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Biochimie May 2024Labelling of bacterial membranes using exogenous fatty acids has proven to be a valuable tool to investigate molecular interactions by in-cell solid-state nuclear...
Labelling of bacterial membranes using exogenous fatty acids has proven to be a valuable tool to investigate molecular interactions by in-cell solid-state nuclear magnetic resonance (ssNMR) spectroscopy, notably with antimicrobial peptides. However, the mechanism by which this labelling takes place in non-mutated bacteria has not yet been investigated. In this work, we propose a rapid method to assess the fate of the fatty acids during the labelling of bacteria, involving two different methylation schemes and gas chromatography coupled to mass spectrometry. We applied this approach to Gram(+) and Gram(-) bacteria grown with deuterated palmitic acid under different conditions. We assessed the extent of labelling, then the resulting membrane rigidity by H ssNMR. Our results reveal that the labelling mechanism depends on the detergent used to micellize the fatty acids. This labelling can be either active or passive, whether the fatty acids are metabolized and used in the phospholipids biosynthesis, or remain unmodified in the membrane. We discuss the best labelling protocol for studying peptide-membrane interactions.
PubMed: 38825063
DOI: 10.1016/j.biochi.2024.05.024 -
Scientific Reports May 2024In flaviviruses such as Dengue or Zika, non-structural (NS) NS4A protein forms homo-oligomers, participates in membrane remodelling and is critical for virulence. In...
In flaviviruses such as Dengue or Zika, non-structural (NS) NS4A protein forms homo-oligomers, participates in membrane remodelling and is critical for virulence. In both viruses, mature NS4A has the same length and three predicted hydrophobic domains. The oligomers formed by Dengue NS4A are reported to be small (n = 2, 3), based on denaturing SDS gels, but no high-resolution structure of a flavivirus NS4A protein is available, and the size of the oligomer in lipid membranes is not known. Herein we show that crosslinking Zika NS4A protein in lipid membranes results in oligomers at least up to hexamers. Further, sedimentation velocity shows that NS4A in mild detergent C14-betaine appears to be in fast equilibrium between at least two species, where one is smaller, and the other larger, than a trimer or a tetramer. Consistently, sedimentation equilibrium data was best fitted to a model involving an equilibrium between dimers (n = 2) and hexamers (n = 6). Overall, the large, at least hexameric, oligomers obtained herein in liposomes and in mild detergent are more likely to represent the forms of NS4A present in cell membranes.
Topics: Liposomes; Viral Nonstructural Proteins; Detergents; Zika Virus; Protein Multimerization
PubMed: 38822066
DOI: 10.1038/s41598-024-63407-y -
The Science of the Total Environment Aug 2024Wastewater-Based Epidemiology (WBE) is widely used to monitor the progression of SARS-CoV-2 pandemic. While there is a clear correlation between the number of COVID...
The different adsorption-degradation behaviors of SARS-CoV-2 by bioactive chemicals in wastewater: The suppression kinetics and their implications for wastewater-based epidemiology.
Wastewater-Based Epidemiology (WBE) is widely used to monitor the progression of SARS-CoV-2 pandemic. While there is a clear correlation between the number of COVID patients in a sewershed and the viral load in the wastewater, there is notable variability across different treatment plants. In particular, some facilities consistently exhibit higher viral content per diagnosed patient, implying a potential underestimation of the number of COVID patients, while others show a low viral load per diagnosed case, indicating potential attenuation of genetic material from the sewershed. In this study, we investigated the impact of nonylphenol ethoxylate (NPHE), linear alkylbenzene sulfonic acid (LABS), bisoctyl dimethyl ammonium chloride (BDAC), and didecyldimethylammonium chloride (DDAC), the surfactants that have been commonly used as detergents, emulsifiers, wetting agents on the stability of SARS-CoV-2 in wastewater. The results showed multiple and dynamic mechanisms, including degradation and desorption, can occur simultaneously during the interaction between SARS-CoV-2 and different chemicals depending on the physicochemical properties of each chemical. Through the elucidation of the dynamic interactions, the findings from this study could help the state health organizations and scientific community to optimize the SARS-CoV-2 wastewater-based epidemiology strategies.
Topics: Wastewater; SARS-CoV-2; COVID-19; Adsorption; Surface-Active Agents; Pandemics; Kinetics; Humans; Waste Disposal, Fluid; Wastewater-Based Epidemiological Monitoring; Water Pollutants, Chemical; Alkanesulfonic Acids
PubMed: 38815826
DOI: 10.1016/j.scitotenv.2024.173609 -
Biophysical Chemistry Aug 2024Reverse micelles (RMs) are spontaneously organizing nanobubbles composed of an organic solvent, surfactants, and an aqueous phase that can encapsulate biological...
