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1.
J Med Cases ; 15(6): 110-114, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38855292

RESUMO

Enterobacter cloacae belongs to Enterobacter genus. It is a common gram-negative, facultative anaerobic, rod-shaped organism. It causes a variety of nosocomial infections including urinary tract infection, pneumonia, wound infection, osteomyelitis and endocarditis. Over time Enterobacter cloacae complex (ECC) has developed to be resistant to antibiotics including carbapenem. It has been rarely reported to cause gas gangrene and never been reported to cause pseudoaneurysm (PA) of transplant renal artery. We report and share our experience with this rare case of gas forming and muti-drug resistant ECC which led to mycotic PA of transplant renal artery, complicated by bleeding and infected hematoma and which resulted in graft nephrectomy.

2.
Anal Methods ; 16(24): 3993-4001, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38855887

RESUMO

A facile electrochemical approach is proposed for the synchronous determination of acetaminophen (ACP), codeine (COD) and caffeine (CAF) utilizing unmodified screen-printed electrodes (SPEs). The determination of ACP, COD and CAF has been explored across different supporting electrolytes including sulfuric acid (H2SO4), hydrochloric acid (HCl), phosphoric acid (H3PO4) and Briton Robinson (B.R) buffer solutions. It was found that a 0.05 mol L-1 sulfuric acid solution is an optimal supporting electrolyte utilized for voltammetric analysis of ACP, COD, and CAF with improved sensitivity, stability, and reproducibility. The electro-analytical sensing of ACP, COD and CAF was investigated using SPEs within linear concentration ranges of 3.0-35.0 µmol L-1, 10-160 µmol L-1 and 10-160 µmol L-1 and revealed competitively low limits of detection (3S/N) of 0.9, 4.8 and 6.3 µmol L-1 for ACP, COD and CAF, respectively. The results indicated the possibility of such a simple and quick electroanalytical protocol for online monitoring of pharmaceutical formulations comprising ACP, COD, and CAF drugs in human fluids with satisfactory recovery.


Assuntos
Acetaminofen , Cafeína , Codeína , Técnicas Eletroquímicas , Eletrodos , Grafite , Acetaminofen/análise , Acetaminofen/química , Codeína/análise , Codeína/química , Cafeína/análise , Cafeína/química , Humanos , Grafite/química , Técnicas Eletroquímicas/métodos , Limite de Detecção , Reprodutibilidade dos Testes
3.
RSC Adv ; 14(5): 3536-3547, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38259997

RESUMO

This study reports the synthesis of a mesoporous Mo and N codoped anatase TiO2 nanocomposite with many oxygen vacancies using a simple one-step hydrothermal method and subsequent calcination treatment. Both Mo and N were effectively co-incorporated into the anatase phase of TiO2 without MoOx phase segregation. The codoped catalyst demonstrated a mesoporous architecture with a surface area of 107.48 m2 g-1 and a pore volume of 0.2974 cm3 g-1. X-ray photoelectron spectroscopy confirmed that both Mo and N dissolved in the TiO2 lattice and created induced oxygen vacancies. The interaction of the dopants (Mo and N) and oxygen vacancies clearly affected TiO2 crystal formation. Photocatalytic performance of the nanocomposite was investigated in terms of the decomposition of methyl orange at a concentration of 50 mg L-1 in an aqueous solution. The results revealed a significant methyl orange degradation of up to 99.6% after 30 min irradiation under a UV light. The impressive performance of the nanocomposite is assigned to the synergetic effect of important factors, including the co-doping of metallic (Mo) and non-metallic (N) elements, oxygen vacancy defects, bandgap, crystallite size, mesoporous structure, and BET surface area.

