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1.
J Environ Manage ; 360: 121161, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38761626

RESUMO

Recent attention on the detrimental effects of pharmaceutically active compounds (PhACs) in natural water has spurred researchers to develop advanced wastewater treatment methods. Carbamazepine (CBZ), a widely recognized anticonvulsant, has often been a primary focus in numerous studies due to its prevalence and resistance to breaking down. This study aims to explore the effectiveness of a bio-electrochemical system in breaking down CBZ in polluted water and to assess the potential harmful effects of the treated wastewater. The results revealed bio-electro degradation process demonstrated a collaborative effect, achieving the highest CBZ degradation compared to electrodegradation and biodegradation techniques. Notably, a maximum CBZ degradation efficiency of 92.01% was attained using the bio-electrochemical system under specific conditions: Initial CBZ concentration of 60 mg/L, pH level at 7, 0.5% (v/v) inoculum dose, and an applied potential of 10 mV. The degradation pathway established by identifying intermediate products via High-Performance Liquid Chromatography-Mass Spectrometry, revealed the complete breakdown of CBZ without any toxic intermediates or end products. This finding was further validated through in vitro and in vivo toxicity assays, confirming the absence of harmful remnants after the degradation process.


Assuntos
Biodegradação Ambiental , Carbamazepina , Poluentes Químicos da Água , Carbamazepina/toxicidade , Poluentes Químicos da Água/toxicidade , Águas Residuárias/química , Animais
2.
Int Microbiol ; 2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-37659056

RESUMO

Bisphenol A (BpA) is an endocrine-disrupting substance commonly found in plastics and resins. It is reported that BpA exposure induces lipid accumulation in humans, similar to obesogenic compounds. The main objective of this study is to investigate the removal of BpA using Lactiplantibacillus sp. D10-2, and to examine its potential for reducing BpA-induced lipid accumulation in 3T3-L1 cell line model. The heat-dried cells of Lactiplantibacillus sp. D10-2 showed 69.7% removal efficiency for initial BpA concentration of 10 µg/mL, which was 30.5% higher than the live cells. The absence of metabolites or intermediates in BpA removal studies indicates that the Lactiplantibacillus sp. D10-2 strain removed BpA by adsorption process. The hydrophobic interactions of heat-dried Lactiplantibacillus sp. D10-2 cells were observed to be higher with 33.7% compared to live cells (15.0%), suggesting a stronger ability to bind with BpA. Although the BpA binding onto Lactiplantibacillus sp. D10-2 was not affected by pH, it was confirmed that as the temperature increases, the binding ability got decreased due to mass transfer and diffusion of BpA molecules. Treatment with Lactiplantibacillus sp. D10-2 (0.1, 0.25, 0.5, 1%) reduced lipid accumulation by 61.7, 58.0, 52.7 and 60.4% in 3T3-L1 cells exposed with BpA. In addition, it was confirmed that Lactiplantibacillus sp. D10-2 treatment suppressed the protein expression levels of lipogenesis-related PPARγ and C/EBPα in 3T3-L1 cells. The results of the study suggest that the Lactiplantibacillus sp. D10-2 strain can remove BpA and reduce BpA-accelerated lipid accumulation in 3T3-L1 cells.

3.
J Appl Microbiol ; 134(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37989872

RESUMO

AIM: To assess the effectiveness of Lentilactobacillus parafarraginis A6-2 cell lysate for the removal of aluminum (Al), which induces neurotoxicity, and its protective effect at cellular level. METHODS AND RESULTS: The cell lysate of the selected L. parafarraginis A6-2 strain demonstrated superior Al removal compared to live or dead cells. The Al removal efficiency of L. parafarraginis A6-2 cell lysate increased with decreasing pH and increasing temperature, primarily through adsorption onto peptidoglycan. Neurotoxicity mitigation potential of L. parafarraginis A6-2 was evaluated using C6 glioma cells. C6 cells exposed with increasing concentration of Al led to elevated toxicity and inflammation, which were gradually alleviated upon treatment with L. parafarraginis A6-2. Moreover, Al-induced oxidative stress in C6 cells showed a concentration-dependent reduction upon treatment with L. parafarraginis A6-2. CONCLUSIONS: This study demonstrated that L. parafarraginis A6-2 strain, particularly in its lysate form, exhibited enhanced capability for Al removal. Furthermore, it effectively mitigated Al-induced toxicity, inflammation, and oxidative stress.


