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Soins; La Revue de Reference Infirmiere Apr 2017Fast, effective and pain-free cleansing is essential in the management of wounds, in order to favour the formation of the granulation tissue and the filling of the... (Review)
Review
Fast, effective and pain-free cleansing is essential in the management of wounds, in order to favour the formation of the granulation tissue and the filling of the cavity. Faced with a chronic wound which was not progressing from the inflammatory phase, caregivers put in place a technique combining negative pressure therapy and instillations of sodium bicarbonate and oxygenated water. The initial results are promising, with the patient benefiting from effective and pain-free cleansing.
Topics: Debridement; Detergents; Humans; Negative-Pressure Wound Therapy; Pressure Ulcer; Sodium Chloride; Wound Healing; Wound Infection; Wounds and Injuries
PubMed: 28411655
DOI: 10.1016/j.soin.2017.02.018 -
Environmental Science and Pollution... Mar 2023At household level, clothes washing has been recognised as an emitter of microplastics (MPs) into the environment and it is supposed that dishwashing is also a source of...
At household level, clothes washing has been recognised as an emitter of microplastics (MPs) into the environment and it is supposed that dishwashing is also a source of MPs, although little attention has been paid so far. In this work, the emission of MPs released from dishwashing procedures at household level has been studied. The effect of different parameters such as time, temperature and type of detergent has been analysed. In addition, the MP content of tap water has been evaluated in order to determine its contribution to the MPs in dishwasher effluent. Results showed that when the dishwasher was operated empty with a pre-wash programme (15 min and room water temperature), between 207 and 427 MPs were released per load (3 L), whereas this value increased notably with an intensive programme (164 min and water at 70 °C) (1025-1370 MPs per load, 15 L), which highlighted the effect of temperature and time on MP release. Additionally, when a polypropylene lunch box was washed, the number of MPs released increased by 14 ± 3 MPs and 166 ± 12 MPs of total. Finally, the influence of the use of detergent with the dishwasher empty and containing lunch boxes has been studied. With detergent, 35-54% more MPs were released from dishwasher accessories, whereas no additional release took place from lunch boxes. This work shows for the first time the important contribution of domestic dishwashing to MP pollution and the environmental benefits of using more environmentally friendly materials in both dishwashing machine accessories and food utensils.
Topics: Microplastics; Plastics; Detergents; Environmental Monitoring; Water Pollutants, Chemical
PubMed: 36701065
DOI: 10.1007/s11356-023-25433-7 -
Soft Matter Jun 2020Many highly ordered complex systems form by the spontaneous self-assembly of simpler subunits. An important biophysical tool that relies on self-assembly is the Nanodisc...
Many highly ordered complex systems form by the spontaneous self-assembly of simpler subunits. An important biophysical tool that relies on self-assembly is the Nanodisc system, which finds extensive use as native-like environments for studying membrane proteins. Nanodiscs are self-assembled from detergent-solubilized mixtures of phospholipids and engineered helical proteins called membrane scaffold proteins (MSPs). Detergent removal results in the formation of nanoscale bilayers stabilized by two MSP "belts." Despite their numerous applications in biology, and contributions from many laboratories world-wide, little is known about the self-assembly process such as when the bilayer forms or when the MSP associates with lipids. We use fluorescence and optical spectroscopy to probe self-assembly at various equilibria defined by the detergent concentration. We show that the bilayer begins forming below the critical micellar concentration of the detergent (10 mM), and the association of MSP and lipids begins at lower detergent levels, showing a dependence on the concentrations of MSP and lipids. Following the dissolution process by adding detergent to purified Nanodiscs demonstrates that the self-assembly is reversible. Our data demonstrate that Nanodisc self-assembly is experimentally accessible, and that controlling the detergent concentration allows exquisite control over the self-assembly reaction. This improved understanding of self-assembly could lead to better functional incorporation of hitherto intractable membrane target proteins.
