego inhibitora trombiny, głównego białka biorącego udział w tworzeniu skrzepów krwi. Właściwości te wykorzystywane są od wielu lat w klinice. Opracowana metoda pozwoliła uzyskać 17 mg/l hodowli E. coli białka o wysokiej czystości i aktywności...
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Synthesis and SAR Studies of Antibacterial Peptidyl Derivatives Based upon the Binding Site of Human Cystatin C
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Analogues of Trypsin Inhibitor SFTI-1 with Disulfide Bridge Substituted by Various Length of Carbonyl Bridges
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Molecular Modeling of the Neurohypophyseal Receptor/Atosiban Complexes
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Molecular Dynamics Study of the Internal Water Molecules in Vasopressin and Oxytocin Receptors
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Isolation of the GFA1 gene encoding glucosamine-6-phosphate synthase of Sporothrix schenckii and its expression in Saccharomyces cerevisiae
PublicationGlucosamine-6-phosphate synthase (GlcN-6-P synthase) is an essential enzyme involved in cell wall biogenesis that has been proposed as a strategic target for antifungal chemotherapy. Here we describe the cloning and functional characterization of Sporothrix schenckii GFA1 gene which was isolated from a genomic library of the fungus. The gene encodes a predicted protein of 708 amino acids that is homologous to GlcN-6-P synthases...
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New conjugates of tuftsin and muramyl dipeptide as stimulators of human monocytes-derived dendritic cells
PublicationMuramyl dipeptide (MDP) and tuftsin are known biologically active compound displaying a significant influence on various cell populations of innate immune response. MDP, as a fragment of bacterial cell wall, stimulates not only macrophages and monocytes, but also dendritic cells. In contrast, little is known about tuftsin influence on these cells. Therefore it seemed vital to access whether tuftsin or its derivatives conjugated...
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High yield expression and single step purification of Toxoplasma gondii SAG1, GRA1, GRA7 antigens in Escherichia coli.
PublicationPraca przedstawia metodę uzyskiwania antygenów rekombinowanych Toxoplasmagondii o wysokiej czystości, które można zastosować w immunodiagnostyce. Antygeny T. gondii eksprymowane w komórkach E. coli zawierały polihistydynowedomeny fuzyjne na końcu N i C białka. Pozwalało to na jednoetapowe oczyszczanie białek metodą chromatografii metalopowinowactwa na złożu Ni2+ -IDA-Sepharose. Immunoreaktywność antygenów rekombinowanych...
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High level expression, secretion and purification of the termostable aqualysin I from Thermus aquaticus YT-1 in Pichia pastoris.
PublicationOtrzymano aktywną proteazę serynową Thermus aquaticus z systemu nadprodukcji Escherichia coli. Oczyszczono enzym przy zastosowaniu chromatografii metalo-powinowactwa.
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A two-plasmid Escherichia coli system for expression of Dr adhesins
PublicationPraca opisuje konstrukcję wydajnego systemu produkcji fimbrii Dr. System składa się z dwóch plazmidów. Plazmid pACYCpBAD-DraC-C-His zawiera pod kontrolą promotora arabinozowego gen draC kodujący białko kanałotwórcze DraC. Plazmid pET-30b-sygDraBE zawiera pod kontrolą promotora T7lac geny draB i draE kodujące odpowiednio białko opiekuńcze DraB oraz adhezynę DraE. Oba plzamidy posiadają różne ori replikacji co pozwala na ich jednoczesne...
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Characterization of recombinant homocitrate synthase from Candida albicans
PublicationLYS21 and LYS22 genes from Candida albicans encoding isoforms of homocitrate synthase (HCS), an enzyme catalyzing the first committed step in the L-lysine biosynthetic pathway, were cloned and expressed as NoligoHistagged fusion proteins in Escherichia coli. The purified gene products revealed HCS activity, i.e. catalyzed the condensation of α-ketoglutarate with acetyl-coenzyme A to yield homocitrate. The recombinant enzymes were purified...