Assuntos
Alumínio , Estresse Oxidativo , Humanos , Alumínio/toxicidade , Inflamação , Anti-Inflamatórios/farmacologia
4.
Molecules ; 27(3)2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35164149

RESUMO

Arginine kinase (AK) plays a crucial role in the survival of Daphnia magna, a water flea and a common planktonic invertebrate sensitive to water pollution, owing to the production of bioenergy. AK from D. magna (DmAK) has four highly conserved histidine residues, namely, H90, H227, H284, and H315 in the amino acid sequence. In contrast to DmAK WT (wild type), the enzyme activity of the H227A mutant decreases by 18%. To identify the structure-function relationship of this H227A mutant enzyme, the crystal 3D X-ray structure has been determined and an unfolding assay using anilino-1-naphthalenesulfonic acid (ANS) fluorescence has been undertaken. The results revealed that when compared to the DmAK WT, the hydrogen bonding between H227 and A135 was broken in the H227A crystal structure. This suggests that H227 residue, closed to the arginine binding site, plays an important role in maintaining the structural stability and maximizing the enzyme activity through hydrogen bonding with the backbone oxygen of A135.


Assuntos
Arginina Quinase/química , Proteínas de Artrópodes/química , Daphnia/enzimologia , Animais , Arginina Quinase/genética , Arginina Quinase/metabolismo , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Cristalografia por Raios X , Daphnia/química , Daphnia/genética , Daphnia/metabolismo , Estabilidade Enzimática , Modelos Moleculares , Mutação Puntual , Conformação Proteica , Especificidade por Substrato
5.
Cell Physiol Biochem ; 47(5): 1751-1768, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29953970

RESUMO

BACKGROUND/AIMS: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignant tumors with poor prognosis. Conventional chemotherapies including gemcitabine have failed owing to weak response and side effects. Hence novel treatment regimens are urgently needed to improve the therapeutic efficacy. In this study, we aimed to assess the anticancer activity of melatonin and sorafenib as a novel therapy against PDAC. METHODS: We used various apoptosis assay and PDAC xenograft model to assess anticancer effect in vitro and in vivo. We applied phospho-receptor tyrosine kinase (RTK) array and phospho-tyrosine kinase array to explore the mechanism of the combined therapy. Western blotting, proximity ligation assay, and immunoprecipitation assay were also performed for validation. RESULTS: Melatonin synergized with sorafenib to suppress the growth of PDAC both in vitro and in vivo. The effect was due to increased apoptosis rate of PDAC cells that was accompanied by mitochondria dysfunction. The enhanced anticancer efficacy by the co-treatment could be explained by blockade of PDGFR-ß/STAT3 signaling pathway and melatonin receptor (MT)-mediated STAT3. CONCLUSIONS: Melatonin reinforces the anticancer activity of sorafenib by downregulation of PDGFR-ß/STAT3 signaling pathway and melatonin receptor (MT)-mediated STAT3. The combination of the two agents might be a potential therapeutic strategy for treating PDAC.


Assuntos
Melatonina/farmacologia , Proteínas de Neoplasias/metabolismo , Niacinamida/análogos & derivados , Neoplasias Pancreáticas/tratamento farmacológico , Compostos de Fenilureia/farmacologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores de Melatonina/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Melatonina/agonistas , Niacinamida/agonistas , Niacinamida/farmacologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Compostos de Fenilureia/agonistas , Sorafenibe
6.
Nature ; 471(7340): 651-5, 2011 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-21389988

