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1.
Mikrochim Acta ; 189(12): 472, 2022 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-36434394

RESUMO

A label-free and specific FRET-based interleukin-6 (IL-6) aptasensor was developed using a DNA aptamer modified with nitrogen-doped carbon quantum dots (NCDs) and gold nanoparticles (AuNPs) as a donor-quencher pair. The assayed target was capable of disrupting the donor-acceptor assemblies yielding a concentration-related fluorescence recovery of NCDs (λem = 445 nm and λex = 350 nm). By designing two different probes, the interaction of DNA aptamers with IL-6 protein was studied using FRET efficiency. It appeared that the sensing probes showed slightly different sensing profiles. One of the aptasensors showed a linear response of 1.5-5.9 pg/mL for IL-6 with a coefficient of determination of R2 ≥ 0.99 and the a detection limit of 0.82 pg/mL (at S/N = 3). The experimental results indicated that the biosensor can be applied to determine IL-6 in human serum (with recovery of 95.7-102.9%). Due to the high sensitivity, excellent selectivity, and simplicity of the procedure, this strategy represents a promising alternative for IL-6 sensing in clinical applications.


Assuntos
Aptâmeros de Nucleotídeos , COVID-19 , Nanopartículas Metálicas , Pontos Quânticos , Humanos , Ouro , Interleucina-6 , Carbono , Nitrogênio , Transferência Ressonante de Energia de Fluorescência/métodos , Biomarcadores
2.
Mikrochim Acta ; 189(9): 326, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35948696

RESUMO

In a new approach, we considered the special affinity between Ni and poly-histidine tags of recombinant urate oxidase to utilize Ni-MOF for immobilizing the enzyme. In this study, a carbon paste electrode (CPE) was modified by histidine-tailed urate oxidase (H-UOX) and nickel-metal-organic framework (Ni-MOF) to construct H-UOX/Ni-MOF/CPE, which is a rapid, sensitive, and simple electrochemical biosensor for UA detection. The use of carboxy-terminal histidine-tailed urate oxidase in the construction of the electrode allows the urate oxidase enzyme to be positioned correctly in the electrode. This, in turn, enhances the efficiency of the biosensor. Characterization was carried out by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), and field emission scanning electron microscopy (FE-SEM). At optimum conditions, the biosensor provided a short response time, linear response within 0.3-10 µM and 10-140 µM for UA with a detection limit of 0.084 µM, repeatability of 3.06%, and reproducibility of 4.9%. Furthermore, the biosensor revealed acceptable stability and selectivity of UA detection in the presence of the commonly coexisted ascorbic acid, dopamine, L-cysteine, urea, and glucose. The detection potential was at 0.4 V vs. Ag/AgCl.


Assuntos
Técnicas Biossensoriais , Urato Oxidase , Técnicas Biossensoriais/métodos , Carbono/química , Eletrodos , Enzimas Imobilizadas/química , Histidina , Reprodutibilidade dos Testes , Urato Oxidase/química , Ácido Úrico
3.
Mikrochim Acta ; 189(2): 69, 2022 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-35066672

RESUMO

An annexin V-based probe is designed and fabricated using carbon quantum dot as highly stable and biocompatible fluorescent crystals for real-time fluorescence imaging of apoptotic cells. Carbon quantum dots were synthesized, characterized, and conjugated to annexin V. The fluorescence of CQDs at 450 nm (excitation at 350 nm) is quenched due to the photoinduced electron transfer between "carbon quantum dots" and two amino acids (tyrosine and tryptophan) in the annexin structure as quencher. The probe shows very strong and bright fluorescence emission in the presence of phosphatidylserine on the outer layer of the apoptotic cell membrane. It was shown that using fluorescence spectroscopy, the probe can be applied to sensitive phosphatidylserine determination and using fluorescence microscopy, it is possible to monitor cell apoptosis in real time.