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Introduction of Pro and Its Analogues in the Conserved P1 Position of Trypsin Inhibitor SFTI-1 Retains Its Inhibitory Activity
PublicationA number of monocyclic SFTI-1 analogues modified in the conserved inhibitor P1 position by Pro, its L-hydroxyproline (Hyp) derivative as well as mimetics with different ring size were synthesized by the solid-phase method. Replacement of Ser6 by Pro, Hyp, and a four-member ring, L-azetidine-2-carboxylic acid (Aze), retained trypsin or chymotrypsin inhibitory activity. The determined association equilibrium constants of these analogues...
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Construction, purification, and functional characterization of His-tagged Candida albicans glucosamine-6-phosphate synthase expressed in Escherichia coli
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Purification to Homogeneity of Candida albicans Glucosamine-6-phosphate Synthase Overexpressed in Escherichia coli
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Scarabaeidae as human food – A comprehensive review
PublicationRising global population and sustainable protein demand have sparked interest in unique food sources. Entomophagy, or insect consumption, presents a solution and Scarab beetles, part of the Scarabaeidae family, offer a novel food option. The comprehensive review underscores their potential as human food, with strong nutrition, low environmental impact, and the ability to ease strain on conventional agriculture. Nutritional analysis...
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B-GALACTOSIDASE ARTHROBACTER SP. 32cB - OBTAINING THE GENE SEQUENCE, CONSTRUCTION OF THE EXPRESSION SYSTEM, BIOSYNTHESIS AND BIOCHEMICAL CHARACTERIZATION OF THE ENZYME
PublicationINTRODUCTION: β-Galactosidase is an enzyme which catalyzes the hydrolysis of O glycosidic bond in β-galactosides. Another activity of β galactosidase is a transglycosylation activity. The main industrial use of this protein is the hydrolysis of lactose in milk in a cooling conditions. Synthesis of galactooligosaccharides, which are mostly used as a prebiotics added to some foods or available as dietary supplements, is only one...
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Nanomaterials for photothermal and photodynamic cancer therapy
PublicationIn recent years, the role of optically sensitive nanomaterials has become powerful moieties in therapeutic techniques and has become particularly emphasized. Currently, by the extraordinary development of nanomaterials in different fields of medicine, they have found new applications. Phototherapy modalities, such as photothermal therapy (PTT) by toxic heat generation and photodynamic therapy (PDT) by reactive oxygen species, are...
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Recombinant !ermostable AP Exonuclease from Thermoanaerobacter tengcongensis: Cloning, Expression, Purification, Properties and PCR Application
PublicationApurinic/apyrimidinic (AP) sites in DNA are considered to be highly mutagenic and must be corrected to preserve genetic integrity, especially at high temperatures. !e gene encoding a homologue of AP exonuclease was cloned from the thermophilic anaerobic bacterium Thermoanaerobacter tengcongensis and transformed into Escherichia coli. The protein product showed high identity (80%) to human Ape1 nuclease, whereas to E. coli exonuclease...
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Interactions in aqueous solutions of K-peptide and DMSO – spectroscopic and calorimetric studies
PublicationIntroduction K-peptide (GILQINSRW) – short 9 amino acid fragment of the hen egg white lysozyme has the ability to form amyloid structures. Dimethyl sulfoxide (DMSO) is an osmolyte which can alter this ability. Our goal was to get an insight into the mechanism of Kpeptide-DMSO interactions in aqueous solutions. Such a knowledge can be helpful to understand processes leading to various neurodegenerative diseases. Methods ATR-FTIR...
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Genetic and Epigenetic Aspects of Atopic Dermatitis
PublicationAtopic dermatitis is a heterogeneous disease, in which the pathogenesis is associated with mutations in genes encoding epidermal structural proteins, barrier enzymes, and their inhibitors; the role of genes regulating innate and adaptive immune responses and environmental factors inducing the disease is also noted. Recent studies point to the key role of epigenetic changes in the development of the disease. Epigenetic modifications...
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Properties of Different Varieties of Durian
PublicationDurian (Durio zibethinus Murr.), like many other exotic, tropical, and conventional fruits, is important in the prevention of different diseases. In this study, the characterization of the main bioactive compounds of the most popular cultivars of durian and their properties are described. The changes in the quality indices of the antioxidant status were determined by CUPRAC, ABTS, FRAP, DPPH, and ORAC assays. The profiling of phytochemicals...