RESUMO

G-protein-coupled receptors (GPCRs) are seven transmembrane helix (TM) proteins that transduce signals into living cells by binding extracellular ligands and coupling to intracellular heterotrimeric G proteins (Gαßγ). The photoreceptor rhodopsin couples to transducin and bears its ligand 11-cis-retinal covalently bound via a protonated Schiff base to the opsin apoprotein. Absorption of a photon causes retinal cis/trans isomerization and generates the agonist all-trans-retinal in situ. After early photoproducts, the active G-protein-binding intermediate metarhodopsin II (Meta II) is formed, in which the retinal Schiff base is still intact but deprotonated. Dissociation of the proton from the Schiff base breaks a major constraint in the protein and enables further activating steps, including an outward tilt of TM6 and formation of a large cytoplasmic crevice for uptake of the interacting C terminus of the Gα subunit. Owing to Schiff base hydrolysis, Meta II is short-lived and notoriously difficult to crystallize. We therefore soaked opsin crystals with all-trans-retinal to form Meta II, presuming that the crystal's high concentration of opsin in an active conformation (Ops*) may facilitate all-trans-retinal uptake and Schiff base formation. Here we present the 3.0 Å and 2.85 Å crystal structures, respectively, of Meta II alone or in complex with an 11-amino-acid C-terminal fragment derived from Gα (GαCT2). GαCT2 binds in a large crevice at the cytoplasmic side, akin to the binding of a similar Gα-derived peptide to Ops* (ref. 7). In the Meta II structures, the electron density from the retinal ligand seamlessly continues into the Lys 296 side chain, reflecting proper formation of the Schiff base linkage. The retinal is in a relaxed conformation and almost undistorted compared with pure crystalline all-trans-retinal. By comparison with early photoproducts we propose how retinal translocation and rotation induce the gross conformational changes characteristic for Meta II. The structures can now serve as models for the large GPCR family.


Assuntos
Rodopsina/química , Rodopsina/metabolismo , Sítios de Ligação , Sequência Conservada , Cristalização , Cristalografia por Raios X , Subunidades alfa de Proteínas de Ligação ao GTP/química , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Ligantes , Modelos Moleculares , Opsinas/química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Conformação Proteica , Retinaldeído/química , Retinaldeído/metabolismo , Bases de Schiff/química , Eletricidade Estática
7.
Biochemistry (Mosc) ; 82(10): 1129-1139, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29037133

RESUMO

Mus musculus centrin 1 (MmCen1) is located at the cilium of photoreceptor cells connecting the outer segment through signal transduction components to the metabolically active inner segment. In the cilium, MmCen1 is involved in the translocation of transducin between compartments as a result of photoreceptor activation. In this study, we report the crystal structure of wild-type MmCen1 and its Ca2+-binding properties using structure-based mutagenesis. The crystal structure exhibits three structural features, i.e. four Ca2+ equally occupied at each EF-hand motif, structural changes accompanying helix motion at the N- and C-lobes, and adoption of N-C type dimerization when Ca2+ binds to EF-hand I and II in the N-lobe. The presence of MmCen1 dimers was confirmed in solution by native PAGE. Isothermal titration calorimetry data showed sequential binding of Ca2+ at four independent sites. Mutations S45A and D49A in EF-hand I alone disrupted the Ca2+-binding property of the wild-type protein. Based on the crystal structure of MmCen1, we suggest that a dimerization mode between the N- and C-lobes may be required by Ca2+ binding at the N-lobe.


Assuntos
Proteínas de Ligação ao Cálcio/química , Cálcio/metabolismo , Proteínas Cromossômicas não Histona/química , Sequência de Aminoácidos , Animais , Cálcio/química , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Calorimetria , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Cristalografia por Raios X , Dimerização , Humanos , Camundongos , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Alinhamento de Sequência
8.
Arch Microbiol ; 198(8): 737-42, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27154571

RESUMO

Phytoremediation is an in situ, low-cost strategy for cleanup of the sites contaminated with heavy metals. Experiments were conducted to assess the impact of synthetic chelators and plant growth-promoting rhizosphere bacteria (Herbaspirillum sp. GW103) on heavy metal lead (Pb) uptake in Z. mays cultivated in Pb-contaminated soil. The present study investigated the Pb phytoaccumulation rate and plant antioxidant enzyme activities in Z. mays exposed to 100 mg/kg of PbNO3. The combination of gluconic acid (GA) with Herbaspirillum sp. GW103 treatment showed higher Pb solubility (18.9 mg/kg) compared with other chelators. The chemical chelators showed the significant difference in phytoaccumulation as well as antioxidant enzyme activities. The antioxidant enzymes such as catalase, peroxidase and superoxide dismutase activities changed under Pb stress. The study indicated that increased activity of antioxidant enzymes may play as signal inducers to fight against Pb.