Reverse micelles (RMs) are spontaneously organizing nanobubbles composed of an organic solvent, surfactants, and an aqueous phase that can encapsulate biological macromolecules for various biophysical studies. Unlike other RM systems, the 1-decanoyl-rac-glycerol (10MAG) and lauryldimethylamine-N-oxide (LDAO) surfactant system has proven to house proteins with higher stability than other RM mixtures with little sensitivity to the water loading (W, defined by the ratio of water to surfactant). We investigated this unique property by encapsulating three model proteins - cytochrome c, myoglobin, and flavodoxin - in 10MAG/LDAO RMs and applying a variety of experimental methods to characterize this system's behavior. We found that this surfactant system differs greatly from the traditional, spherical, monodisperse RM population model. 10MAG/LDAO RMs were discovered to be oblate ellipsoids at all conditions, and as W was increased, surfactants redistributed to form a greater number of increasingly spherical ellipsoidal particles with pools of more bulk-like water. Proteins distinctively influence the thermodynamics of the mixture, encapsulating at their optimal RM size and driving protein-free RM sizes to scale accordingly. These findings inform the future development of similarly malleable encapsulation systems and build a foundation for application of 10MAG/LDAO RMs to analyze biological and chemical processes under nanoscale confinement.
Topics: Micelles; Myoglobin; Surface-Active Agents; Glycerol; Cytochromes c; Flavodoxin; Laurates; Thermodynamics; Water; Dimethylamines
PubMed: 38815545
DOI: 10.1016/j.bpc.2024.107269 -
Turkish Journal of Medical Sciences 2023Surfactant is a surface-active substance that, in addition to its detergent effect, also has effects that reduce inflammation and fibrosis. Because of these effects, it...
BACKGROUND/AIM
Surfactant is a surface-active substance that, in addition to its detergent effect, also has effects that reduce inflammation and fibrosis. Because of these effects, it was aimed herein to investigate the effect of intraperitoneal surfactant application on preventing postoperative peritoneal adhesion formation in a uterine horn adhesion model.
MATERIALS AND METHODS
Twenty-one Wistar albino rats were randomly divided into 3 groups (G1-G3), as follows: G1 (n = 7): control group. The abdomen was opened and then closed; G2 (n = 7): adhesion group. The abdomen was opened. Then, a 2-cm linear incision was made over the right uterine horn, 2 mL of isotonic saline was administered intraperitoneally, and the abdomen was closed; and G3 (n = 7): treatment group. The abdomen was opened, a 2-cm linear incision was made over the right uterine horn, 2 mL (70 mg/kg) of surfactant was administered intraperitoneally, and the abdomen was closed. After 15 days, the rats were euthanized, the abdomens were reopened, and adhesion scoring was performed. After the right uterine horns were removed and fixed with 10% formalin, appropriate sections were taken from the traumatized tissue, stained with Masson's trichrome, and fibrosis and inflammation scoring were performed.
RESULTS
The adhesion area and intensity were significantly higher in G2 than in G1 and G3 (p = 0.001) and were similar in G1 and G3 (p = 0.165). While fibrosis and inflammation were significantly higher in G2 than in G1 and G3 (p = 0.001), there was no difference between G1 and G3 (p = 0.5).
CONCLUSION
Intraperitoneal surfactant administration at a dose of 70 mg/kg was found to be effective in preventing intraabdominal adhesion formation in a rat uterine horn model.
Topics: Animals; Tissue Adhesions; Rats, Wistar; Female; Surface-Active Agents; Rats; Postoperative Complications; Injections, Intraperitoneal; Uterus; Disease Models, Animal
PubMed: 38813488
DOI: 10.55730/1300-0144.5752 -
Heliyon May 2024Oat is a dual-purpose crop used for both food and feed for animals. The objective of this work is to characterize oat varieties for their genetic diversity in yield,...