Assuntos
Anexina A5/química , Apoptose/fisiologia , Carbono/química , Fosfatidilserinas/química , Pontos Quânticos/química , Aminoácidos/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Transporte de Elétrons , Humanos , Células MCF-7 , Análise de Célula Única
4.
Biochem Biophys Res Commun ; 534: 980-987, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33131770

RESUMO

Virosomes as membranous vesicles with viral fusion protein in their membrane are versatile vehicles for cargo delivery. The vesicular stomatitis virus glycoprotein (VSV-G) is a common fusogenic protein used in virosome preparation. This glycoprotein has been used in liposomal systems so far, but in this study, we have tried to use the niosomal form instead of liposome for. Niosomes are vesicular systems composed of non-ionic surfactants. Niosomes were constructed by the thin-film hydration method. VSV-G gene in pMD2.G plasmid was expressed in the HEK293T cell line and then was reconstituted in the niosome bilayer. The formation of niosomal virosomes was confirmed with different methods such as SDS-PAGE gel, western blotting, and transmission electron microscopy (TEM). The efficiency of niosomal virosome was investigated with the pmCherry reporter gene. SDS-PAGE and western blotting proved the expression and successful insertion of protein into the bilayer. The TEM images showed the spike projection of VSV-G on the surface of niosomes. The transfection results showed high efficiency of niosomal virosomes as a novel carrier. This report has verified that niosome could be used as an efficient bilayer instead of liposome to construct virosomes.


Assuntos
Técnicas de Transferência de Genes , Genes Reporter , Glicoproteínas/genética , Vesiculovirus/genética , Proteínas Virais/genética , Virossomos/genética , Expressão Gênica , Glicoproteínas/química , Células HEK293 , Humanos , Lipossomos/química , Plasmídeos/administração & dosagem , Plasmídeos/genética , Transfecção , Estomatite Vesicular/virologia , Vesiculovirus/química , Proteínas Virais/química , Virossomos/química
5.
Mol Biol Rep ; 47(2): 843-853, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31848915

RESUMO

The goal of this survey is to evaluate the anti-proliferative effects of the hydroalcholic extract of Blepharis persica seeds and its synergic effect on doxorubicin (DOX) in human colon cancer (HT-29) and gastric cancer cell (AGS) lines. 70% Ethanol was used for extraction of B. persica seed. Aluminum-chloride colorimetric and Folin-Ciocalteu reagent methods were used to measure total flavonoid and total phenolic contents of the extract respectively. Gas chromatography-mass spectrometry (GC-MS) analysis of the B. persica extract was performed on GC-MS equipment after silylation. HT-29, AGS, and human fibroblast (SKM) cell lines were treated by different concentration of the B. persica extract, (DOX) and the combination of extraction and DOX. The cytotoxicity was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay while the apoptosis induction was monitored using flowcytometry by annexin-V FITC/PI double-staining. The changes in expression levels of BAX and BCL-2 were determined using Real-Time RT-qPCR. GC-MS analysis of the hydroalcoholic extract from B. persica seeds revealed 24 major components. The MTT assay revealed the cytotoxicity against three cell lines and also it was shown that 125 ng/mL of DOX and 0.625 mg/mL of B. persica extract had synergistic behavior against HT29 cell line. These results showed B. persica extract induced apoptosis in AGS and HT29 cells and its extract caused dose-dependent increase in up-regulation of BAX level (p < 0.05) and down-regulation of BCL2 (p < 0.05). B. persica showed the synergistic effect in combination with DOX on HT29 cell line. These findings demonstrated a basis for further studies on the characterization and mechanistic evaluation of the bioactive compounds of B. persica extract which had antiproliferative effects on cancer cell lines.