Assuntos
Antioxidantes/metabolismo , Quelantes/metabolismo , Herbaspirillum/metabolismo , Chumbo/metabolismo , Nitratos/metabolismo , Poluentes do Solo/metabolismo , Zea mays/metabolismo , Biodegradação Ambiental , Catalase/metabolismo , Gluconatos/metabolismo , Herbaspirillum/enzimologia , Estresse Oxidativo/fisiologia , Peroxidases/metabolismo , Rizosfera , Superóxido Dismutase/metabolismo , Zea mays/microbiologia
9.
Microbiol Immunol ; 60(5): 343-55, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26989992

RESUMO

In traditional Asian medicine, Aralia cordata (AC) is a known as a pain reliever and anti-inflammatory drug. Although several of its biological activities have been reported, the immunomodulatory effects of a hot water extract of AC (HAC) have not yet been described. The aim of this study was to investigate whether HAC modulates the activation of macrophages, which play important roles in innate immune responses against microbial pathogens, and if so, to determine the molecular mechanisms by which HAC mediates this process. It was found that HAC activates bone marrow-derived macrophages (BMDM) and increases amounts of nitric oxide and proinflammatory cytokines in a dose-dependent manner. In addition, HAC was found to induce phosphorylation of NF-κB and mitogen-activated protein kinases (MAPKs), including c-Jun N-terminal kinases, extracellular signal-regulated kinases and p38. Interestingly, these effects were absent in BMDM prepared from myeloid differentiation protein 88-knockout mice. Polysaccharides from HAC exerted stronger immunostimulatory effects than HAC itself. Furthermore, orally administered HAC clearly enhanced clearance of the intracellular pathogen Listeria monocytogenes by boosting innate immune responses. These results demonstrate that HAC exerts immunostimulatory effects through the TLR/MyD88 and NF-κB/MAPK signal transduction pathways.


Assuntos
Aralia/química , Fatores Imunológicos/farmacologia , Listeriose/prevenção & controle , Macrófagos/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Extratos Vegetais/farmacologia , Animais , Imunidade Inata , Fatores Imunológicos/isolamento & purificação , Listeria monocytogenes/imunologia , Listeriose/imunologia , Macrófagos/efeitos dos fármacos , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fator 88 de Diferenciação Mieloide/deficiência , NF-kappa B/metabolismo , Fosforilação , Extratos Vegetais/isolamento & purificação , Processamento de Proteína Pós-Traducional
10.
Curr Microbiol ; 71(3): 311-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26048485

RESUMO

This study investigated the expression rate and molecular modeling of Wzb gene, a low molecular weight protein tyrosine phosphatase, under As stress in Herbaspirillum sp. GW103. Expression of Wzb gene was quantified at transcriptional level through real-time quantitative PCR. The results showed up- and down-regulations of Wzb gene in the presence of As (50 and 100 mg/L). The maximum Wzb transcript expression was 1.2-fold after 72 h exposure to 50 mg/L of As. However, the minimum expression was 0.1-fold after 48 h exposure to 100 mg/L of As. The Wzb protein sequence was retrieved from NCBI sequence database and was used for in silico analysis. 3D structure of Wzb gene was predicted by comparative modeling using modeler 9v9. Further, the model was validated for its quality by Ramachandran plot, ERRAT, Verify 3D, and SAVES server which revealed structure and quality of the Wzb gene model.


Assuntos
Arsênio/toxicidade , Perfilação da Expressão Gênica , Herbaspirillum/efeitos dos fármacos , Herbaspirillum/enzimologia , Proteínas Tirosina Fosfatases/biossíntese , Proteínas Tirosina Fosfatases/química , Modelos Moleculares , Conformação Proteica , Proteínas Tirosina Fosfatases/genética , Reação em Cadeia da Polimerase em Tempo Real , Transcrição Gênica
11.
Nature ; 454(7201): 183-7, 2008 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-18563085