Oat is a dual-purpose crop used for both food and feed for animals. The objective of this work is to characterize oat varieties for their genetic diversity in yield, physical traits, and nutritional composition, aiming to identify potential parent varieties for breeding programs to develop new oat varieties for improved livestock feed and diverse industrial applications. To conduct, chemical analysis for protein and carbohydare fractions, energy and digestible nutrient estimated, stastical analyses performed to assess genetic variations for traits among vaieties. Significant genetic variation ( < 0.05) for grain yield, grain density, sieving percentage, crude protein, ether extract, neutral and acid detergent fiber, cellulose, lignin, neutral and acid detergent insoluble nitrogen were observed in grains of eight oat varieties. All protein fractions exhibited significant differences ( < 0.05). Total carbohydrate content ranged significantly ( < 0.05) from 73 % to 79 %. The grains contained higher levels of intermediately degradable starch and pectin (54.12-60.16 %) compared to the slowly degradable cell wall (26-33 %), lignin bounded cell wall (6-10 %), and rapidly degradable sugars (2-8%). Significant variation ( < 0.05) was observed in terms of gross energy, digestible energy, metabolizable energy, net energy for maintenance and lactation about (2 Mcal/kg dry matter), gain (1.6-1.8 Mcal/kg dry matter), total digestible nutrients, digestible dry matter, rumen degradable protein, and total digestible nutrients related to crude protein, fatty acid, neutral detergent fiber, and non-fiber carbohydrate. Organic matter and ether extract were positively associated ( < 0.01) with total digestible nutrients, digestible and metabolizable energy, dry matter digestible and truly digestible non fibrous cabohydrates, while neutral and acid detergent fiber and cellulose showed negative correlation. The research shows that oat varieties vary widely in their yield, physical features, and nutritional content, offering potential for breeding better varieties for both animal feed and industrial uses.
PubMed: 38813156
DOI: 10.1016/j.heliyon.2024.e31541 -
Animal Nutrition (Zhongguo Xu Mu Shou... Jun 2024This study investigated the effects of β-alanine (β-Ala) on rumen fermentation, nutrient digestibility, nitrogen (N) metabolism, plasma biochemical parameters, and...
Impact of dietary supplementation with β-alanine on the rumen microbial crude protein supply, nutrient digestibility and nitrogen retention in beef steers elucidated through sequencing the rumen bacterial community.
This study investigated the effects of β-alanine (β-Ala) on rumen fermentation, nutrient digestibility, nitrogen (N) metabolism, plasma biochemical parameters, and rumen bacterial communities in beef steers. Six steers with initial liveweight of 252.8 ± 5.2 kg and 3 treatments of supplementing with 0, 30, or 60 g β-Ala per day to basal diet were allocated in a replicated 3 × 3 Latin square design. Each experimental period was 20 d, of which the first 15 d were for adaptation and the subsequent 5 d were for sampling. The results showed that β-Ala linearly increased the ruminal concentration of microbial crude protein (MCP) ( = 0.005), but it did not affect the ruminal concentrations of ammonia N and total volatile fatty acids ( > 0.10). β-Ala also linearly increased the dry matter (DM) ( = 0.009), organic matter (OM) ( = 0.017) and crude protein (CP) ( = 0.043) digestibility, tended to decrease the acid detergent fiber digestibility ( = 0.077), but it did not affect the neutral detergent fiber digestibility ( = 0.641). β-Ala quadratically increased the relative abundance of ruminal Bacteroidota ( = 0.021) at the phylum level, and increased ( = 0.028) and ( = 0.014), and decreased the relative abundance of ( = 0.009) at the genus level. Feeding steers with β-Ala linearly increased the urinary N ( = 0.006), urea excretions ( = 0.002) and the N retention ( = 0.004), but it did not affect the N utilization efficiency ( = 0.120). β-Ala quadratically increased the plasma concentration of the total antioxidant capacity ( = 0.011) and linearly increased the plasma concentration of insulin-like growth factor-1 ( < 0.001). In summary, dietary supplementation with β-Ala improved the rumen MCP supply and increased the digestibility of DM, OM, CP and the N retention. Further research is necessary to verify the ruminal degradability of β-Ala and to investigate the mechanism of the impact of absorbed β-Ala on the anti-oxidative ability in steers.
PubMed: 38808018
DOI: 10.1016/j.aninu.2024.02.006 -
PloS One 2024In this investigation, we explore the harnessing of bamboo shoot residues (BSR) as a viable source for ruminant feed through fungal treatment, with the overarching...