Assuntos
Acanthaceae/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Extratos Vegetais/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Doxorrubicina/farmacologia , Sinergismo Farmacológico , Células HT29/efeitos dos fármacos , Humanos , Sementes/metabolismo , Neoplasias Gástricas/metabolismo
6.
Arch Biochem Biophys ; 661: 178-186, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30472239

RESUMO

The most important mode of enzyme inactivation is thermal inactivation. Immobilization technology is an efficient approach to elongate the life-time of enzymes. d-lactate dehydrogenase (D-LDH) was stabilized at high temperatures with immobilization on CNT and fCNT. The kinetic and thermodynamic parameters, optimum temperature and pH, and the intrinsic fluorescence of free and immobilized enzymes were examined in the present study. Also, an attempt was made to investigate the effect of CNT and fCNT on the adsorption and conformation of d-lactate dehydrogenase using molecular dynamics (MD) simulations. In comparison with free enzyme, the immobilized enzyme displayed an improved stability at high temperatures and, therefore, the immobilized enzyme is suitable for use in the industry because most reactions in the industry happen at high temperatures. Results of the present study showed that the adsorption of enzyme on CNT is mediated through the van der Waals and π-π stacking interactions, whereas in the adsorption of enzyme on fCNT in addition to hydrophobic interactions, the hydrogen bonding between enzyme and functional groups of fCNT is involved. Moreover, RMSD, RMSF and secondary structure analysis indicate that the fCNT protects the conformation of enzyme more than CNT. Therefore, D-LDH can be efficiently immobilized upon the fCNT compared to the pristine CNT.


Assuntos
Enzimas Imobilizadas/química , Lactato Desidrogenases/química , Simulação de Dinâmica Molecular , Nanotubos de Carbono/química , Adsorção , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Temperatura Alta , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Lactato Desidrogenases/metabolismo , Estrutura Secundária de Proteína , Solventes/química , Termodinâmica
7.
J Cell Biochem ; 119(8): 6470-6481, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29345338

RESUMO

Long non-coding RNAs are known as key regulators in the progression and metastasis of breast cancer. MIAT originally has been considered as an lncRNA to be associated with a susceptibility to myocardial infarction. Here, we have detected the expression of MIAT in different cancer cells and a series of breast tumor tissue. MIAT expression was much higher in high-grade tumors compared to low-grade ones. Unlike P53 positive tumors, MIAT expression was upregulated in ER, PR, Her2 positive tumor tissues. Knockdown MIAT suppressed breast cancer cell proliferation and caused G1 arrest in cell cycle. Furthermore, downregulation of MIAT promoted apoptosis and significantly decreased migration of breast cancer cells. An increase in the expression of mir-302, mir-150, and a decrease in the expression of mir-29c were detected following MIAT silencing. More importantly, knockdown MIAT significantly elevated the expression of p16Ink4A and Cox2, which commitment cellular senescence in breast cancer cells. Altogether, our results suggest that MIAT involved in breast cancer progression and could be candidate as a novel tumor marker for diagnosis and treatment of breast cancer.


Assuntos
Neoplasias da Mama/metabolismo , Senescência Celular , Pontos de Checagem da Fase G1 do Ciclo Celular , Regulação Neoplásica da Expressão Gênica , RNA Longo não Codificante/biossíntese , RNA Neoplásico/biossíntese , Adulto , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Inibidor p16 de Quinase Dependente de Ciclina/genética , Ciclo-Oxigenase 2/biossíntese , Ciclo-Oxigenase 2/genética , Feminino , Humanos , Células MCF-7 , Pessoa de Meia-Idade , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , RNA Longo não Codificante/genética , RNA Neoplásico/genética
8.
Mikrochim Acta ; 185(3): 165, 2018 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-29594654

RESUMO

An aptamer based method is presented for the voltammetric determination of human tumor necrosis factor alpha (TNF-α). Layers of gold hexacyanoferrate (AuHCF) and gold nanoparticles (AuNPs) were directly immobilized on a graphite screen-printed electrode (SPE). Through the strong interaction between cyanide ions (CN-) of AuHCF and AuNPs, gold nanoparticles are assembled on the modified SPE, and this allows for the covalent immobilization of thiolated aptamers against TNF-α (TNF-α-Apt). On incubation of the aptasensor with of TNF-α, the Apt/TNF-α complex is formed, and this leads to a hindered electron transfer and to a decrease in the peak current of the redox probe. Under optimum conditions and at a typical working as low as 0.1 V (vs. a silver pseudo electrode), the electrode works in the 10 pg.mL-1 to 40 µg.mL-1 TNF-α concentration range, with a 5.5 pg.mL-1 detection limit. The high sensitivity and wide detection range of this method allowed TNF-α to in human serum be detected even at very low concentrations. Graphical abstract Schematic diagram for fabrication of aptasensor: (a,b) formation of AuHCF film by electrodeposition;