4.
Phys Chem Chem Phys ; 26(3): 2426-2439, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38168700

RESUMO

In the pursuit of tracking some physicochemical properties of fluids down to the molecular level, ab initio molecular surface analyses were performed on 169 molecules. This included electrostatic potential (EP), average local ionization energy (ALIE), and electron localization function (ELF) mapped onto an electron density isosurface value of 0.001 au. Using stepwise linear regression (SLR) analysis, it was found that besides the well-studied EP, ALIE and ELF played important roles in determining the normal boiling and freezing points and critical temperatures of fluids. Apparently, the ALIE and ELF were relevant to the attractive polarization forces and repulsive Pauli forces, respectively, between molecules. To further demonstrate and rationalize this assumption, a localized molecular orbital energy decomposition analysis (LMO-EDA) was carried out. In the LMO-EDA analysis, the complexes of the helium atom, He, and ClCl, ClBr, ClI, OCO, OCS, OCSe, and CO/OC molecules were investigated, where the helium atom faced different molecular sites in each molecule. Fortunately, the results showed that lower the ALIE value on a molecular site, the stronger (i.e., more attractive) the polarization interaction energy. The results also indicated that higher the ELF value on a molecular site, the stronger (i.e., more repulsive) the Pauli interaction. The work is aimed to present novel molecular-based rationales to physical chemists, chemical engineers, and materials scientists.

5.
RSC Adv ; 13(36): 25081-25092, 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37622010

RESUMO

The doping of TiO2 with metals and non-metals is considered one of the most significant approaches to improve its photocatalytic efficiency. In this study, the photodegradation of methyl orange (MO) was examined in relation to the impact of Bi-doping of TiO2. The doped TiO2 with various concentrations of metal was successfully synthesized by a one-step hydrothermal method and characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and UV-vis spectroscopy. The XRD results revealed that the anatase phase, with an average crystallite size of 16.2 nm, was the main phase of TiO2. According to the anatase texture results, it was found that the doping of TiO2 increased the specific surface area for Bi2O3@TiO2 without a change in the crystal structure or the crystal phase of TiO2. Also, XPS analysis confirmed the formation of Ti4+ and Ti3+ as a result of doping with Bi. The activities of both pure TiO2 and Bi-doped TiO2 were tested to study their ability to decolorize MO dye in an aqueous solution. The photocatalytic degradation of MO over Bi2O3@TiO2 reached 98.21%, which was much higher than the 42% achieved by pure TiO2. Doping TiO2 with Bi increased its visible-light absorption as Bi-doping generated a new intermediate energy level below the CB edge of the TiO2 orbitals, causing a shift in the band gap from the UV to the visible region, thus enhancing its photocatalytic efficiency. In addition, the effects of the initial pH, initial pollutant concentration, and contact time were examined and discussed.

6.
Front Mol Biosci ; 10: 1172403, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37214337

RESUMO

Introduction: Foodborne trichothecene T-2 Toxin, is a highly toxic metabolite produced by Fusarium species contaminating animal and human food, causing multiple organ failure and health hazards. T-2 toxins induce hepatotoxicity via oxidative stress causing hepatocytes cytotoxicity and genotoxicity. In this study, curcumin and taurine were investigated and compared as antioxidants against T-2-provoked hepatotoxicity. Methods: Wistar rats were administrated T-2 toxin sublethal oral dose (0.1 mg/kg) for 2 months, followed by curcumin (80 mg/kg) and taurine (50 mg/kg) for 3 weeks. Biochemical assessment of liver enzymes, lipid profiles, thiobarbituric acid reactive substances (TBARs), AFU, TNF-α, total glutathione, molecular docking, histological and immunohistochemical markers for anti-transforming growth factor-ß1 (TGFß1), double-strand DNA damage (H2AX), regeneration (KI67) and apoptosis (Active caspase3) were done. Results and Discussion: Compared to T-2 toxin, curcumin and taurine treatment significantly ameliorated hepatoxicity as; hemoglobin, hematocrit and glutathione, hepatic glycogen, and KI-67 immune-reactive hepatocytes were significantly increased. Although, liver enzymes, inflammation, fibrosis, TGFß1 immunoexpressing and H2AX and active caspase 3 positive hepatocytes were significantly decreased. Noteworthy, curcumin's therapeutic effect was superior to taurine by histomorphometry parameters. Furthermore, molecular docking of the structural influence of curcumin and taurine on the DNA sequence showed curcumin's higher binding affinity than taurine. Conclusion: Both curcumin and taurine ameliorated T-2 induced hepatotoxicity as strong antioxidative agents with more effectiveness for curcumin.