In this investigation, we explore the harnessing of bamboo shoot residues (BSR) as a viable source for ruminant feed through fungal treatment, with the overarching objective of elevating feed quality and optimizing bamboo shoot utilization. The white-rot fungi (Wr.fungi), Aspergillus niger (A.niger), and its co-cultures (A.niger&Wr.fungi) were employed to ferment BSR. And the impact of different fermentation methods and culture time on the chemical composition (Crude protein Ash, neutral detergent fibre and acid detergent fibers), enzyme activity (Cellulase, Laccase, Filter paperase and Lignin peroxidase activities), and rumen digestibility in vitro were assessed. The findings reveal a nota ble 30.39% increase in crude protein in fermented BSR, accompanied by respective decreases of 13.02% and 17.31% in acid detergent fiber and neutral detergent fibre content. Enzyme activities experienced augmentation post-fermentation with A.niger&Wr.fungi. Specifically, the peak Cellulase, Laccase, and Lignin peroxidase activities for BSR with Wr.fungi treatment reached 748.4 U/g, 156.92 U/g, and 291.61 U/g, respectively, on the sixth day of fermentation. Concurrently, NH3-N concentration exhibited an upward trend with prolonged fermentation time. Total volatile fatty acids registered a decline, and the Acetate/Propionate ratio reached its nadir after 6 days of fermentation under the A.niger&Wr.fungi treatment. These outcomes furnish a theoretical foundation for the development of ruminant feeds treated via fungal co-culture.
Topics: Animals; Animal Feed; Fermentation; Ruminants; Aspergillus niger; Plant Shoots; Rumen; Fungi
PubMed: 38805421
DOI: 10.1371/journal.pone.0302185 -
Methods and Protocols May 2024DNA impurities can impact the safety of genetically engineered pharmaceuticals; thus, a specific limit value must be set for them during marketing authorisation. This...
DNA impurities can impact the safety of genetically engineered pharmaceuticals; thus, a specific limit value must be set for them during marketing authorisation. This particularly applies to mRNA vaccines, as large quantities of DNA templates are used for their production. Furthermore, when quantifying the total DNA content in the final product, we must observe that, in addition to the mRNA active ingredient, DNA impurities are also encased in lipid nanoparticles and are therefore difficult to quantify. In fact, the manufacturer of the mRNA vaccine Comirnaty (BioNTech/Pfizer) only measures DNA impurities in the active substance by means of a quantitative polymerase chain reaction (qPCR), whose DNA target sequence is less than just 1% of the originally added DNA template. This means that no direct DNA quantification takes place, and compliance with the limit value for DNA contamination is only estimated from the qPCR data using mathematical extrapolation methods. However, it is also possible to dissolve the lipid nanoparticles with a detergent to directly measure DNA contamination in the final product by using fluorescence spectroscopic methods. Experimental testing of this approach confirms that reliable values can be obtained in this way.
PubMed: 38804335
DOI: 10.3390/mps7030041 -
Animal Nutrition (Zhongguo Xu Mu Shou... Jun 2024For the agroecosystems of the dairy cow industry, dietary carbohydrate (starch, neutral detergent fiber [NDF]) and fat could directly affect rumen methane emissions and...
For the agroecosystems of the dairy cow industry, dietary carbohydrate (starch, neutral detergent fiber [NDF]) and fat could directly affect rumen methane emissions and host energy utilization. However, the relationships among diet, lactation performance, and methane emissions need to be further determined to assist dairy farms to adjust diet formulations and feeding strategies for environmental and production management. A meta-analysis was conducted in the current study to explore quantitative patterns of dietary fat and carbohydrate at different levels in balancing lactation performance and environment sustainability of dairy cows, and to establish a methane emission prediction model using the artificial neural network (ANN) model. The results showed that the regression relationship between dietary fat, carbohydrate and methane emissions could be shown by the following models: methane = 106.78 + (14.86 × DMI), = 0.80; methane = 443.17 - (46.41 × starch/NDF), = 0.76; and methane = 388.91 + (31.40 × fat) - (5.42 × fat), = 0.80. The regression relationships between dietary fat, carbohydrate and lactation performance could be shown by the following models: milk fat yield = 1.08 + (0.43 × starch/NDF) - [0.34 × (starch/NDF)], = 0.79; milk protein yield = 0.68 + (0.15 × fat) - (0.016 × fat), = 0.82. In the structural equation model, we found that when formulating dietary carbohydrates and fats, it was necessary to balance the relationship between methane emissions and lactation performance. Specifically, dietary starch/NDF was lower than 0.63 (extremum point) and dietary fat was between 2.89% and 4.69% (extremum point), it could ensure that the aim of methane emission reduction (methane emissions decrease with increasing dietary starch/NDF and fat) was achieved without losing lactation performance of dairy cows (lactation performance increase with increasing dietary starch/NDF and fat). Finally, we established the ANN model to predict methane emissions (training set: = 0.62; validation set: = 0.61).
PubMed: 38800741
DOI: 10.1016/j.aninu.2024.02.004