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1.
Sci Total Environ ; 856(Pt 2): 159106, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36183774

RESUMO

Microplastics are persistent and complex contaminants that have recently been found in freshwater systems, raising concerns about their presence in aquatic organisms. Plastics tend to be seen as an inert material; however, it is not well known if exposure to plastics for a prolonged time, in combination with organic chemicals, causes organism mortality. Ingestion of microplastics in combination with another pollutant may affect a host organism's fitness by altering the host microbiome. In this study, we investigated how microplastics interact with other pollutants in this multi-stress system, and whether they have a synergistic impact on the mortality of an aquatic organism and its microbiome. We used wild water boatmen Hemiptera (Corixidae) found at lake Erken located in east-central Sweden in a fully factorial two-way microcosm experiment designed with polystyrene microspheres and a commonly used detergent. The microplastic-detergent interaction is manifested as a significant increase in mortality compared to the other treatments at 48 h of exposure. The diversity of the microbial communities in the water was significantly affected by the combined treatment of microplastics and the detergent while the microbial communities in the host were affected by the treatments with microplastics and the detergent alone. Changes in relative abundance in Gammaproteobacteria (family Enterobacteriaceae), were observed in the perturbed treatments mostly associated with the presence of the detergent. This confirms that microplastics can interact with detergents having toxic effects on wild water boatmen. Furthermore, microplastics may impact wild organisms via changes in their microbial communities.


Assuntos
Microbiota , Poluentes Químicos da Água , Microplásticos/toxicidade , Plásticos/toxicidade , Detergentes , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Organismos Aquáticos , Lagos , Água
2.
J Colloid Interface Sci ; 629(Pt A): 794-804, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36099847

RESUMO

Interactions between biomolecules are ubiquitous in nature and crucial to many applications including vaccine development; environmentally friendly textile detergents; and food formulation. Using small angle X-ray scattering and structure-based molecular simulations, we explore protein-protein interactions in dilute to semi-concentrated protein solutions. We address the pertinent question, whether interaction models developed at infinite dilution can be extrapolated to concentrated regimes? Our analysis is based on measured and simulated osmotic second virial coefficients and solution structure factors at varying protein concentration and for different variants of the protein Thermomyces Lanuginosus Lipase (TLL). We show that in order to span the dilute and semi-concentrated regime, any model must carefully capture the balance between spatial and orientational correlations as the protein concentration is elevated. This requires consideration of the protein surface morphology, including possible patch interactions. Experimental data for TLL is most accurately described when assuming a patchy interaction, leading to dimer formation. Our analysis supports that the dimeric proteins predominantly exist in their open conformation where the active site is exposed, thereby maximising hydrophobic attractions that promote inter-protein alignment.


Assuntos
Ascomicetos , Eurotiales , Detergentes , Ascomicetos/metabolismo , Lipase/química , Proteínas , Soluções
3.
J Hazard Mater ; 442: 130046, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36182893

RESUMO

In this work, we successfully developed an intriguing preparation strategy to reduce the size-dependent effect of nanoplastics (NPLs), which is the limitation of NPLs quantification by surface-enhanced Raman scattering (SERS). This simple and low-cost technique enabled us to quantify different sizes (i.e., 100, 300, 600, and 800 nm) of polystyrene nanospheres (PS NSs) in various aqueous media. The SERS substrate was simply prepared by sputtering gold particles to cover on a glass cover slide. By dissolving PS NSs in toluene and preconcentrating by coffee-ring effect, SERS measurement can quantify NPLs at a very low concentration with a limit of detection (LOD) of approximately 0.10-0.26 µg/mL. The experiment was also conducted in the presence of interferences, including salts, sugars, amino acids, and detergents. The method was validated for quantitative analysis using a mixture of 100-, 300-, 600-, and 800-nm PS NSs in a ratio of 1:1:1:1 in real-world media (i.e., tap water, mineral water, and river water), which successfully approaches the evaluation of PS NSs in the range of 10-40 µg/mL with an LOD of approximately 0.32-0.52 µg/mL.