7.
Sci Rep ; 13(1): 2065, 2023 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-36739445

RESUMO

Obelisks presented an important element in the architecture of ancient Egypt. This research is concerned with the re-erection of an obelisk that belongs to the famous Pharoah Ramses II. It was found broken and was transported to the Grand Egyptian Museum for restoration and display. An observation of Ramses II Cartouche at the bottom side of the obelisk base inspired the authorities to provide an innovative architectural design to display the obelisk elevated. The supporting structure was designed to allow the visitors to walk underneath the obelisk and observe Ramses II's signature. The idea of elevating the obelisk presented several challenges including evaluating the obelisk's current condition, restoration and fixation methodology, structural stability, and uncertainties of material characteristics, amongst others. To control the obelisk deformations under lateral loading, state-of-the-art base isolators were introduced. For the task to be achieved, a multidisciplinary team including historians, conservators, archaeologists, architects, and engineers with different specialties was appointed. The team performed the task successfully and currently, the obelisk stands at the entrance piazza of the Grand Egyptian Museum representing the world's first elevated obelisk.

8.
Comput Biol Chem ; 97: 107643, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35189479

RESUMO

The current research focuses on the treatment of Cr(III), Fe(III) and Cu(II) metal ions with aryl hydrazone ligand named (E)-4-(((diphenylmethylene)hydrazono)methyl)benzene-1,3-diol (DPHB) to afford four novel solid complexes with high yields. Different characterization approaches, including infrared, UV-visible, and NMR spectroscopies, elemental analyses, and thermal gravimetric analysis (TGA), revealed that all mononuclear crystalline metal chelates with good thermal stability had a six-coordination with octahedral geometry. Density Functional Theory (DFT) computations were used and provided a reasonable explanation for these metal chelates' electrical and structural features. Furthermore, investigations of electronic absorption spectroscopy, hydrodynamics, and electrophoresis demonstrated that these new compounds interact with calf thymus deoxyribonucleic acid (CT-DNA) in a variety of ways. As a result, the Kb and ∆Gb≠ values of such interactions were in the following order: DPHBCu > DPHBCr > DPHBFe complex. Additionally, the novel metal chelates have been studied anti-bathogenically and found to be significantly effective compared to the comparable DPHB hydrazone ligand. The anti-proliferative activities of the investigated compounds were also evaluated against different lines of cancer cells and exhibited significant cytotoxic activity. In addition, observations of antioxidant activity suggest that antioxidant activity relative to ordinary ascorbic acid was demonstrated in the molecule.


Assuntos
Compostos Férricos , Hidrazonas , DNA/química , Teoria da Densidade Funcional , Hidrazonas/farmacologia , Ligantes , Testes de Sensibilidade Microbiana
9.
Pharmaceutics ; 13(5)2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-34066092

RESUMO

The continuous loss of human life due to the paucity of effective drugs against different forms of cancer demands a better/noble therapeutic approach. One possible way could be the use of nanostructures-based treatment methods. In the current piece of work, we have synthesized silver nanoparticles (AgNPs) using plant (Heliotropiumbacciferum) extract using AgNO3 as starting materials. The size, shape, and structure of synthesized AgNPs were confirmed by various spectroscopy and microscopic techniques. The average size of biosynthesized AgNPs was found to be in the range of 15 nm. The anticancer potential of these AgNPs was evaluated by a battery of tests such as MTT, scratch, and comet assays in breast (MCF-7) and colorectal (HCT-116) cancer models. The toxicity of AgNPs towards cancer cells was confirmed by the expression pattern of apoptotic (p53, Bax, caspase-3) and antiapoptotic (BCl-2) genes by RT-PCR. The cell viability assay showed an IC50 value of 5.44 and 9.54 µg/mL for AgNPs in MCF-7 and HCT-116 cell lines respectively. We also observed cell migration inhibiting potential of AgNPs in a concentration-dependent manner in MCF-7 cell lines. A tremendous rise (150-250%) in the production of ROS was observed as a result of AgNPs treatment compared with control. Moreover, the RT-PCR results indicated the difference in expression levels of pro/antiapoptotic proteins in both cancer cells. All these results indicate that cell death observed by us is mediated by ROS production, which might have altered the cellular redox status. Collectively, we report the antimetastasis potential of biogenic synthesized AgNPs against breast and colorectal cancers. The biogenic synthesis of AgNPs seems to be a promising anticancer therapy with greater efficacy against the studied cell lines.