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Ferrocianetos/química , Nanopartículas Metálicas/química , Fator de Necrose Tumoral alfa/sangue , Sequência de Bases , Eletrodos , Ouro/química , Grafite/química , Humanos , Limite de Detecção , Fator de Necrose Tumoral alfa/química
9.
Exp Appl Acarol ; 74(4): 365-381, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29524004

RESUMO

The two-spotted spider mite, Tetranychus uticae Koch (Acari: Tetranychidae), is globally one of the most devastating pests that feed on numerous crops, including common bean (Phaseolus vulgaris L.). This study was aimed to evaluate the effects of genotype and morphological attributes of common bean on T. uticae. Forty common bean accessions were used to investigate antixenosis and antibiosis through assessing mite feeding preference and reproduction under laboratory conditions. Three resistant (i.e., 56, 63, 238) and two susceptible (i.e., 182, 236) accessions, along with cultivars Naz (resistant) and Akhtar (susceptible), were used in a life-table study. Both antixenosis and antibiosis mechanism were observed in all of the accessions, albeit a negative correlation occurred. Significant differences were observed for all traits of T. urticae: developmental time of immature stages, reproduction, adult longevity and life-table parameters. Based on the intrinsic rate of increase, the accessions 56, 63, 182, 238, and cv. Naz impose high antibiotic effects on T. urticae. Although significant variation existed among accessions for morphological factors, only glandular trichomes correlated with mite fecundity and feeding preference.


Assuntos
Antibiose , Herbivoria , Phaseolus/anatomia & histologia , Phaseolus/fisiologia , Tetranychidae/fisiologia , Animais , Feminino , Estômatos de Plantas/anatomia & histologia , Tricomas/anatomia & histologia
10.
Anal Biochem ; 516: 1-5, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27717857

RESUMO

An immunoassay method based on the peak shift of the localized surface plasmon resonance (LSPR) absorption maxima has been developed for the determination of the thyroid stimulating hormone (TSH) in human blood serum. The anti-TSH antibody was adsorbed on the synthesized gold nanoparticles by electrostatic forces. The efficiency of the nanobiosensor was improved by optimizing the factors affecting the probe construction such as the pH and the antibody to gold nanoparticles ratio. Dynamic light scattering was applied for the characterization of the constructed probe. The amount of peak shift of the LSPR absorption maxima was selected as the basis for determination of TSH antigen. The linear dynamic range of 0.4-12.5 mIU L-1 and the calibration sensitivity of 1.71 L mIU-1 were obtained. The human control serum sample was analyzed for TSH by constructed nanobiosensor and the acceptable results were obtained.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Ressonância de Plasmônio de Superfície/métodos , Tireotropina/sangue , Humanos
11.
Anal Biochem ; 495: 32-6, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26706803

RESUMO

A localized surface plasmon resonance immunoassay has been developed to determine prolactin hormone in human serum samples. Gold nanoparticles were synthesized, and the probe was prepared by electrostatic adsorption of antibody on the surfaces of gold nanoparticles. The pH and the antibody-to-gold nanoparticle ratio, as the factors affecting the probe functions, were optimized. The constructed nanobiosensor was characterized by dynamic light scattering. The sensor was applied for the determination of prolactin antigen concentration based on the amount of localized surface plasmon resonance peak shift. A linear dynamic range of 1-40 ng ml(-1), a detection limit of 0.8 ng ml(-1), and sensitivity of 10 pg ml(-1) were obtained. Finally, the nanobiosensor was applied for the determination of prolactin in human control serum sample.