Assuntos
Águas Minerais , Análise Espectral Raman , Análise Espectral Raman/métodos , Microplásticos , Poliestirenos/química , Sais , Detergentes , Ouro/química , Tolueno , Amino Açúcares
4.
Methods Mol Biol ; 2558: 1-10, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36169851

RESUMO

Procedures are described for the purification of the mitochondrial-bound enzymes human and bovine monoamine oxidases A and B (MAO A and B) from placental and liver tissue sources, respectively. Enzyme purification follows isolation of the mitochondria and preparation of outer membrane particles. The membrane-bound enzymes are solubilized by treatment of membranes with phospholipases and detergent extraction. Functional bovine MAO B is purified by polymer fractionation and differential centrifugation. Functional human MAO A is purified by ion-exchange DEAE-Sepharose chromatography.


Assuntos
Detergentes , Mitocôndrias Hepáticas , Animais , Bovinos , Feminino , Humanos , Mamíferos , Monoaminoxidase , Fosfolipases , Placenta , Polímeros , Gravidez
5.
Methods Mol Biol ; 2558: 11-22, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36169852

RESUMO

Procedures are described for the heterologous expression and purification of the mitochondrial-bound enzymes human and rat monoamine oxidases A and B and zebrafish MAO in the yeast Pichia pastoris. Enzyme expression is under control of a methanol oxidase promoter and similar procedures have been developed for the preparation of membrane particles and detergent solubilization of the functional enzymes. Similarities and differences are described in the procedures for purification of the respective enzymes using standard column chromatographic techniques to provide enzyme yields in the range of 100-300 mg from 1 L of cell culture.


Assuntos
Eucariotos , Pichia , Animais , Detergentes/metabolismo , Detergentes/farmacologia , Eucariotos/metabolismo , Humanos , Monoaminoxidase/genética , Pichia/genética , Pichia/metabolismo , Ratos , Proteínas Recombinantes/metabolismo , Saccharomycetales , Peixe-Zebra/metabolismo
6.
Methods Mol Biol ; 2558: 115-122, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36169859

RESUMO

The interest in monoamine oxidases A and B (MAO A and B) is due to their central role in regulating the balance of neurotransmitters, both in the central nervous system and in peripheral organs. As validated drug targets for depression and Parkinson's disease, the elucidation of their crystal structures was an essential step to guide drug design investigations. The development of the heterologous expression system of MAO B in Pichia pastoris and the identification of the detergent, buffer, and precipitant conditions allowed to determine the first crystal structure of human MAO B in 2002. A detailed protocol to obtain reproducible MAO B crystals is described.


Assuntos
Monoaminoxidase , Doença de Parkinson , Cristalização , Detergentes , Desenho de Fármacos , Humanos , Monoaminoxidase/genética , Monoaminoxidase/metabolismo
7.
Molecules ; 27(21)2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36364294

RESUMO

Detergent formulations for cleaning a carbonized soil-degreasers-typically comprise surfactants, organic solvents, phosphate-based cleaning agents, and alkaline agents, which results in high pH values (>11) that raise human and environmental risks. It is important to develop eco-friendly and safer degreasers, while maintaining their cleaning efficiency. In this work, simple degreaser formulations, with a pH below 11 and without phosphates, were developed by using a mixture of solvent, surfactant, and water to remove carbonized soil. The efficiency of the new degreaser formulations (with 5 wt% solvent, 5 wt% nonionic or ionic surfactant, and 90 wt% water) was evaluated by an abrasion test in the removal of carbonized soil from ceramic and stainless steel surfaces and compared with a commercial product. The results obtained show that the formulations comprising isopropylene glycol (IPG) with C11-C13 9EOs and diethylene glycol butyl ether (BDG) with octyltrimethylammonium octanoate ([N1118][C8O2]) present the best cleaning efficiency for both surfaces. The composition of these formulations was optimized for each surface using a mixture design. The resulting formulations, despite having a simpler composition, a pH lower than 11, and being phosphate-free, presented a cleaning efficiency equal or slightly higher than the commercial control. These results show that it is possible to design degreasers that are much less aggressive to the environment and user, while simultaneously fulfilling the market requirements.