Topics: 2-Naphthylamine; Anisotropy; Detergents; Fluorescent Dyes; Laurates; Lipid Bilayers; Membrane Proteins; Nanostructures; Phospholipids; Sodium Cholate; Spectrum Analysis; Thermodynamics; Tyrosine
PubMed: 32524103
DOI: 10.1039/d0sm00336k -
Current Protocols in Protein Science Aug 2014Well-characterized membrane protein detergent complexes (PDC) that are pure, homogenous, and stable, with minimized excess detergent micelles, are essential for... (Review)
Review
Well-characterized membrane protein detergent complexes (PDC) that are pure, homogenous, and stable, with minimized excess detergent micelles, are essential for functional assays and crystallization studies. Procedural steps to measure the mass, size, shape, homogeneity, and molecular composition of PDCs and their host detergent micelles using size-exclusion chromatography (SEC) with a Viscotek Tetra Detector Array (TDA; absorbance, refractive index, light scattering, and viscosity detectors) are presented in this unit. The value of starting with a quality PDC sample, the precision and accuracy of the results, and the use of a digital benchtop refractometer are emphasized. An alternate and simplified purification and characterization approach using SEC with dual absorbance and refractive index detectors to optimize detergent and lipid concentration while measuring the PDC homogeneity is also described. Applications relative to purification and characterization goals are illustrated as well.
Topics: Chromatography, Gel; Detergents; Membrane Proteins; Micelles; Refractometry
PubMed: 25081744
DOI: 10.1002/0471140864.ps2910s77 -
Biochimica Et Biophysica Acta.... Mar 2023The exceptional capacities of aquaporins in terms of water permeation and selectivity have made them an interesting system for membrane applications. Despite the...
BACKGROUND
The exceptional capacities of aquaporins in terms of water permeation and selectivity have made them an interesting system for membrane applications. Despite the multiple attempts for immobilizing the aquaporins over a porous substrate, there is a lack of studies related to the purification and reconstitution steps, principally associated with the use of detergents in solubilization and destabilization steps. This study analyzed the effect of detergents in Aquaporin Z solubilization, considering the purity and structural homogeneity of the protein.
METHODS
The extraction process was optimized by the addition of detergent at the sonication step, which enabled the omission of the ultracentrifugation and resuspension steps. Two detergents, Triton X-100, and octyl-glucoside were also evaluated. Destabilization mediated by detergents was used as reconstitution method. Saturation and solubilization points were defined by detergent concentration and both, liposomes and proteoliposomes, were analyzed by size distribution and permeability assays. Detergent removal with Bio-beads was also analyzed.
RESULTS
Octyl glucoside ensures structural stability and homogeneity of Aquaporin Z. However, high concentrations of detergents induce the presence of defects in proteoliposomes. While saturated liposomes create homogeneous and functional structures, solubilized liposomes get affected by a reassembly process, creating vesicle defects with anomalous permeability profiles.
CONCLUSIONS
Detergent concentration affects the structural conformation of proteoliposomes in the reconstitution process.
GENERAL SIGNIFICANCE
Since the destabilization process is dependent on vesicle, detergent, and buffer composition, optimization of this process should be mandatory for further studies. All these considerations will allow achieving the potential of Aquaporins and any other integral membrane protein in their applications for industrial purposes.
Topics: Detergents; Liposomes; Membrane Proteins; Octoxynol; Aquaporins
PubMed: 36535340
DOI: 10.1016/j.bbamem.2022.184101 -
The Journal of Physical Chemistry. B Nov 2017Although fundamentally significant in structural, chemical, and membrane biology, the interfacial protein-detergent complex (PDC) interactions have been modestly...