Assuntos
Técnicas Biossensoriais/instrumentação , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Ouro/química , Imunoensaio/instrumentação , Nanopartículas Metálicas/química , Prolactina/sangue , Anticorpos/química , Difusão Dinâmica da Luz , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Ressonância de Plasmônio de Superfície
12.
Protein Expr Purif ; 118: 25-30, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26431799

RESUMO

Hydrophobins are small secreted proteins belong to filamentous fungi. These proteins possess a unique ability to self-assemble at air/water interfaces. Hydrophobins have a broad range of biotechnological applications such as stabilizing emulsions and foams, immobilizing proteins on a surface, designing biosensors, affinity tag for protein purification, and drug delivery. We have successfully expressed HFB1 from Trichoderma reesei belonged to class II of hydrophobins in Pichia pastoris. The recombinant gene was under the control of the methanol-inducible AOX1 promoter (alcohol oxidase 1) in the pPICZAα vector. The amount of secreted HFB1 was increased in 90-h using methanol induction. The recombinant HFB1 was purified based on the presence of His-tag and foam formation. Furthermore, HFB1 was able to produce macro and micro stable air bubbles in the liquid due to the presence of hydrophobic patches on its surface. The liquid medium containing HFB1 becomes turbid after shaking, and then the stable bubbles are formed and remained for three weeks.


Assuntos
Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Tensoativos/química , Trichoderma/genética , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/metabolismo , Expressão Gênica , Interações Hidrofóbicas e Hidrofílicas , Pichia/genética , Pichia/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Tensoativos/isolamento & purificação , Tensoativos/metabolismo
13.
J Fluoresc ; 26(4): 1505-10, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27324950

RESUMO

The focus of this work is introduction of GelRed (GR) as a stable, sensitive and environmentally safe fluorescent DNA dye instead of the highly toxic ethidium bromide (EB). Competitive DNA-binding studies between metal complexes, [Cu(phen-dion)(phen)Cl]Cl (1), [Cu(phen-dione)(bpy)Cl]Cl (2), [Cu(dppt)2(H2O)]PF6 (3), [Ni(dppt)2Cl2] (4), [Zn(dppt)2Cl2] (5), and K3[Fe(CN)6] (6) (where phen-dione is 1,10-phenanthroline-5,6-dione, phen is 1,10- phenanthroline, bpy is 2,2'-bipyridine, and dppt is 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine), and GelRed have been investigated under physiological conditions by fluorescence spectroscopy. This simple method can reveal the binding affinity and mode of metal complexes with DNA. The method is based on the decrease of fluorescence derived from the displacement of GelRed from DNA by metal complexes. The % fluorescence decrease is directly related to the extent of DNA binding. Results indicate the DNA binding affinities of complexes follow the order 3 > 4 > 1 > 2 > 5 > 6. The significant quenching of the emission band of the GR-DNA with the addition of complexes 1, 3, and 4 suggests that complexes compete for DNA-binding sites with GR and displace GR from the GR-DNA, which is usually characteristic of the intercalative interaction of compounds with DNA. A small quenching of the emission band of the GR-DNA with the addition of the complex 2 was observed that show the complex weaker competes for DNA-binding sites with GR than complexes 1, 3, and 4. Results show complexes 5 and 6 cannot compete for DNA-binding sites with GR and their interaction with DNA is external binding (groove or electrostatic bindig).