Assuntos
Detergentes , Solo , Humanos , Tensoativos/química , Água , Solventes
8.
Molecules ; 27(21)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36364455

RESUMO

Bicelles are disk-shaped models of cellular membranes used to study lipid-protein interactions, as well as for structural and functional studies on transmembrane proteins. One challenge for the incorporation of transmembrane proteins in bicelles is the limited range of detergent and lipid combinations available for the successful reconstitution of proteins in model membranes. This is important, as the function and stability of transmembrane proteins are very closely linked to the detergents used for their purification and to the lipids that the proteins are embedded in. Here, we expand the toolkit of lipid and detergent combinations that allow the formation of stable bicelles. We use a combination of dynamic light scattering, small-angle X-ray scattering and cryogenic electron microscopy to perform a systematic sample characterization, thus providing a set of conditions under which bicelles can be successfully formed.


Assuntos
Bicamadas Lipídicas , Surfactantes Pulmonares , Bicamadas Lipídicas/química , Tensoativos , Detergentes/química , Espectroscopia de Ressonância Magnética , Micelas , Proteínas de Membrana/química
9.
Arerugi ; 71(9): 1136-1142, 2022.
Artigo em Japonês | MEDLINE | ID: mdl-36372425

RESUMO

Cocamidopropyl betaine (CAPB) is an amphoteric surfactant. It has several functions, including producing effervescence and washing effects, and thus, it is used in many cleansing products, such as shampoo and liquid body cleansers. Recently, it has become clear that some impurities that arise during the manufacturing process can have sensitizing effects. Herein, we report a case of allergic contact dermatitis caused by detergents containing CAPB, in which an impurity was determined to be the possible causative agent by patch testing and chemical analysis.A 64-year-old Japanese female developed a skin rash on the hairlines of her forehead and nuchal region one month before her first visit to our clinic. Later, the rashes, which were composed of desquamative erythema, expanded to her face, neck, upper back, and chest. Patch tests produced positive results for a shampoo and liquid body cleanser (1% aq.) that she had used as well as for CAPB (1% aq.); lauramidopropyl betaine (LAPB) (1% aq.); and lauramidopropyl dimethylamine (LAPDMA) (0.05% aq.), which is an impurity of CAPB. The rashes resolved completely after we instructed her to use products without CAPB and LAPB. When issuing such instructions, clinicians should have correct knowledge about surfactants, such as the differences between cosmetic ingredient names and quasi-drug ingredient names.


Assuntos
Betaína , Dermatite Alérgica de Contato , Humanos , Feminino , Pessoa de Meia-Idade , Betaína/efeitos adversos , Detergentes/efeitos adversos , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/etiologia , Testes do Emplastro/efeitos adversos , Testes do Emplastro/métodos , Tensoativos
10.
Arch Microbiol ; 204(12): 705, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36374350

RESUMO

Industrial important proteases and lipases are in increasing demand for various biotechnological applications. In the present study, the concomitantly produced protease and lipase by Haloferax sp. strain GUBF 2 were simultaneously purified as a heterogeneous lipase (45 and 66 kDa) and homogeneous protease (180 kDa); with 28.3 and 31.36 fold purity, respectively using Sephadex G-200. The aforementioned extremozymes were active at pH 3-13, 20-80 °C, 1-5 M NaCl, with optimal activity at pH 6, 70 °C, and 3 M NaCl, thus exhibiting attributes of true haloextremozymes. The Km and Vmax of purified lipase were 3.47 mM and 16.2 U/mL, while protease were 3.29 mg/mL and 28.5 U/mL, respectively. FTIR bands corresponding to the vibrations of amide II and amide III were detected in haloextremozymes which could perhaps be used to determine the secondary structure of the purified proteins. Furthermore, the activity of both enzymes was stimulated by Ca2+ and inhibited by 10 mM Hg2+ and phenylmethyl sulphonyl fluoride (PMSF). Additionally, these haloextremozymes are stable in the presence of detergent additives and organic solvents. In addition, purified protease displayed 74.3 ± 4.85% in-vitro blood clot dissolution activity. Conclusively this study revealed the key features, unusual properties, and possible biomedical applications of detergent-stable and organic solvent-tolerant haloextremozymes from Haloferax sp. strain GUBF 2 to date unexplored.


