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Search results for: denaturation temperature
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Determination of denaturation temperature of connective tissue proteins by viscometric measurements.
Open Research DataViscometric denaturation temperature of connective tissue proteins was determined by measuring viscosity with a Brookfield viscometer, using a LV SC4 - 18, 25 or LV3 spindle and shear rates from 50 to 110 s-1 (Fig.1). Freeze-dried protein samples were dissolved in 0.5 M acetic acid at 4 °C and concentration of 20 mg/mL. The solution was stirred with...
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Monitoring of lysozyme thermal denaturation by volumetric measurements and nanoDSF technique in the presence of N-butylurea
PublicationThe results of thermal studies of denaturation of hen egg white lysozyme (HEWL) in water and an aqueous solution of N-butylurea (BU) are presented. High-precision densimetric measurements were used to characterize and analyze the changes of the specific volume, v, during temperature elevation. The temperature of the midpoint of protein denaturation was also determined by nanoDSF technique (differential scanning fluorimetry). The...
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Effect of osmolytes on the thermal stability of proteins: replica exchange simulations of Trp-cage in urea and betaine solutions
PublicationAlthough osmolytes are known to modulate the folding equilibrium, the molecular mechanism of their effect on thermal denaturation of proteins is still poorly understood. Here, we simulated the thermal denaturation of a small model protein (Trp-cage) in the presence of denaturing (urea) and stabilizing (betaine) osmolytes, using the all-atom replica exchange molecular dynamics simulations. We found that urea destabilizes Trp-cage...
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The effect of high pressure at subzero temperature on proteins solubility, drip loss and texture of fish (cod and salmon) and mammal’s (pork and beef) meat
PublicationOne of the possibilities of using high pressure technique in inactivation of microorganism is conducting this process at subzero temperature. However, for its practical application in meat preservation the appropriate properties of meat should be kept. Therefore, the aim of this work was to examine the effect of pressure at subzero temperature (without freezing of water) on proteins and texture of mammal’s and cold-adapted fish...
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Influence of temperature and interactions with ligands on dissociation of dsDNA and ligand-dsDNA complexes of various types of binding : an electrochemical study.
PublicationSeveral medicinally important compounds that bind to dsDNA strands via intercalation (C-1311, C-1305, EtBr), major groove binding (Hoechst 33258) and covalent binding (cis-Pt) were examined. The obtained results suggest that both the transfer of conformation B to C and the denaturation process, for the ligand-dsDNA complexes, except for covalently bound cis-Pt, took place at higher temperatures compared to the unbound helix. Furthermore,...
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Structural changes of a simple peptide—Trpzip-1—in aqueous solutions and the corresponding hydration phenomena under the influence of temperature
PublicationTrpzip-1, a simple β-hairpin, is a rare example of peptide with stable secondary structure and can be a convenient model to study temperature-related processes that potential prion or amyloid proteins undergo. Although its sequence is simple, the exact processes which the peptide undergoes in aqueous solutions are quite complex and not well understood. The selection of well-established experimental (DSC, FTIR) and theoretical methods...
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Isolation and some properties of collagen from the backbone of Baltic cod(Gadus morhua)
PublicationOssein from Baltic cod backbone was obtained after extraction of non-collagenous protein with 0.1 M NaOH solution and demineralization with 1.0 M HCl solution. The extractions were performed at 4 C for24, 48 and 72 h using a solid/solution ratio from 1:4 to 1:8 (w/v). After 48 h of extraction in 0.5 M acetic acid only about 25% of collagen was dissolved. After 48 h of extraction at optimal concentration of pepsin(4 mg/g ossein)...
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Isolation and characterization of Acid Soluble Collagen from the Skin of African Catfish (Clarias gariepinus), Salmon (Salmo salar) and Baltic cod (Gadus morhua)
PublicationAcid-soluble collagen (ASC) from the fish skin of African catfish (Clarias gariepinus), Salmon (Salmo salar) and Baltic cod (Gadus morhua) was extracted and characterized. The ASC extraction yield was 75%, 73% and 68%, respectively. The denaturation and melting temperatures of African catfish ASC (29.3°C and 100.0°C) were significantly higher than ASC of Salmon and Baltic cod (20.6°C and 90.5°C; 15.2°C and 86.7°C, respectively), assessed...
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Cloning, Expression and Purification of Wild-Type Trehalose Synthase from Deinococcus geothermalis
PublicationThe aim of this study was isolation and cloning of trehalose synthase gene derived from extremophilic microorganism to the expression vectors in the Tabor-Studier system and its expression in Rosetta(DE3)pLysS Escherichia coli cells. The second phase of the study consisted of proteins purification using an initial denaturation of host proteins and salting-out proteins by ammonium sulfate.
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Typing of Scopulariopsis and Microascus fungi by Random Amplified Polymorphic DNA (RAPD)
PublicationOBJECTIVES Scopulariopsis species and their teleomorphs of the genus Microascus are commonly isolated from soil, decaying plant material and indoor environments. Moreover, certain Scopulariopsis and Microascus species are recognised as opportunistic human pathogens. Although most species can be identified by detailed morphological study, phenotypic characters appear to overlap in several cases and morphology seems to be insufficient...
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Cyanogenic Compounds and Estrogen Disruptors
PublicationBalanced diet consists largely of plants containing cyanogenic compounds in the form of the more common cyanogenic glycosides and sometimes lipids. Maize, wheat, rye, apples, barley, oats, sugar cane and yet many other plants consumed by humans contain cyanogenic compounds. However the risk of poisoning is negligible as it is very easy to remove the toxic HCN by grinding and drying in air or soaking in water and an additional...
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A simple modification of PCR thermal profile applied to evade persisting contamination
PublicationThe polymerase chain reaction (PCR), one of the most commonly applied methods of diagnostics and molecular biology has a frustrating downside known as the false positive signal or contamination. Several solutions to avoid and to eliminate PCR contaminations have been worked out to date but the implementation of these solutions to laboratory practice may be laborious and time consuming. A simple approach to circumvent the problem...
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Marine polymers in tissue bioprinting: Current achievements and challenges
PublicationBioprinting has a critical role in tissue engineering, allowing the creation of sophisticated cellular scaffolds with high resolution, shape fidelity, and cell viability. Achieving these parameters remains a challenge, necessitating bioinks that are biocompatible, printable, and biodegradable. This review highlights the potential of marine-derived polymers and crosslinking techniques including mammalian collagen and gelatin along...
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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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The role of bile salts in digestion
PublicationBile salts (BS) are bio-surfactants present in the gastrointestinal tract (GIT) that play a crucial role in the digestion and absorption of nutrients. The importance of BS for controlled release and transport of lipid soluble nutrients and drugs has recently stimulated scientific interest in these physiological compounds. BS are so-called facial amphiphiles showing a molecular structure that is very distinct from classical surfactants....
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Molecular basis of the osmolyte effect on protein stability: a lesson from the mechanical unfolding of lysozyme
PublicationOsmolytes are a class of small organic molecules that shift the protein folding equilibrium. For this reason, they are accumulated by organisms under environmental stress, and find applications in biotechnology where proteins need to be stabilized or dissolved. However, despite years of research, debate continues over the exact mechanisms underpinning the stabilizing and denaturing effect of osmolytes. Here, we simulated the mechanical...
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Two bacterial small heat shock proteins, IbpA and IbpB, form a functional heterodimer
PublicationSmall 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...