10.
Cell Biochem Biophys ; 79(4): 833-844, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34110566

RESUMO

Alpha-amylase (α-amylase) not long ago has acquire recognition as a possible drug target for the management of diabetes. Here, we have investigated the binding and enzyme activity of α-amylase by hesperidin; a naturally occurring flavanone having wide therapeutic potential. Hesperidin exerted an inhibitory influence on α-amylase activity with an IC50 value of 16.6 µM. Hesperidin shows a significant binding toward α-amylase with a binding constant (Ka) of the order of 104 M-1. The evaluation of thermodynamic parameters (∆H and ∆S) suggested that van der Waals force and hydrogen bonding drive seemingly specific hesperidin-α-amylase complex formation. Glycation and oxidation studies were performed using human serum albumin (HSA) as ideal protein. Hesperidin inhibited fructosamine content ≈40% at 50 µM and inhibited advanced glycation end products (AGEs) formation by 71.2% at the same concentration. Moreover, significant recovery was evident in free -SH groups and carbonyl content of HSA. Additionally, molecular docking also entrenched in vitro observations and provided an insight into the important residues (Trp58, Gln63, His101, Glu233, Asp300, and His305) at the heart of hesperidin-α-amylase interaction. This study delineates mechanistic insight of hesperidin-α-amylase interaction and provides a platform for use of hesperidin to treat AGEs directed diseases.


Assuntos
Produtos Finais de Glicação Avançada
11.
J Clin Neurol ; 17(1): 121-127, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33480207

RESUMO

BACKGROUND AND PURPOSE: Abnormal excitability of the central nervous system, both spinal and supraspinal, has previously been described as a pathophysiological plastic mechanism for chronic pain syndromes. Primary fibromyalgia (FM) as one extreme of this spectrum of diseases. This case-control study aimed to determine the changes in the spinal excitability by investigating the Hoffman reflex (H-reflex) in patients with FM. METHODS: Thirty-eight patients with FM and 30 healthy controls participated in this case-control study. We measured the H-reflex bilaterally in the upper limbs (flexor carpi radialis) and the lower limbs (gastrocnemius and soleus). Moreover, pain-related variables were measured, including pain severity (using a visual analogue scale), pain duration, Widespread Pain Index, and the score on the Symptom Severity Scale. Various psychiatric comorbidities and quality-of-life parameters were measured for each patient, including scores on the Hamilton Depression Rating Scale, Taylor's Manifest Anxiety Scale, and the Revised Fibromyalgia Impact Questionnaire. RESULTS: A significant increase in the ratio of the maximum baseline-to-peak amplitudes of H and M waves (Hmax/Mmax) but not in the H-wave minimum latency was found in patients with FM compared with healthy controls. There were no significant correlations between this ratio in both muscles and the various pain-related measures, psychiatric comorbidity, and quality of life in patients with FM. Patients with FM suffered more depression and anxiety than did the controls. CONCLUSIONS: We found increased spinal excitability in patients with FM, which was not confined to the site of maximum pain. This information may help in the diagnosis of FM and supports the hypothesis of central sensitization.