Assuntos
Haloferax , Lipase , Lipase/metabolismo , Solventes/química , Peptídeo Hidrolases/metabolismo , Detergentes/farmacologia , Detergentes/química , Estabilidade Enzimática , Haloferax/metabolismo , Cloreto de Sódio , Endopeptidases/metabolismo , Amidas , Concentração de Íons de Hidrogênio , Temperatura
11.
Int J Mol Sci ; 23(21)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36362071

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the current COVID-19 pandemic. In SARS-CoV-2, the channel-forming envelope (E) protein is almost identical to the E protein in SARS-CoV, and both share an identical α-helical channel-forming domain. Structures for the latter are available in both detergent and lipid membranes. However, models of the extramembrane domains have only been obtained from solution NMR in detergents, and show no ß-strands, in contrast to secondary-structure predictions. Herein, we have studied the conformation of purified SARS-CoV-2 E protein in lipid bilayers that mimic the composition of ER-Golgi intermediate compartment (ERGIC) membranes. The full-length E protein at high protein-to-lipid ratios produced a clear shoulder at 1635 cm-1, consistent with the ß-structure, but this was absent when the E protein was diluted, which instead showed a band at around 1688 cm-1, usually assigned to ß-turns. The results were similar with a mixture of POPC:POPG (2-oleoyl-1-palmitoyl-sn-glycero-3-phosphocholine/3-glycerol) and also when using an E-truncated form (residues 8-65). However, the latter only showed ß-structure formation at the highest concentration tested, while having a weaker oligomerization tendency in detergents than in full-length E protein. Therefore, we conclude that E monomer-monomer interaction triggers formation of the ß-structure from an undefined structure (possibly ß-turns) in at least about 15 residues located at the C-terminal extramembrane domain. Due to its proximity to the channel, this ß-structure domain could modulate channel activity or modify membrane structure at the time of virion formation inside the cell.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Detergentes , Pandemias , Bicamadas Lipídicas/química
12.
Trop Anim Health Prod ; 54(6): 364, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36316411

RESUMO

The objective of this study was to examine the effect of increasing levels of red propolis extract (RPE) on the intake, digestibility, feeding behavior, rumen parameters, metabolic parameters, and performance of feedlot lambs. Thirty-five uncastrated male Santa Inês lambs with an initial weight of 17.08 ± 2.36 kg were used in a completely randomized design with five treatments (0, 7, 14, 21, or 28 mL RPE/animal/day). The animals were confined for 68 days. Red propolis extract induced a negative quadratic response (P < 0.05) in the intakes of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, non-fibrous carbohydrates, and metabolizable energy. The apparent digestibility coefficients of dry matter, organic matter, and neutral detergent fiber, as well as the rumen concentration of NH3-N, also responded quadratically (P < 0.05) to RPE. Feeding efficiency increased linearly (P < 0.05) with the inclusion of RPE, whereas rumination efficiency was maximum (P < 0.05) at the RPE level of 16 mL/day. Red propolis extract induced a linear response (P < 0.05) in serum total protein, albumin, creatinine, and gamma-glutamyl transpeptidase. There was a quadratic effect on final body weight and average daily gain with minimum values for inclusion of RPE of 12.89 mL/day and 10.93 mL/day respectively. Feed efficiency rose linearly (P < 0.05) with the increasing concentrations of RPE in the diet. The inclusion of 21 mL RPE/day (8.5 mg total flavonoids/mL) in the diet of feedlot lambs is recommended to reduce the rumen NH3-N production and increase the animals' performance.