RESUMO

In the G-protein-coupled receptor (GPCR) rhodopsin, the inactivating ligand 11-cis-retinal is bound in the seven-transmembrane helix (TM) bundle and is cis/trans isomerized by light to form active metarhodopsin II. With metarhodopsin II decay, all-trans-retinal is released, and opsin is reloaded with new 11-cis-retinal. Here we present the crystal structure of ligand-free native opsin from bovine retinal rod cells at 2.9 ångström (A) resolution. Compared to rhodopsin, opsin shows prominent structural changes in the conserved E(D)RY and NPxxY(x)(5,6)F regions and in TM5-TM7. At the cytoplasmic side, TM6 is tilted outwards by 6-7 A, whereas the helix structure of TM5 is more elongated and close to TM6. These structural changes, some of which were attributed to an active GPCR state, reorganize the empty retinal-binding pocket to disclose two openings that may serve the entry and exit of retinal. The opsin structure sheds new light on ligand binding to GPCRs and on GPCR activation.


Assuntos
Receptores Acoplados a Proteínas G/química , Opsinas de Bastonetes/química , Animais , Sítios de Ligação , Bovinos , Sequência Conservada , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Conformação Proteica , Dobramento de Proteína , Receptores Acoplados a Proteínas G/metabolismo , Células Fotorreceptoras Retinianas Bastonetes/química , Células Fotorreceptoras Retinianas Bastonetes/citologia , Retinaldeído/química , Retinaldeído/metabolismo , Rodopsina/química , Opsinas de Bastonetes/metabolismo
12.
Nature ; 455(7212): 497-502, 2008 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-18818650

RESUMO

Opsin, the ligand-free form of the G-protein-coupled receptor rhodopsin, at low pH adopts a conformationally distinct, active G-protein-binding state known as Ops*. A synthetic peptide derived from the main binding site of the heterotrimeric G protein-the carboxy terminus of the alpha-subunit (GalphaCT)-stabilizes Ops*. Here we present the 3.2 A crystal structure of the bovine Ops*-GalphaCT peptide complex. GalphaCT binds to a site in opsin that is opened by an outward tilt of transmembrane helix (TM) 6, a pairing of TM5 and TM6, and a restructured TM7-helix 8 kink. Contacts along the inner surface of TM5 and TM6 induce an alpha-helical conformation in GalphaCT with a C-terminal reverse turn. Main-chain carbonyl groups in the reverse turn constitute the centre of a hydrogen-bonded network, which links the two receptor regions containing the conserved E(D)RY and NPxxY(x)(5,6)F motifs. On the basis of the Ops*-GalphaCT structure and known conformational changes in Galpha, we discuss signal transfer from the receptor to the G protein nucleotide-binding site.


Assuntos
Subunidades alfa de Proteínas de Ligação ao GTP/química , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Opsinas de Bastonetes/química , Opsinas de Bastonetes/metabolismo , Motivos de Aminoácidos , Animais , Arginina/química , Arginina/metabolismo , Sítios de Ligação , Bovinos , Sequência Conservada , Cristalização , Cristalografia por Raios X , Modelos Biológicos , Modelos Moleculares , Conformação Proteica , Regeneração , Retinaldeído/química , Retinaldeído/metabolismo , Rodopsina/química , Transdução de Sinais
13.
Appl Microbiol Biotechnol ; 98(19): 8179-89, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25073519

RESUMO

We present a simple, eco-friendly synthesis of silver and gold nanoparticles using a natural polymer pine gum solution as the reducing and capping agent. The pine gum solution was combined with silver nitrate (AgNO3) or a chloroauric acid (HAuCl4) solution to produce silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), respectively. The reaction process was simple; formation of the nanoparticles was achieved by autoclaving the silver and gold ions with the pine gum. UV-Vis spectra showed surface plasmon resonance (SPR) for silver and gold nanoparticles at 432 and 539 nm, respectively. The elemental forms of AgNPs and AuNPs were confirmed by energy-dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy (FTIR) showed the biomolecules present in the pine gum, AgNPs, and AuNPs. Transmission electron microscopy (TEM) images showed the shape and size of AgNPs and AuNPs. The crystalline nature of synthesized AgNPs and AuNPs was confirmed by X-ray crystallography [X-ray diffraction (XRD)]. Application of synthesized AgNPs onto cotton fabrics and leather, in order to evaluate their antibacterial properties against odor- or skin infection-causing bacteria, is also discussed. Among the four tested bacteria, AgNP-coated cotton fabric and leather samples displayed excellent antibacterial activity against Brevibacterium linens.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Nanopartículas Metálicas/química , Odorantes/prevenção & controle , Prata/farmacologia , Dermatopatias Bacterianas/veterinária , Têxteis/microbiologia , Animais , Antibacterianos/síntese química , Antibacterianos/química , Odorantes/análise , Prata/química , Pele/microbiologia , Dermatopatias Bacterianas/microbiologia , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Têxteis/análise
14.
Bioprocess Biosyst Eng ; 37(10): 1935-43, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24668029