12.
Arch Pharm (Weinheim) ; 354(4): e2000241, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33336849

RESUMO

A new bidentate Schiff base ligand (ATBS [4-bromo-2-(thiazole-2-yliminomethyl)phenol]) was synthesized via the condensation reaction of 2-aminothiazole with 5-bromosalicylaldehyde in ethanol. The reaction of ATBS with transition metal salts of Cu(II), Co(II), Ni(II), and Mn(II) afforded the corresponding ATBS-M complexes. Results from physicochemical and spectral analyses, such as elemental analysis, infrared, UV-Vis spectroscopy, magnetic susceptibility, and molar conductance, revealed a nonelectrolytic nature with octahedral (Oh ) geometry and a metal/ligand ratio of 1:2 for Cu(II), Co(II), and Ni(II), but 1:1 for the Mn(II) complex. The density functional theory (DFT) calculations are correlated very well with the proposed structure and molecular geometry of the complexes as [M(ATBS)2 ] (M = Cu, Co, and Ni) and [Mn(ATBS)(H2 O)2 ]. Significantly, the prepared compounds showed strong inhibition activity for a wide spectrum of bacteria (Escherichia coli, Bacillus subtilis, and Staphylococcus aureus) and fungi (Candida albicans, Aspergillus flavus, and Trichophyton rubrum), with the ATBS-Ni complex being the most promising antibiotic agent. Molecular docking studies of the binding interaction between the title complexes with the bacterial protein receptor CYP51 revealed clear insights about the inhibition nature against the studied microorganisms, with the following order: ATBS-Cu > ATBS-Mn > ATBS-Ni > ATBS-Co for complex stability. Moreover, the cytotoxicity measurements of all prepared metal complexes against the colon carcinoma (HCT-116) and hepatocellular carcinoma (Hep-G2) cell lines showed exceptional anticancer efficacy of the complexes as compared with the free ATBS Schiff base ligand. Significantly, the results attested that ATBS-Cu is the most effective complex against HCT-116 cells, whereas ATBS-Mn has the highest cytotoxic efficiency against Hep-G2 cells. Furthermore, electronic spectra, viscosity measurements, and gel electrophoresis techniques were employed to probe the interaction of all prepared ATBS-metal complexes with calf thymus (CT)-DNA. Results confirmed that all complexes are strongly bound to CT-DNA via intercalation mode, with the ATBS-Co complex having the highest binding ability.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Metais Pesados/farmacologia , Bases de Schiff/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Bactérias/efeitos dos fármacos , Bovinos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Teoria da Densidade Funcional , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Fungos/efeitos dos fármacos , Humanos , Ligantes , Metais Pesados/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Bases de Schiff/química , Soroalbumina Bovina/química , Relação Estrutura-Atividade , Viscosidade
13.
RSC Adv ; 11(43): 26710-26720, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35479994

RESUMO

Lactoferrin is a heme-binding multifunctional glycoprotein known for iron transportation in the blood and also contributes to innate immunity. In this study, the interaction of theaflavin monogallate, a polyphenolic component of black tea, with camel milk lactoferrin was studied using various biophysical and computational techniques. Fluorescence quenching at different temperatures suggests that theaflavin monogallate interacted with lactoferrin by forming a non-fluorescent complex, i.e., static quenching. Theaflavin monogallate shows a significant affinity towards lactoferrin with a binding constant of ∼104-105 M-1 at different temperatures. ANS binding shows that the binding of polyphenol resulted in the burial of hydrophobic domains of lactoferrin. Moreover, thermodynamic parameters (ΔH, ΔS and ΔG) suggested that the interaction between protein and polyphenol was entropically favored and spontaneous. Circular dichroism confirmed there was no alteration in the secondary structure of lactoferrin. The energy transfer efficiency (FRET) from lactoferrin to theaflavin was found to be approximately 50%, with a distance between protein and polyphenol of 2.44 nm. Molecular docking shows that the binding energy of lactoferrin-theaflavin monogallate interaction was -9.7 kcal mol-1. Theaflavin monogallate was bound at the central cavity of lactoferrin and formed hydrogen bonds with Gln89, Tyr192, Lys301, Ser303, Gln87, and Val250 of lactoferrin. Other residues, such as Tyr82, Tyr92, and Tyr192, were involved in hydrophobic interactions. The calculation of various molecular dynamics simulations parameters indicated the formation of a stable complex between protein and polyphenol. This study delineates the binding mechanism of polyphenol with milk protein and could be helpful in milk formulations and play a key role in the food industry.