Assuntos
Própole , Rúmen , Ovinos , Animais , Masculino , Rúmen/metabolismo , Digestão , Detergentes/metabolismo , Detergentes/farmacologia , Fibras na Dieta/metabolismo , Dieta/veterinária , Extratos Vegetais/farmacologia , Ração Animal/análise
13.
Virol J ; 19(1): 193, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36414943

RESUMO

A global pandemic is underway caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 genome, like its predecessor SARS-CoV, contains open reading frames that encode accessory proteins involved in virus-host interactions active during infection and which likely contribute to pathogenesis. One of these accessory proteins is 7b, with only 44 (SARS-CoV) and 43 (SARS-CoV-2) residues. It has one predicted transmembrane domain fully conserved, which suggests a functional role, whereas most variability is contained in the predicted cytoplasmic C-terminus. In SARS-CoV, 7b protein is expressed in infected cells, and the transmembrane domain was necessary and sufficient for Golgi localization. Also, anti-p7b antibodies have been found in the sera of SARS-CoV convalescent patients. In the present study, we have investigated the hypothesis that SARS-2 7b protein forms oligomers with ion channel activity. We show that in both SARS viruses 7b is almost completely α-helical and has a single transmembrane domain. In SDS, 7b forms various oligomers, from monomers to tetramers, but only monomers when exposed to reductants. Combination of SDS gel electrophoresis and analytical ultracentrifugation (AUC) in both equilibrium and velocity modes suggests a dimer-tetramer equilibrium, but a monomer-dimer-tetramer equilibrium in the presence of reductant. This data suggests that although disulfide-linked dimers may be present, they are not essential to form tetramers. Inclusion of pentamers or higher oligomers in the SARS-2 7b model were detrimental to fit quality. Preliminary models of this association was generated with AlphaFold2, and two alternative models were exposed to a molecular dynamics simulation in presence of a model lipid membrane. However, neither of the two models provided any evident pathway for ions. To confirm this, SARS-2 p7b was studied using Planar Bilayer Electrophysiology. Addition of p7b to model membranes produced occasional membrane permeabilization, but this was not consistent with bona fide ion channels made of a tetrameric assembly of α-helices.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Detergentes , Fases de Leitura Aberta , Citoplasma
14.
Nanoscale ; 14(44): 16581-16589, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36314744

RESUMO

We report a scalable fabrication method to generate exosome-mimicking nanovesicles (ENVs) by using a biocompatible, cell-binding lipid detergent during cell extrusion. A PEGylated mannosylerythritol lipid (MELPEG) detergent was rationally engineered to strongly associate with phospholipid membranes to increase cell membrane deformability and the corresponding friction force during extrusion and to enhance the dispersibility of ENVs. Compared to cell extrusion without detergent, cell extrusion in the presence of MELPEG increased the ENV production yield by approximately 20 times and cellular protein content per MELPEG-functionalized ENV by approximately 2-fold relative to that of unmodified ENVs. We verified that MELPEG strongly binds to ENV membranes and increases membrane deformability via expansion/swelling while preserving the integrity of the phospholipid bilayer structure. The results highlight that the MELPEG-aided cell extrusion process broadly applies to various cell lines; hence, it could be helpful in the production of ENVs for tissue regeneration, drug delivery, and cancer nanomedicine.