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Molecular Targets for Anticandidal Chemotherapy
PublicationA relatively small number of anticandidal chemotherapeutics used in clinical practice is at least in part consequence of a limited number of their molecular targets: ergosterol in the membrane, lanosterol demethylase, b(1!3) glucan synthase, and DNA/RNA biosynthesis. Much more potential novel targets have been revealed by the comparative genomic studies identifying essential genes unique for Candida albicans or resulted from recognition...
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Preparation and characterization of porous scaffolds from chitosan-collagen-gelatin composite
PublicationNovel porous scaffolds composed of chitosan, collagen and gelatin were prepared and characterized. For preparing scaffolds gelatin and collagen isolated from fish skins with various physicochemical properties were used. In order to reduce preparation solubility glutaraldehyde in the amount of 1%, w/w relative to the total biopolymers weight in solution was used. All obtained biomaterials showed a homogeneous porosity. Protein polymer...
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Hopf bifurcation in time‐delayed gene expression model with dimers
PublicationWe study a mathematical model of gene transcription and protein synthesis with negative feedback. We consider a system of equations taking into account the formation of dimers (i.e., complex formed by two protein monomers), the way in which dimers bind to DNA and time delay in translation process. For the model consisting of three ordinary differential equations with time delay, we derive conditions for stability of the positive...
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Microencapsulation of fish oil – determination of optimal wall material and encapsulation methodology
PublicationFor the first time, we present a meta-analysis of experimental and literature data to determine which microencapsulation methodology, and which wall material are best suited to protect fish oil. Our analysis covered a period of several decades of research (1984–2018). The analysis was conducted on 196 literature data-points, and 16 data-points determined experimentally for this publication. PLS regression was used to determine...
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Effect of conventional cooking on changes in the contents of basic composition and glucosinolates in kale
PublicationBrassica vegetables have been strongly recommended as part of human diet because of its high content of bioactive sulphur compounds, eg glucosinolates. The nutrient and health promoting compounds in kale are significantly affected by traditional cooking. The study investigated changes in the levels of dry mass, ash, fat, total protein, dietary fibre as well as total and individual glucosinolates in the kale due to the traditional...
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Which casein in sodium caseinate is most resistant to in vitro digestion? Effect of emulsification and enzymatic structuring
PublicationWe investigated the resistance of individual constituent casein epitopes (αS1-, αS2-, β- and κ-CN) in food-grademilk protein sodium caseinate (NaCN) to simulated human gastro-duodenal digestion. The influence of NaCNadsorption to the surface of oil-in-water emulsion droplets and the effect of crosslinking of the protein withenzyme transglutaminase (TG) on the proteolysis were studied by indirect ELISA. TG crosslinking renderedfragments...
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Example of utilization of permeabilized microbial cells
PublicationThe benefits of using whole bacterial cells not only exclude expensive, laborious protein isolation and purification but also stabilize enzymes by cytosol components. Increase in activity of the cells can be achieved by cells permeabilization.
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Actions of a nitric oxide donor on prostaglandin production and angiogenic activity in the equine endometrium
PublicationNitric oxide (NO) plays an important role in prostaglandin secretion and angiogenesis in the reproductive system. In the present study, the roles of the NO donor spermine NONOate and tumour necrosis factor-alpha (TNF; as a positive control) in prostaglandin production and angiogenic activity of equine endometria during the oestrous cycle were evaluated. In addition, the correlation between NO production...
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Characterization of two aminotransferases from Candida albicans
PublicationAminoadipate aminotransferase (AmAA) is an enzyme of α-aminoadipate pathway (AAP) for l-lysine biosynthesis. AmAA may also participated in biosynthesis or degradation of aromatic amino acids and in d-tryptophan based pigment production. The AAP is unique for fungal microorganisms. Enzymes involved in this pathway have specific structures and properties. These features can be used as potential molecular markers. Enzymes catalyzing...