RESUMO

In the present study, we synthesized silver and gold nanoparticles with a particle size of 10-20 nm, using Zingiber officinale root extract as a reducing and capping agent. Chloroauric acid (HAuCl4) and silver nitrate (AgNO3) were mixed with Z. officinale root extract for the production of silver (AgNPs) and gold nanoparticles (AuNPs). The surface plasmon absorbance spectra of AgNPs and AuNPs were observed at 436-531 nm, respectively. Optimum nanoparticle production was achieved at pH 8 and 9, 1 mM metal ion, a reaction temperature 50 °C and reaction time of 150-180 min for AgNPs and AuNPs, respectively. An energy-dispersive X-ray spectroscopy (SEM-EDS) study provides proof for the purity of AgNPs and AuNPs. Transmission electron microscopy images show the diameter of well-dispersed AgNPs (10-20 nm) and AuNPs (5-20 nm). The nanocrystalline phase of Ag and Au with FCC crystal structures have been confirmed by X-ray diffraction analysis. Fourier transform infrared spectroscopy analysis shows the respective peaks for the potential biomolecules in the ginger rhizome extract, which are responsible for the reduction in metal ions and synthesized AgNPs and AuNPs. In addition, the synthesized AgNPs showed a moderate antibacterial activity against bacterial food pathogens.


Assuntos
Antibacterianos/química , Ouro/química , Nanopartículas Metálicas , Extratos Vegetais/química , Raízes de Plantas/química , Prata/química , Zingiber officinale/química , Antibacterianos/farmacologia , Bacillus/efeitos dos fármacos , Listeria/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Extratos Vegetais/farmacologia , Espectrometria por Raios X , Staphylococcus/efeitos dos fármacos , Ressonância de Plasmônio de Superfície
15.
Indian J Microbiol ; 54(2): 196-202, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25320422

RESUMO

This study reveals a green process for the production of multi-morphological silver (Ag NPs) and gold (Au NPs) nanoparticles, synthesized using an agro-industrial residue cashew nut shell liquid. Aqueous solutions of Ag(+) ions for silver and chloroaurate ions for gold were treated with cashew nut shell extract for the formation of Ag and Au NPs. The nano metallic dispersions were characterized by measuring the surface plasmon absorbance at 440 and 546 nm for Ag and Au NPs. Transmission electron microscopy showed the formation of nanoparticles in the range of 5-20 nm for silver and gold with assorted morphologies such as round, triangular, spherical and irregular. Scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction analyses of the freeze-dried powder confirmed the formation of metallic Ag and Au NPs in crystalline form. Further analysis by Fourier transform infrared spectroscopy provided evidence for the presence of various biomolecules, which might be responsible for the reduction of silver and gold ions. The obtained Ag and Au NPs had significant antibacterial activity, minimum inhibitory concentration and minimum bactericidal concentration on bacteria associated with fish diseases.

16.
Trends Biochem Sci ; 34(11): 540-52, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19836958

RESUMO

G protein-coupled receptors (GPCRs) are ubiquitous signal transducers in cell membranes, as well as important drug targets. Interaction with extracellular agonists turns the seven transmembrane helix (7TM) scaffold of a GPCR into a catalyst for GDP and GTP exchange in heterotrimeric Galphabetagamma proteins. Activation of the model GPCR, rhodopsin, is triggered by photoisomerization of its retinal ligand. From the augmentation of biochemical and biophysical studies by recent high-resolution 3D structures, its activation intermediates can now be interpreted as the stepwise engagement of protein domains. Rearrangement of TM5-TM6 opens a crevice at the cytoplasmic side of the receptor into which the C terminus of the Galpha subunit can bind. The Galpha C-terminal helix is used as a transmission rod to the nucleotide binding site. The mechanism relies on dynamic interactions between conserved residues and could therefore be common to other GPCRs.