Assuntos
Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , DNA/metabolismo , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Segurança , Fenantrolinas/química
14.
J Fluoresc ; 26(2): 545-58, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26687119

RESUMO

The focus of the present work is the preparation of new metal-based nanodrug to overcome limitations of chemotherapy such as poor water solubility of most common chemotherapeutic drugs. The copper(II) complex of 1,2,4-triazine derivatives, [Cu(dppt)2(H2O)2](2+) (dppt is 5,6-diphenyl- 3- (2-pyridyl)-1,2,4-triazine), has been synthesized at nano-size by sonochemical method and characterized by FTIR, zetasizer, and scanning electron microscopy (SEM). The interaction of the complex and nanocomplex with fish sperm DNA (FS-DNA) and BSA have been investigated under physiological conditions by a series of experimental methods. The results have indicated that the complex binds to FS-DNA by two biding modes, viz., electrostatic and intercalates into the base pairs of DNA. The competitive study with ethidium bromide (EB) shows that the complex and nanocomplex competes for the DNA-binding sites with EB. Protein binding studies show that the complex and nanocomplex could bind with BSA. The results of synchronous fluorescence of BSA show that additions of the complex affect the microenvironment of both tyrosine and tryptophan residues during the binding process. The in vitro cytotoxicity of the complex (solution in DMSO) and nanocomplex (colloid in H2O) against the human carcinoma cell lines (MCF-7 and A-549) was evaluated by MTT assay. The results of in vitro cytotoxicity indicate that the complex and nanocomplex have excellent cytotoxicity activity against MCF-7 and A-549. Results of the microscopic analyses of the cancer cells confirm the results of the cytotoxicity.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Cobre/química , DNA/química , Nanoestruturas/química , Neoplasias/patologia , Sonicação/métodos , Animais , Antineoplásicos/química , Bovinos , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Processamento de Imagem Assistida por Computador/métodos , Substâncias Intercalantes/química , Células MCF-7 , Microscopia Confocal/métodos , Neoplasias/tratamento farmacológico , Ligação Proteica , Soroalbumina Bovina/metabolismo , Células Tumorais Cultivadas
15.
J Fluoresc ; 26(3): 1007-20, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26987745

RESUMO

The focus of this article is preparation of a new kind of nanomaterial, the Zn(II) nanocomplex, to decrease growth of human carcinoma cell lines. The Zn(II) nanocomplex coordinated by phendione, [Zn(phendione)3](PF6)2 (where phendione is 1,10-phenanthroline-5,6-dione), has been synthesized by sonochemical method and characterized by FT-IR, dynamic light scattering (DLS), and scanning electron microscopy (SEM). The interaction of the complex and nanocomplex with fish sperm DNA (FS-DNA) has been investigated under physiological conditions by a series of experimental methods (fluorescence titration, viscosity, cyclic voltammetry (CV), competitive DNA-binding studies with ethidium bromide, and SEM). Results have indicated that the complex binds to FS-DNA by two biding modes, viz., electrostatic and partial insertion phendione between the base stacks of double-stranded DNA. The quenching constants (Ksv), binding constants (Kbin), and number of binding sites (n) at different temperatures, as well as thermodynamic parameters (ΔH(o), ΔS(o) and ΔG(o)) have been calculated for the BSA-complex system. Protein binding studies show that the complex and nanocomplex could bind with BSA. Results of synchronous fluorescence of BSA show that addition of the complex affect the microenvironment of both tyrosine and tryptophan residues during the binding process. The in vitro cytotoxicity of the complex and nanocomplex against the human carcinoma cell lines (MCF-7 and A-549) was evaluated by MTT assay. Results indicate that the complex and nanocomplex have greater cytotoxicity activity against MCF-7 with IC50 values of 0.2 and 0.9 mg/L, respectively. Results of the microscopic analyses of the cancer cells confirm results of cytotoxicity.