Although fundamentally significant in structural, chemical, and membrane biology, the interfacial protein-detergent complex (PDC) interactions have been modestly examined because of the complicated behavior of both detergents and membrane proteins in aqueous phase. Membrane proteins are prone to unproductive aggregation resulting from poor detergent solvation, but the participating forces in this phenomenon remain ambiguous. Here, we show that using rational membrane protein design, targeted chemical modification, and steady-state fluorescence polarization spectroscopy, the detergent desolvation of membrane proteins can be quantitatively evaluated. We demonstrate that depleting the detergent in the sample well produced a two-state transition of membrane proteins between a fully detergent-solvated state and a detergent-desolvated state, the nature of which depended on the interfacial PDC interactions. Using a panel of six membrane proteins of varying hydrophobic topography, structural fingerprint, and charge distribution on the solvent-accessible surface, we provide direct experimental evidence for the contributions of the electrostatic and hydrophobic interactions to the protein solvation properties. Moreover, all-atom molecular dynamics simulations report the major contribution of the hydrophobic forces exerted at the PDC interface. This semiquantitative approach might be extended in the future to include studies of the interfacial PDC interactions of other challenging membrane protein systems of unknown structure. This would have practical importance in protein extraction, solubilization, stabilization, and crystallization.
Topics: Detergents; Fluorescence Polarization; Hydrophobic and Hydrophilic Interactions; Membrane Proteins; Molecular Dynamics Simulation
PubMed: 29035562
DOI: 10.1021/acs.jpcb.7b08045 -
International Journal of Molecular... Mar 2023Proteases are important enzymes that are engaged in a variety of essential physiological functions and have a significant possible use in industrial applications. In...
Proteases are important enzymes that are engaged in a variety of essential physiological functions and have a significant possible use in industrial applications. In this work, we reported the purification and biochemical characterization of a detergent stable, antimicrobial, and antibiofilm potential protease (SH21) produced by CSB55 isolated from Korean fermented vegetable kimchi. SH21 was purified to obtain homogeneity via ammonium sulfate precipitation (40-80%), Sepharose CL-6B, and Sephadex G-75 column. By analyzing the SDS-PAGE and zymogram, it was determined that the molecular weight was around 25 kDa. The enzyme activity was almost completely inhibited in the presence of PMSF and DFP, which indicated that it was a member of the serine protease family. SH21 showed excellent activity with a broad range of pH and temperature, with its maximum pH of 9.0 and temperature of 55 °C. The enzyme had estimated K and V values of 0.197 mg/mL and 1.22 × 10 U/mg, respectively. In addition, it preserved good activity in the presence of different organic solvents, surfactants, and other reagents. This enzyme showed good antimicrobial activity that was evaluated by MIC against several pathogenic bacteria. Furthermore, it exhibited strong antibiofilm activity as determined by MBIC and MBEC assay and degraded the biofilms, which were analyzed by confocal microscopic study. These properties established that SH21 is a potent alkaline protease that can be used in industrial and therapeutic applications.
Topics: Detergents; Endopeptidases; Bacillus; Serine Proteases; Temperature; Bacterial Proteins; Anti-Infective Agents; Hydrogen-Ion Concentration; Enzyme Stability
PubMed: 36982846
DOI: 10.3390/ijms24065774 -
Biochemical Society Transactions Oct 2014Lysosomes are acidic organelles essential for degradation, signalling and cell homoeostasis. In addition, they play a key role in cell death. Permeabilization of the... (Review)
Review
Lysosomes are acidic organelles essential for degradation, signalling and cell homoeostasis. In addition, they play a key role in cell death. Permeabilization of the lysosomal membrane and release of hydrolytic enzymes to the cytosol accompanies apoptosis signalling in several systems. The regulatory mechanism of lysosomal stability is, however, poorly understood. Lipophilic or amphiphilic compounds with a basic moiety will become protonated and trapped within lysosomes, and such lysosomotropic behaviour is also found in many pharmacological drugs. The natural sphingolipid sphingosine exhibits lysosomotropic detergent ability and is an endogenous candidate for controlling lysosomal membrane permeabilization. The lysosomotropic properties of certain detergents might be of use in lysosome-targeting anticancer drugs and drug delivery system in the future. The present review summarizes the current knowledge on the targeting and permeabilizing properties of lysosomotropic detergents from a cellular and physicochemical perspective.