Assuntos
Proteínas Heterotriméricas de Ligação ao GTP/química , Modelos Moleculares , Receptores Acoplados a Proteínas G/química , Rodopsina/química , Animais , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Humanos , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Receptores Acoplados a Proteínas G/metabolismo , Rodopsina/metabolismo , Transdução de Sinais
17.
Chemosphere ; 361: 142554, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38851502

RESUMO

Increasing multidrug-resistant pathogenic microbial around the world become a global problem, making it imperative to develop effective methods for bacterial inactivation in wastewater. In this study, we propose a multifunctional photoelectrochemical (PEC) system to successfully disinfect microbial cells and degrade orange (II) dyes. CoOx NP were synthesized by spin-coating onto hydrothermally synthesized TiO2 nanorod arrays followed by electrodeposited NiFe-LDH to develop the NiFe-LDH/CoOx NP-TiO2 NRs. Interestingly, spin-coated CoOx NP-TiO2 NRs exhibited a 1.5-fold enhancement in photocurrent (1.384 mA/cm2) than pristine TiO2 NRs (0.92 mA/cm2). A NiFe-layered double hydroxide (LDH) cocatalysts layer further exhibits the maximum photocurrent density of 1.64 mA/cm2 with IPCE of 84.5% at 1.0 VAg/AgCl at 380 nm. Furthermore, NiFe-LDH/CoOx-TiO2 NR photoanodes were effectually employed for photoelectrochemical bacteria disinfection and organic pollutant removals. With NiFe-LDH/CoOx-TiO2 NR, 99% (120 min) bacterial inactivation and 99% (60 min) orange II dye decomposition efficiency was achieved. Superoxide radicals (-O2•), hydroxyl radicals (HO•), and holes (h+) played a critical role in the PEC degradation systems. Due to the synergy between NiFe-LDH cocatalyst and CoOx interlayer, surface water oxidation reactions were accelerated over NiFe-LDH/CoOx NP-TiO2 NRs. The charge transport process in NiFe-LDH/CoOx NP-TiO2 NRs photoanode-based PEC system was proposed in detail.


Assuntos
Eletrodos , Titânio , Águas Residuárias , Titânio/química , Águas Residuárias/química , Catálise , Técnicas Eletroquímicas/métodos , Poluentes Químicos da Água/química , Hidróxidos/química , Eliminação de Resíduos Líquidos/métodos , Processos Fotoquímicos , Nanotubos/química , Corantes/química , Compostos Azo/química , Purificação da Água/métodos , Desinfecção/métodos
18.
Chemosphere ; 360: 142450, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38801902

RESUMO

Herein, we successfully synthesized Hf/Zr co-doping on Fe2O3 nanorod photocatalyst by a hydrothermal process and quenching methods. The synergistic roles of Hf and Zr double-doping on the bacteria inactivation test and decomposition of organic pollutants were investigated in detail for the 1 wt% CoOx loaded Hf/Zr-Fe2O3 NRs and CuOx/CoOx loaded Hf/Zr-Fe2O3 NRs photocatalyst. Initially, the rod-like porous morphology of the Hf/Zr-doped Fe2O3 NRs was produced via a hydrothermal method at various Hf co-doping (0, 2, 4, 7 and 10)%. Further, CoOx and CuOx loaded by a wet impregnation approach on the Hf/Zr-Fe2O3 NRs and a highly photoactive Hf(4)/Zr-Fe2O3 [CoOx/CuOx] NRs photocatalyst were developed. After the Hf(4)/Zr-Fe2O3 [CoOx/CuOx] NRs photocatalyst treatment, the Bio-TEM imagery of bacterial cells showed extensive morphological deviations in cell membranes. Hf(4)/Zr-Fe2O3 NR achieved 84.1% orange II degradation upon 3 h illumination, which is higher than that of Hf-Fe2O3 and Zr-Fe2O3 (68.7 and 73.5%, respectively). Additionally, the optimum sample, Hf(4)/Zr-Fe2O3 [CoOx/CuOx] photocatalyst, exhibited 95.5% orange II dye degradation after light radiation for 3 h. Optimized Hf(4)/Zr-Fe2O3 [CoOx/CuOx] catalysts exhibited 99.9% and 99.7% inactivation of E. coli and S. aureus with 120 min, respectively. Further, scavenger experiments revealed that the electrons are the primary responsible species for photocatalytic kinetics. This work will provide a rapid method for the development of high photocatalytic performance materials for bacterial disinfection and organic degradation.