Assuntos
Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , DNA/metabolismo , Imagem Molecular/métodos , Nanoestruturas/química , Soroalbumina Bovina/metabolismo , Zinco/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Técnicas de Química Sintética , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Eletroquímica , Humanos , Modelos Moleculares , Conformação Molecular , Fenantrolinas/química , Termodinâmica , Ondas Ultrassônicas , Viscosidade
16.
Exp Appl Acarol ; 68(2): 251-65, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26597589

RESUMO

The tick Rhipicephalus (Boophilus) annulatus is one of the most important ectoparasites of bovines and is responsible for the transmission of different pathogens such as Babesia and Anaplasma. Cysteine proteases are involved in several host-tick interactions including invasion of host tissues, immune evasion, pathogen transmission, embryogenesis and blood digestion. In this study, the gene encoding R. annulatus cathepsin L-like enzyme (RaCL1) was cloned into pTZ57R/T vector, sequenced and analyzed using bioinformatics approaches. The nucleotide length of RaCL1 was 999 bp. Bioinformatics analysis showed 332 amino acids with an approximate molecular weight of 36.3 kDa which contained a signal peptide sequence (18 amino acids), pro-region (97 amino acids) and mature enzyme (217 amino acids). Multiple sequence alignment of the RaCL1 revealed high similarity to cathepsin L-like cysteine proteases from other tick species such as Rhipicephalus (Boophilus) microplus and Amblyomma variegatum. Based on bioinformatics analyses, results of this work suggest that RaCL1 can be a suitable candidate for the development of vaccine against R. annulatus.


Assuntos
Cisteína Proteases/isolamento & purificação , Rhipicephalus/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Catepsina L/química , Clonagem Molecular , Cisteína Proteases/metabolismo , Genes de Insetos , Irã (Geográfico) , Modelos Moleculares , Dados de Sequência Molecular , Rhipicephalus/genética , Alinhamento de Sequência
17.
Photochem Photobiol Sci ; 13(7): 1082-92, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24886806

RESUMO

The effects of mobile phone frequency electromagnetic field (RF-EMF, 940 MHz) on a stable cell line (HEK293T) harbouring the firefly luciferase gene were evaluated. A waveguide exposure system with 1 W input power provided the mean specific absorption rate of ≈0.09 W kg(-1) in 35 mm Petri dishes. The effects of exposure duration (15, 30, 45, 60 and 90 min) on luciferase activity and oxidative response elements were investigated. Endogenous luciferase activity was reduced after 30 and 45 min of continuous exposure, while after 60 min, the exposed cell lysate showed higher luciferase activity compared with the non-exposed control. Reactive oxygen species (ROS) generation was highest in the 30 min exposed cells as studied by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence. The observed boost in ROS was then followed by a sharp rise in catalase (CAT) and superoxide dismutase (SOD) activity and elevation of glutathione (GSH) during the 45 min exposure. Decrease in lipid peroxidation (malondialdehyde, MDA) was meaningful for the 45 and 60 min exposed cells. Therefore, it appears that an increase in the activity of luciferase after 60 min of continuous exposure could be associated with a decrease in ROS level caused by activation of the oxidative response. This ability in cells to overcome oxidative stress and compensate the luciferase activity could also be responsible for the adaptive response mechanism detected in ionizing radiation studies with RF-EMF pre-treatments.


Assuntos
Campos Eletromagnéticos , Luciferases de Vaga-Lume/metabolismo , Catalase/metabolismo , Fluoresceínas/química , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Glutationa/metabolismo , Células HEK293 , Humanos , Luciferases de Vaga-Lume/genética , Estresse Oxidativo/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo
18.
Appl Biochem Biotechnol ; 196(2): 971-991, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37285001