Assuntos
Exossomos , Exossomos/química , Detergentes/análise , Sistemas de Liberação de Medicamentos , Fosfolipídeos , Polietilenoglicóis
15.
Am J Trop Med Hyg ; 107(5): 1083-1090, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36191872

RESUMO

The objective of our study was to develop and test observational methods to evaluate COVID-19 preventive hygiene behaviors and physical distancing, and to evaluate the effectiveness of a government mandate on indoor fully covered mask wearing. An observational study was conducted of 4,736 individuals from April to October 2021 using 5-hour and rapid (10-minute) structured observations and spot checks to evaluate mask-wearing, handwashing, and physical-distancing behaviors, and the functionality of handwashing stations in 161 indoor public spaces across Bukavu, Democratic Republic of the Congo (DRC). Sixteen percent of individuals entering indoor public spaces were wearing a mask that fully covered their nose and mouth (fully covered mask wearing). Fully covered mask wearing was lowest inside schools (1%), universities (2%), religious establishments (22%), and health facility wards (28%). Overall physical distancing of more than 1-m inside indoor public spaces was 22%, and was lowest inside schools and religious establishments (7%). Thirty-nine percent of handwashing stations had water and a cleansing agent present. Ten percent of individuals washed their hands with a cleansing agent before entering an indoor space. Overall, fully covered mask wearing was similar for 5-hour and rapid structured observations (16% versus 15%). The odds of fully covered mask wearing was significantly greater with increased government enforcement of mask wearing in public spaces through fines (odds ratio, 2.72; 95% CI, 1.02-7.30). This study presents rigorous methods using structured observations to assess government mandates and programs on COVID-19 preventive hygiene behaviors in indoor public spaces in settings globally.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Desinfecção das Mãos , SARS-CoV-2 , República Democrática do Congo/epidemiologia , Distanciamento Físico , Detergentes , Higiene
16.
Anal Chem ; 94(41): 14151-14158, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36200347

RESUMO

One of the biggest challenges in membrane protein (MP) research is to secure physiologically relevant structural and functional information after extracting MPs from their native membrane. Amphipathic polymers represent attractive alternatives to detergents for stabilizing MPs in aqueous solutions. The predominant polymers used in MP biochemistry and biophysics are amphipols (APols), one class of which, styrene maleic acid (SMA) copolymers and their derivatives, has proven particularly efficient at MP extraction. In order to examine the relationship between the chemical structure of the polymers and their ability to extract MPs from membranes, we have developed two novel classes of APols bearing either cycloalkane or aryl (aromatic) rings, named CyclAPols and ArylAPols, respectively. The effect on solubilization of such parameters as the density of hydrophobic groups, the number of carbon atoms and their arrangement in the hydrophobic moieties, as well as the charge density of the polymers was evaluated. The membrane-solubilizing efficiency of the SMAs, CyclAPols, and ArylAPols was compared using as models (i) two MPs, BmrA and a GFP-fused version of LacY, overexpressed in the inner membrane of Escherichia coli, and (ii) bacteriorhodopsin, naturally expressed in the purple membrane of Halobacterium salinarum. This analysis shows that, as compared to SMAs, the novel APols feature an improved efficiency at extracting MPs while preserving native protein-lipid interactions.


Assuntos
Bacteriorodopsinas , Cicloparafinas , Carbono , Detergentes/química , Lipídeos , Maleatos/química , Polímeros/química , Poliestirenos/química
17.
J Dairy Sci ; 105(12): 9652-9665, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36270875