Assuntos
Antibacterianos , Cobre , Compostos Férricos , Nanotubos , Zircônio , Zircônio/química , Antibacterianos/química , Antibacterianos/farmacologia , Catálise , Nanotubos/química , Compostos Férricos/química , Cobre/química , Cobre/farmacologia , Háfnio/química , Óxidos/química , Cobalto/química , Processos Fotoquímicos
19.
Br J Pharmacol ; 2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38852992

RESUMO

BACKGROUND AND PURPOSE: Only limited therapeutic agents have been developed for non-alcoholic steatohepatitis (NASH). Glabridin, a promising anti-obesity candidate, has only limited druggability due to its low in vivo chemical stability and bioavailability. Therefore, we developed vutiglabridin (VUTI), which is based on a glabridin backbone, and investigated its mechanism of action in treating NASH in animal models. EXPERIMENTAL APPROACH: Anti-NASH effects of VUTI were determined in in vitro fatty liver models, spheroids of primary human hepatocytes and L02 normal liver cell lines. To identify VUTI possible cellular target/s, biotin-labelled VUTI was synthesized and underwent chemical proteomic analysis. Further, the evaluation of VUTI therapeutic efficacy was carried out using an amylin-NASH and high-fat (HF) diet-induced obese (DIO) mouse models. This was carried out using transcriptomic, lipidomic and proteomic analyses of the livers from the amylin-NASH mouse model. KEY RESULTS: VUTI treatment markedly reduces hepatic steatosis, fibrosis and inflammation by promoting lipid catabolism, activating autophagy and improving mitochondrial dysfunction, all of which are hallmarks of effective NASH treatment. The cellular target of VUTI was identified as paraoxonase 2 (PON2), a newly proposed protein target for the treatment of NASH, VUTI enhanced PON2 activity. The results using PON2 knockdown cells demonstrated that PON2 is important for VUTI- activation of autophagy, promoting mitochondrial function, decreasing oxidative stress and alleviating lipid accumulation under lipotoxic condition. CONCLUSION AND IMPLICATIONS: Our data demonstrated that VUTI is a promising therapeutic for NASH. Targeting PON2 may be important for improving liver function in various immune-metabolic diseases including NASH.

20.
J Pept Sci ; 19(8): 485-90, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23794461

RESUMO

Noxa is a key player in p53-induced cell death via mitochondrial dysfunction, and the mitochondrial-targeting domain (MTD) of Noxa is responsible for the translocation of Noxa to mitochondria and for the induction of necrotic cell death. The purpose of this study was to define the minimal killing unit of MTD in vitro and in vivo. It was found that the peptides R8:MTD(10), R8:MTD(9), and R8:MTD(8) can kill various human tumor cells (HCT116, HeLa, MCF-7, BJAB), but that R8:MTD(7) abolishes the killing activity of MTD mainly because of the loss of mitochondrial targeting activity. We find it interesting that R8:MTD(8) was found to kill tumor cells but showed a limited killing activity on normal peritoneal macrophages. Furthermore, R8:MTD(10), R8:MTD(9), and R8:MTD(8) limitedly suppressed tumor growth when injected i.v. into BalB/C mice bearing CT26 cell-derived tumors. These results indicate that MTD(8) is the minimal killing unit of MTD.


Assuntos
Antineoplásicos/farmacologia , Fragmentos de Peptídeos/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/farmacologia , Sequência de Aminoácidos , Animais , Antineoplásicos/química , Apoptose , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Transplante de Neoplasias , Fragmentos de Peptídeos/química , Sinais Direcionadores de Proteínas , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-bcl-2/química
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