RESUMO

In this study, the third-generation polyamidoamine dendrimer was functionalized with a 5-amino-1H-tetrazole heterocycle to load the synthesis enzyme and its surface groups. Then, chitosan was attached to the dendrimer by a suitable linker, and finally, zinc oxide nanoparticles were inserted into dendrimer cavities to increase loading. FTIR, FESEM, TEM, and DLS analysis showed that this new dendrimer has specific branches, and ZnO nanoparticles were spread between the branches and connected with the branches and chitosan biopolymer. Also proved the presence of stabilized L-asparaginase enzyme and ZnO nanoparticles in the designed system. Furthermore, the extent of L-asparaginase enzyme loading and release was investigated in the laboratory with a dialysis bag. Examining the toxicity of the new third-generation polyamidoamine (PAMAM) dendrimeric nanocarrier based on chitosan-zinc oxide biopolymer (PAMAM-G3@ZnO-Cs nanocarrier) on the Jurkat cell line (human acute lymphoblastic leukemia) at pH 7.4 showed that this nanocarrier effectively encapsulates the drug L-asparaginase and slowly releases it and also preventing the growth of cancer cells. The activity of the loaded enzyme in the nanocarrier and the free enzyme was calculated. During the investigations, it was found that the enzyme attached to the nanocarrier is more stable than the free enzyme at optimal pH and temperature and at high temperatures, acidic and basic pHs. Vmax and Km values were lower for loaded enzymes. The synthesized PAMAM-G3@ZnO-Cs nanocarrier can be a promising candidate in the pharmaceutical industry and medical science for cancer treatment due to its biocompatibility, non-toxicity, stability, and slow release of L-asparaginase.


Assuntos
Quitosana , Dendrímeros , Nanopartículas , Poliaminas , Óxido de Zinco , Humanos , Asparaginase , Portadores de Fármacos , Diálise Renal
19.
J Biol Eng ; 18(1): 10, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38254151

RESUMO

This paper investigates the impact of taurine as an additive on the structural and functional stability of urate oxidase. First, the effect of the processing parameters for the stabilization of Urate Oxidase (UOX) using taurine was examined using the response surface methodology (RSM) and the central composite design (CCD) model. Also, the study examines thermodynamic and kinetic parameters as well as structural changes of urate oxidase with and without taurine. Fluorescence intensity changes indicated static quenching during taurine binding. The obtained result indicates that taurine has the ability to preserve the native structural conformation of UOX. Furthermore, molecular dynamics simulation is conducted in order to get insights into the alterations in the structure of urate oxidase in the absence and presence of taurine under optimal conditions. The molecular dynamics simulation section investigated the formation of hydrogen bonds (H-bonds) between different components as well as analysis of root mean square deviation (RMSD), root mean square fluctuations (RMSF) and secondary structure. Lower Cα-RMSD and RMSF values indicate greater stabilization of the taurine-treated UOX structure compared to the free enzyme. The results of molecular docking indicate that the binding of taurine to the UOX enzyme through hydrophobic interactions is associated with a negative value for the Gibbs free energy.

20.
Heliyon ; 10(7): e28676, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38617951

RESUMO

Non-viral gene delivery is a new therapeutic in the treating genetic disorders. The most important challenge in nonviral gene transformation is the immunogenicity of carriers. Nowadays, The immunogenicity of nanocarriers as a deliverer of nucleic acid molecules has received significant attention. In this research, hematite green nanocarriers were prepared in one step with rosemary extract. Synthetic nanocarriers were investigated by using XRD (X-ray diffraction analysis), FESEM-EDX (field emission scanning electron microscopy with energy dispersive X-Ray spectroscopy), HR-TEM (high-resolution transmission electron microscopy), VSM (value stream mapping), TGA- DTG (thermal gravimetric analysis-differential thermal analysis), FT-IR (fourier-transform infrared spectroscopy), BET (brunauer-emmett-teller) and BJH (barrett-joyner-halenda) analyses. The cytotoxicity of synthetic nanocarriers was evaluated on HEK-293Tcell lines at concentration of 1-500 µg/ml using MTT method. Finally, targeted transfection of GFP plasmid using green porous particles was performed using an external magnetic field. Biogenic hematite nanoparticles with hexagonal crystal structures have a 3D pile flower-like morphology. The existence of rosemary phytochemicals in the construction of nanoparticles has caused minimal toxicity and high biocompatibility of nanocarriers. Also, TGA studies confirmed the stability of bionic nanoparticles. Superparamagnetic green nanocarriers at concentrations above 500 µg/ml is not toxic to HEK293T cells. The delivery efficiency of the plasmid was optimal at an N/P ratio of 3. Therefore, the porous α-Fe2O3 green nanocarriers are non-viral and safe carriers with potential applications in gene therapy.

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