14.
Eur. J. Ost. Clin. Rel. Res ; 14(1): 8-16, ene.-dic. 2019. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-196409

RESUMO

INTRODUCCIÓN: La fibromialgia es una enfermedad caracterizada por dolor musculoesquelético difuso generalizado. Su etiología permanece desconocida, por lo que el tratamiento se enfoca a nivel sintomático. Actualmente son de especial interés los tratamientos no farmacológicos. La osteopatía es un sistema de tratamiento no farmacológico que pone el énfasis principal sobre la integridad estructural del cuerpo interconectando los diferentes sistemas que pueden repercutir sobre la patología. OBJETIVOS: Comprobar la efectividad del tratamiento osteopático sobre el dolor y otros síntomas en enfermos de fibromialgia, además de concretar sobre cuál de estos síntomas presentan mayor efecto y cuáles de las diferentes técnicas osteopáticas presenta mayor evidencia para su aplicación en estos pacientes. MATERIAL Y MÉTODOS: Se revisaron en las bases de datos PubMed,CENTRAL, Google Scholar, PEDro, Scielo, y Osteopathic Research Web, la bibliografía existente sobre la aplicación de técnicas osteopáticas en sus diferentes abordajes: liberación miofascial, manipulación osteopática, técnicas craneosacras, técnicas funcionales, rolfing, o creeping, entre otras. Se incluyeron ensayos clínicos aleatorizados que aplicaran alguna de las diferentes técnicas propias de la osteopatía, y fueran publicados en inglés, francés, italiano, portugués o español, entre 2004 y la actualidad. Fueron excluidos los estudios cuya puntuación según la escala PEDro fuera menor de 5 puntos, los que la intervención se contemplara como tratamiento quiropráctico o como parte de otra técnica no osteopática, y los que incluyeran pacientes menores de 16 años. RESULTADOS: Se seleccionan siete artículos que reúnen las características necesarias para nuestra revisión, sumando un total 519 pacientes, todos de entre 18 y 65 años. Todos los pacientes presentaron mejoras en la percepción de dolor. CONCLUSIONES: El abordaje osteopático de la fibromialgia, desde sus diferentes técnicas, ofrece beneficios sobre algunos de los síntomas de la fibromialgia, en especial sobre el dolor, siendo la liberación miofascial la técnica con más evidencia publicada


No disponible


Assuntos
Humanos , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Osteopatia/métodos , Fibromialgia/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Medicina Baseada em Evidências , Resultado do Tratamento
15.
Int J Biol Macromol ; 88: 313-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27044344

RESUMO

The Arabian camel, Camelus dromedarius is naturally adapted to extreme desert climate and has evolved protective mechanisms to limit oxidative stress. The mitochondrial kappa class glutathione transferase enzyme is a member of GST supergene family that represents an important enzyme group in cellular Phase II detoxification machinery and is involved in the protection against oxidative stress and xenobiotics. In the present study, C. dromedarius kappa class glutathione transferase (CdGSTK1-1) was cloned, expressed in E. coli BL21, purified and its structural, thermodynamic and unfolding pathway was investigated. The results showed that CdGSTK1-1 has unique trimeric structure, exhibits low thermostability and a complex equilibrium unfolding profile. It unfolds through three folding states with formation of thinly populated intermediate species. The melting points (Tm) of the first unfolding transition was 40.3±0.2°C and Tm of the second unfolding transition was 49.1±0.1°C. The van't Hoff enthalpy of the first and second transition were 298.7±13.2 and 616.5±2.4kJ/mol, respectively. Moreover, intrinsic fluorescence and near-UV CD studies indicates that substrate binding does not leads to major conformational changes in CdGSTK1-1.