Topics: Animals; Antineoplastic Agents; Apoptosis; Chemical Phenomena; Detergents; Drug Delivery Systems; Humans; Intracellular Membranes; Lipid Bilayers; Lysosomes; Membrane Transport Modulators; Permeability; Sphingosine
PubMed: 25233432
DOI: 10.1042/BST20140145 -
Journal of Animal Science Jan 2023Two experiments were conducted to determine the digestible energy and metabolizable energy contents, as well as the apparent ileal digestibility and standardized ileal...
Two experiments were conducted to determine the digestible energy and metabolizable energy contents, as well as the apparent ileal digestibility and standardized ileal digestibility of amino acids in full-fat soybean fed to growing pigs. Ten full-fat soybean samples were collected from different areas in China and used in two experiments in this study. In Exp. 1, 66 growing pigs (initial body weight = 18.48 ± 1.2 kg) were randomly allotted to 1 of 11 diets (n = 6) including a corn basal diet and 10 experimental diets formulated by replacing the corn with 30% full-fat soybean. In Exp. 2, 11 growing pigs (initial body weight = 50.45 ± 3.2 kg) were surgically equipped with a T-cannula in the distal ileum and arranged in a 6 × 11 Youden square design with 11 diets and 6 periods. The diets included an N-free diet based on cornstarch and sucrose and 10 experimental diets formulated with full-fat soybeans as the sole source of amino acids. Chromic oxide was added into the diets as an indigestible maker to calculate the digestibility of the amino acids. Results showed that there was considerable variation in neutral detergent fiber, acid detergent fiber, and trypsin inhibitor contents in the 10 full-fat soybean samples with a coefficient of variation greater than 10%. On a dry matter basis, the averaged digestible energy and metabolizable energy values in the 10 full-fat soybean samples were 4,855 and 4,555 kcal/kg, respectively, both were positively correlated with the ether extract content. The best-fitted prediction equations for digestible energy and metabolizable energy of full-fat soybean were: digestible energy, kcal/kg = 3,472 + 94.87 × ether extract - 97.63 × ash (R2 = 0.91); metabolizable energy, kcal/kg = 3,443 + 65.11 × ether extract - 36.84 × trypsin inhibitor (R2 = 0.91). In addition, all full-fat soybean samples showed high apparent ileal digestibility and standardized ileal digestibility values in amino acids and were all within the range of previously published values. Those values significantly varied among different samples (P < 0.05) for most amino acids, except for glycine and proline. In conclusion, full-fat soybean is a high-quality protein ingredient with high ileal digestibility of amino acids when fed to growing pigs, and the metabolizable energy value of full-fat soybean could be predicted based on its ether extract and trypsin inhibitor contents.
Topics: Swine; Animals; Glycine max; Amino Acids; Digestion; Detergents; Trypsin Inhibitors; Animal Feed; Diet; Ileum; Ethers; Plant Extracts; Animal Nutritional Physiological Phenomena; Zea mays
PubMed: 36444860
DOI: 10.1093/jas/skac395 -
Methods (San Diego, Calif.) Sep 2018Integral membrane proteins are among the most fascinating and important biomolecules as they play a vital role in many biological functions. Knowledge of their atomic... (Review)
Review
Integral membrane proteins are among the most fascinating and important biomolecules as they play a vital role in many biological functions. Knowledge of their atomic structures is fundamental to the understanding of their biochemical function and key in many drug discovery programs. However, over the years, structure determination of integral membrane proteins has proven to be far from trivial, hence they are underrepresented in the protein data bank. Low expression levels, insolubility and instability are just a few of the many hurdles one faces when studying these proteins. X-ray crystallography has been the most used method to determine atomic structures of membrane proteins. However, the production of high quality membrane protein crystals is always very challenging, often seen more as art than a rational experiment. Here we review valuable approaches, methods and techniques to successful membrane protein crystallisation.
Topics: Chromatography, Gel; Crystallization; Crystallography; Detergents; Dynamic Light Scattering; Membrane Proteins; Micelles
PubMed: 29778646
DOI: 10.1016/j.ymeth.2018.05.014