RESUMO

Our objective was to determine the dose-response effects of calcium salts of palm fatty acids (CSPF) on nutrient digestibility and production responses of early-lactation dairy cows grazing on tropical pastures and to evaluate carryover effects throughout mid and late lactation. Forty multiparous dairy cows (Jersey × Holstein) with (mean ± standard error of the mean) 20 ± 1.69 kg of milk/d and 20 ± 5.0 d in milk were used in a randomized complete block design. During the treatment period, all cows were kept in a grazing system. The treatments were offered for 90 d (treatment period) and consisted of 4 increasing levels of CSPF: 0 (0 kg/d), 0.2 (0.2 kg/d), 0.4 (0.4 kg/d), and 0.6 (0.6 kg/d). Each treatment had 10 animals. Increasing CSPF from 0 to 0.6 kg/d replaced an equivalent amount of a corn-based concentrate supplement offered at 10 kg/d on an as-fed basis (8.96 kg/d as a dry matter basis). All cows were housed and received a diet without fat inclusion fed as total mixed ration once a day from 91 to 258 d of the experiment (carryover period). During the treatment period, increasing CSPF linearly decreased dry matter intake (1.20 kg/d), linearly increased neutral detergent fiber digestibility (3.90 percentage units), and quadratically increased total fat digestibility (6.30 percentage units at 0.4 kg/d CSPF). Increasing CSPF linearly increased the yields of milk (4.10 kg/d), milk fat (0.11 kg/d), milk lactose (0.19 kg/d), energy-corrected milk (ECM; 3.30 kg/d), and feed efficiency (ECM/dry matter intake, 0.34 kg/kg), and linearly decreased milk protein content (0.38 g/100 g), body weight change (0.05 kg/d), and body condition score (0.37). We observed interactions between CSPF and time during the carryover period. Overall, CSPF supplementation linearly increased or tended to increase milk yield until 202 d of the experiment with a similar pattern observed for all the other yield variables. In conclusion, supplementing CSPF from 0 to 0.6 kg/d during 90 d increased neutral detergent fiber and total fat digestibility and the yields of milk, milk fat, and ECM in early-lactation dairy cows grazing on tropical pastures. Most production measurements linearly increased during the treatment period, indicating that 0.6 kg/d CSPF was the best dose. Also, supplementing CSPF from 0 to 0.6 kg/d for 90 d during early lactation had positive carryover effects across mid and late lactation.


Assuntos
Ácidos Graxos , Sais , Feminino , Bovinos , Animais , Ácidos Graxos/metabolismo , Sais/metabolismo , Cálcio/metabolismo , Detergentes , Lactação/fisiologia , Dieta/veterinária , Suplementos Nutricionais , Período Pós-Parto , Fibras na Dieta/metabolismo , Digestão , Ração Animal/análise
18.
Biochemistry (Mosc) ; 87(10): 1119-1129, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36273880

RESUMO

To elucidate the mechanism of site-selective chemical replacement of chromophores in the reaction centers (RCs) of photosynthetic bacteria by external pigments, we investigated how the efficiency of incorporation of plant pheophytin a (Pheo) into the binding sites for bacteriopheophytin a molecules (BPheo) in the isolated Rhodobacter sphaeroides R-26 RCs depended on the incubation medium temperature, Pheo aggregation state, and the presence of organic solvent (acetone). When Pheo was in a form of monomers in free detergent micelles in a water-detergent incubation medium, the degree of selective replacement of photochemically inactive BPheo HB molecules upon incubation of the RC/Pheo mixture at 5°C was ~15%. The exchange efficiency increased to 40% upon incubation at 25°C and reached 100% at the same temperature when 10% acetone was added to the incubation medium. At both 5 and 25°C, the degree of pigment exchange increased approximately twice, when a mixture of Pheo monomers and dimers in the presence of 10% acetone was used as the incubation medium. The removal of acetone from this medium with the preservation of pigment forms led to a significant decrease in the efficiency of Pheo incorporation. The effect of acetone on the pigment exchange was also observed at an elevated incubation temperature (43.5°C), when functionally active BPheo HA molecules were partially replaced. The results are discussed in terms of the mechanism according to which (i) the temperature-dependent internal movements of the RC protein facilitate the release of the BPheo molecule from the binding site with simultaneous insertion of the Pheo molecule into the same site in a coupled process, (ii) the role of temperature largely depends on the steric accessibility of binding pockets in the RC protein, (iii) the incorporation of Pheo occurs from a pool of monomeric molecules included in the RC-detergent micelles, and (iv) the presence of acetone in the incubation medium facilitates the exchange of Pheo monomers between micelles in the solution and the detergent belt of the RC complex.