Assuntos
Camelus/metabolismo , Glutationa Transferase/química , Adaptação Fisiológica , Animais , Clonagem Molecular , Clima Desértico , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Glutationa Transferase/genética , Temperatura Alta , Isoenzimas/química , Isoenzimas/genética , Dobramento de Proteína , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Desdobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Termodinâmica
16.
Biol Trace Elem Res ; 169(1): 69-76, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26043917

RESUMO

Glutathione S-transferases (GSTs) are multifunctional enzymes and play an important role in detoxification of xenobiotics and protection against oxidative stress. Camel liver glutathione transferase (cGST) was recently isolated and characterized in our lab. In this study, we have evaluated the effect of monovalent, divalent, and trivalent cations on its activity and stability. Cu(++) was found to be the potent inhibitor of GST activity which loses complete activity at 0.5-mM concentration. Other metal ions did not inhibit GST even at higher concentration of 2 mM. GST incubated with Cu(++) (0.1 mM) resulted decrease in free sulfhydryl groups by 55%, whereas other metal ions did not show any effect on free thiol content. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed formation of GST aggregates instantly in the presence of Cu(++), which further increased in molecular size with increase in time of incubation. DTT treatment resulted in de-aggregation of GST oligomers to its monomeric form. However, the GST activity was not recovered completely after de-aggregation. Cu(++) was found to inhibit GST activity by accelerating the inter- and intra-disulfide bond formation. Far-UV circular dichroism (CD) results showed that Cu(++)-catalyzed air oxidation of sulfhydryl groups leads to minor conformational changes in the GST.


Assuntos
Cobre/farmacologia , Glutationa Transferase/metabolismo , Fígado/enzimologia , Animais , Camelus , Ativação Enzimática/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
17.
Prep Biochem Biotechnol ; 45(7): 650-66, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25036813

RESUMO

Glutathione S-transferases (GSTs) are multifunctional enzymes and play an important role in cellular detoxification. Besides this, GSTs act as cytosolic carrier proteins that bind hydrophobic compounds such as heme, bilirubin, steroids, and polycyclic hydrocarbons. GST has great importance in biotechnology, as it is a target for vaccine and drug development and biosensors development for xenobiotics. Moreover, the GST tag has been extensively used for protein expression and purification. Until now, biophysical properties of camel liver GST have not been characterized. In the present study we have purified camel (Camelus dromedarius) liver GST to homogeneity in a single step by affinity chromatography with 23.4-fold purification and 60.6% yield. Our results showed that maximal activity of GST was at pH 6.5 and it was stable in the pH range of 5 to 10. The optimum temperature was 55°C and the Tm was 57°C. The chemical chaperone glycerol (3.3 M) was able to protect GST activity and aggregation against thermal denaturation by stabilizing the protein structure at 50 and 57°C, respectively. However, L-arginine (125 mM) did not protect GST against thermal stress. Far-ultraviolet circular dichroism (CD) spectra showed that glycerol protected the secondary structure of GST while L-arginine induced conformational changes under thermal stress. In conclusion, our studies on the GST stability suggest that glycerol works as a stabilizer and L-arginine acts as a destabilizer.


Assuntos
Citosol/enzimologia , Glutationa Transferase/química , Fígado/enzimologia , Animais , Camelus , Cromatografia de Afinidade , Dicroísmo Circular , Citosol/química , Glutationa Transferase/isolamento & purificação , Fígado/química
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 117: 366-78, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24001978

RESUMO

In recent years, great interest has been focused on Fe(II) Schiff base amino acid complexes as cytotoxic and antitumor drugs. Thus a series of new iron(II) complexes based on Schiff bases amino acids ligands have been designed and synthesized from condensation of 5-bromosalicylaldehyde (bs) and α-amino acids (L-alanine (ala), L-phenylalanine (phala), L-aspartic acid (aspa), L-histidine (his) and L-arginine (arg)). The structure of the investigated iron(II) complexes was elucidated using elemental analyses, infrared, ultraviolet-visible, thermogravimetric analysis, as well as conductivity and magnetic susceptibility measurements. Moreover, the stoichiometry and the stability constants of the prepared complexes have been determined spectrophotometrically. The results suggest that 5-bromosalicylaldehyde amino acid Schiff bases (bs:aa) behave as dibasic tridentate ONO ligands and coordinate to Fe(II) in octahedral geometry according to the general formula [Fe(bs:aa)2]·nH2O. The conductivity values between 37 and 64 ohm(-1) mol(-1) cm(2) in ethanol imply the presence of nonelectrolyte species. The structure of the complexes was validated using quantum mechanics calculations based on accurate DFT methods. Geometry optimization of the Fe-Schiff base amino acid complexes showed that all complexes had octahedral coordination. In addition, the interaction of these complexes with (CT-DNA) was investigated at pH=7.2, by using UV-vis absorption, viscosity and agarose gel electrophoresis measurements. Results indicated that the investigated complexes strongly bind to calf thymus DNA via intercalative mode and showed a different DNA binding according to the sequence: bsari>bshi>bsali>bsasi>bsphali. Moreover, the prepared compounds are screened for their in vitro antibacterial and antifungal activity against three types of bacteria, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus and three types of anti fungal cultures, Penicillium purpurogenium, Aspergillus flavus and Trichotheium rosium. The results of these studies indicated that the metal complexes exhibit a stronger antibacterial and antifungal efficiency than their corresponding Schiff base amino acid ligands.


Assuntos
Aminoácidos/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Complexos de Coordenação/química , DNA/metabolismo , Compostos Ferrosos/química , Salicilatos/química , Animais , Bactérias/efeitos dos fármacos , Bovinos , Quelantes/química , Quelantes/farmacologia , Complexos de Coordenação/farmacologia , Eletroforese em Gel de Ágar , Fungos/efeitos dos fármacos , Técnicas In Vitro , Modelos Moleculares , Estrutura Molecular , Bases de Schiff/química , Espectrofotometria Infravermelho
19.
Chem Commun (Camb) ; 48(88): 10832-4, 2012 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-23014515

RESUMO

Nanomagnet-selective supercaptors of heme-proteins (iron-porphyrin prosthetic group) based on mesoporous NiO and Fe(3)O(4) NPs were fabricated.


Assuntos
Eritrócitos/química , Hemeproteínas/química , Nanopartículas de Magnetita/química , Níquel/química , Adsorção , Humanos , Insulina/química , Miosinas/química , alfa-Amilases/química
20.
J Hazard Mater ; 201-202: 23-32, 2012 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-22169140

RESUMO

Water treatment for the removal of organic or inorganic pollutants has become a serious global issue because of the increasing demand for public health awareness and environmental quality. The current paper, reports the applicability of mesoporous aluminosilica monoliths with three-dimensional structures and aluminum contents with 19≤Si/Al≥1 as effective adsorbents of organic molecules from an aqueous solution. Mesocage cubic Pm3n aluminosilica monoliths were successfully fabricated using a simple, reproducible, and direct synthesis. The acidity of the monoliths significantly increased with increasing amounts of aluminum species in the silica pore framework walls. The batch adsorption of the organic pollutants onto (10 g/L) aluminosilica monoliths was performed in an aqueous solution at various temperatures. These adsorbents exhibit efficient removal of organic pollutants (e.g., aniline, p-chloroaniline, o-aminophenol, and p-nitroaniline) of up to 90% within a short period (in the order of minutes). In terms of proximity adsorption, the functional acid sites and the condensed and rigid monoliths with tunable periodic scaffolds of the cubic mesocages are useful in providing easy-to-use removal assays for organic compounds and reusable adsorbents without any mesostructural damage, even under chemical treatment for a number of repeated cycles.


Assuntos
Silicatos de Alumínio/química , Compostos Orgânicos/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Silicatos de Alumínio/síntese química , Microscopia Eletrônica de Transmissão , Modelos Químicos , Porosidade , Propriedades de Superfície
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