Assuntos
Complexo de Proteínas do Centro de Reação Fotossintética , Rhodobacter sphaeroides , Rhodobacter sphaeroides/metabolismo , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Detergentes , Micelas , Acetona/metabolismo , Água/metabolismo , Solventes , Transporte de Elétrons
19.
PLoS Negl Trop Dis ; 16(10): e0010788, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36190932

RESUMO

Host cell invasion is a critical step for infection by Trypanosoma cruzi, the agent of Chagas disease. In natural infection, T. cruzi metacyclic trypomastigote (MT) forms establish the first interaction with host cells. The gp35/50 mucin molecules expressed in MT have been implicated in cell invasion process, but the mechanisms involved are not well understood. We performed a series of experiments to elucidate the mode of gp35/50-mediated MT internalization. Comparing two parasite strains from genetically divergent groups, G strain (TcI) and CL strain (TcVI), expressing variant forms of mucins, we demonstrated that G strain mucins participate in MT invasion. Only G strain-derived mucins bound to HeLa cells in a receptor-dependent manner and significantly inhibited G strain MT invasion. CL strain MT internalization was not affected by mucins from either strain. HeLa cell invasion by G strain MT was associated with actin recruitment and did not rely on lysosome mobilization. To examine the involvement of annexin A2, which plays a role in actin dynamic, annexin A2-depleted HeLa cells were generated. Annexin A2-deficient cell lines were significantly more resistant than wild type controls to G strain MT invasion. In a co-immunoprecipitation assay, to check whether annexin A2 might be the receptor for mucins, protein A/G magnetic beads crosslinked with monoclonal antibody to G strain mucins were incubated with detergent extracts of MT and HeLa cells. Binding of gp35/50 mucins to annexin A2 was detected. Both G strain MT and purified mucins induced focal adhesion kinase activation in HeLa cells. By confocal immunofluorescence microscopy, colocalization of invading G strain MT with clathrin was visualized. Inhibition of clathrin-coated vesicle formation reduced parasite internalization. Taken together, our data indicate that gp35/50-mediated MT invasion is accomplished through interaction with host cell annexin A2 and clathrin-dependent endocytosis.


Assuntos
Anexina A2 , Doença de Chagas , Trypanosoma cruzi , Actinas/metabolismo , Anexina A2/metabolismo , Anticorpos Monoclonais , Doença de Chagas/parasitologia , Clatrina , Detergentes/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Células HeLa , Humanos , Mucinas/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/fisiologia
20.
Environ Monit Assess ; 194(12): 873, 2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36227369

RESUMO

In this study, the biosurfactants (Bio-SFs) producing bacteria are screened from the selected alkaline lake of Ethiopia, and the potential bacterial strain and their produced Bio-SFs are further characterized. In an initial screening, 25 bacterial isolates were isolated, and among those, the bacterial isolate assigned as CS1 was identified as the most potent producer of Bio-SFs using a subsequent characterization process. The CS1 strain was identified as Serratia sp. via biochemical and molecular methods. An emulsion index (E24) of 69.06 ± 0.11% was obtained for CS1 after 5 days of incubation time at 30 °C. The CS1-extracted Bio-SFs were characterized by Fourier transform infrared (FTIR), and it indicated that the type of biosurfactant produced was a glycolipid. The stability of the crude Bio-SFs was characterized, and the optimal conditions were found to be 80 °C, pH 8, and 3% NaCl, respectively. The extracted Bio-SFs were compatible with tested commercial detergents, and its efficiency increased from 12.2 ± 0.1% to 67.1 ± 0.17% and 70.43 ± 0.11% when combined with commercially available detergent brands in Ethiopia such as Taza and Largo, respectively. This study suggests that the isolated S. marcescens CS1 strain has the potential to produce Bio-SFs that are viable competence to replace the use of synthetic chemicals in the production of commercial detergents.


Assuntos
Detergentes , Tensoativos , Emulsões , Monitoramento Ambiental , Etiópia , Glicolipídeos , Lagos , Serratia , Cloreto de Sódio , Tensoativos/química
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