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1.
Yakugaku Zasshi ; 140(9): 1119-1128, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32879244

RESUMO

Humans are exposed to various xenobiotic electrophiles on a daily basis. Electrophiles form covalent adducts with nucleophilic residues of proteins. Redox signaling, which consists of effector molecules (e.g., kinases and transcription factors) and redox sensor proteins with low pKa cysteine residues, is involved in cell survival, cell proliferation, quality control of cellular proteins and oxidative stress response. Herein, we showed that at a low dose, xenobiotic electrophiles selectively modified redox sensor proteins through covalent modification of their reactive thiols, resulting in activation of a variety of redox signaling pathways. However, increasing the dose of xenobiotic electrophiles caused non-selective and extensive modification of cellular proteins involved in toxicity. Of interest, reactive sulfur species (RSS), such as hydrogen sulfide (H2S), cysteine persulfide (CysSSH), glutathione persulfide (GSSH) and even synthetic polysulfide (e.g., Na2S4), readily captured xenobiotic electrophiles, forming their sulfur adducts, which was associated with inactivation of the electrophiles. Our findings suggest that an adaptive response through redox signaling activation and RSS-mediated electrophile capturing is involved in the regulation of electrophilic stress.


Assuntos
Cisteína/análogos & derivados , Dissulfetos/metabolismo , Glutationa/análogos & derivados , Sulfeto de Hidrogênio/metabolismo , Oxirredução , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Animais , Cisteína/metabolismo , Glutationa/metabolismo , Humanos , Compostos de Sulfidrila/metabolismo , Xenobióticos/metabolismo
2.
Biotechniques ; 69(2): 108-112, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32459144

RESUMO

The outbreak of viral pneumonia caused by the novel coronavirus SARS-CoV-2 that began in December 2019 caused high mortality. It has been suggested that the main protease (Mpro) of SARS-CoV-2 may be an important target to discover pharmaceutical compounds for the therapy of this life-threatening disease. Remdesivir, ritonavir and chloroquine have all been reported to play a role in suppressing SARS-CoV-2. Here, we applied a molecular docking method to study the binding stability of these drugs with SARS-CoV-2 Mpro. It appeared that the ligand-protein binding stability of the alliin and SARS-CoV-2 Mpro complex was better than others. The results suggested that alliin may serve as a good candidate as an inhibitor of SARS-CoV-2 Mpro. Therefore, the present research may provide some meaningful guidance for the prevention and treatment of SARS-CoV-2.


Assuntos
Antivirais/farmacologia , Cisteína/análogos & derivados , Proteínas não Estruturais Virais/antagonistas & inibidores , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Alanina/análogos & derivados , Alanina/farmacologia , Antimaláricos/farmacologia , Betacoronavirus/enzimologia , Cloroquina/farmacologia , Cisteína/farmacologia , Cisteína Endopeptidases , Simulação de Acoplamento Molecular , Ritonavir/farmacologia
3.
J Mol Biol ; 432(7): 2141-2163, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32087196

RESUMO

Cells have evolved molecular chaperones that modulate phase separation and misfolding of amyloidogenic proteins to prevent neurodegenerative diseases. Protein disulfide isomerase (PDI), mainly located at the endoplasmic reticulum and also present in the cytosol, acts as both an enzyme and a molecular chaperone. PDI is observed to be S-nitrosylated in the brain of Alzheimer's disease patients, but the mechanism has remained elusive. We herein report that both wild-type PDI and its quadruple cysteine mutant only having chaperone activity, significantly inhibit pathological phosphorylation and abnormal aggregation of Tau in cells, and significantly decrease the mitochondrial damage and Tau cytotoxicity resulting from Tau aberrant aggregation, highlighting the chaperone property of PDI. More importantly, we show that wild-type PDI is selectively recruited by liquid droplets of Tau, which significantly inhibits phase separation and stress granule formation of Tau, whereas S-nitrosylation of PDI abrogates the recruitment and inhibition. These findings demonstrate how phase separation of Tau is physiologically regulated by PDI and how S-nitrosylation of PDI, a perturbation in this regulation, leads to disease.


Assuntos
Cisteína/análogos & derivados , Grânulos Citoplasmáticos/patologia , Transição de Fase , Isomerases de Dissulfetos de Proteínas/química , Isomerases de Dissulfetos de Proteínas/metabolismo , S-Nitrosotióis/metabolismo , Proteínas tau/química , Proteínas tau/metabolismo , Cisteína/metabolismo , Grânulos Citoplasmáticos/metabolismo , Células HEK293 , Humanos , Chaperonas Moleculares , Nitrosação , Dobramento de Proteína
4.
Inorg Chem ; 59(5): 3312-3320, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32049516

RESUMO

We carried out a detailed theoretical study on the mechanism of the carbene ligand substitution by cysteine and selenocysteine residues in an Au(I) bis-N-heterocyclic carbene complex in order to model the initial stages of the mechanism of action of this promising class of antitumor metallodrug. Both neutral and deprotonated capped Cys and Sec species were considered as possible nucleophiles in the ligand exchange reaction on the metal center to model the corresponding protein side chains. Energies and geometric structures of the possible transition states and reactant- and product-adducts involved in the substitution process have been calculated using density functional theory and local MP2. Reaction and activation enthalpies and free energies have been evaluated and indicate a slightly exothermic and exergonic process with reasonably low barriers, 21.3 and 19.6 kcal mol-1, respectively, for capped Cys and Sec, in good agreement with the experimental data available for the reaction with free amino acids. The results suggest a mechanism for the ligand exchange reaction involving an anionic thiolate or selenothiolate species coupled to an explicit proton transfer to the leaving carbene from the acidic component of the buffer. The presence of a buffer is necessary both in in vitro experiments and under physiological conditions, and its proton reservoir behavior reveals the importance of the environmental effects in carbene substitution by biological nucleophiles.


Assuntos
Antineoplásicos/química , Cisteína/química , Ouro/química , Compostos Heterocíclicos/química , Metano/análogos & derivados , Antineoplásicos/síntese química , Cisteína/análogos & derivados , Teoria da Densidade Funcional , Metano/química , Estrutura Molecular
5.
Life Sci ; 245: 117367, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32001265

RESUMO

AIMS: The present study determines the effect of administration of novel antioxidant astaxanthin-s-allyl cysteine biconjugate (AST-SAC) against streptozotocin-induced diabetes mellitus (DM) in rats. MAIN METHODS: AST-SAC (1 mg/kg/day) was treated against DM in rats for 45 days. The oxidative stress, antioxidants level, insulin secretion, activities of various carbohydrate metabolizing enzymes were studied. The glucose uptake in L6 myotubes was studied. In addition, in silico analysis of interaction of AST-SAC with proteins such as insulin receptor (IR) and 5'-adenosine monophosphate-activated protein kinase (AMPK) were carried out. KEY FINDINGS: Administration of AST-SAC in DM rats has protected the mitochondrial function (decreased oxidative stress and normalized oxidative phosphorylation activities) and antioxidant capacity of the pancreas which has resulted in beta cells rejuvenation and insulin secretion restoration. AST-SAC decreased the alpha-glucosidases activities to bring glycemic control in DM rats. Due to these effects the glycoprotein components and lipids were restored to near normalcy in DM rats. AST-SAC protected the antioxidant status of liver, kidney and plasma; and curbed the progression of secondary complications of DM. AST-SAC treatment stimulated glucose uptake in L6 myotubes in in vitro. To support this observation, AST-SAC interacted with proteins such as IR and AMPK in silico. SIGNIFICANCE: AST-SAC can be considered as "multi-target-directed ligand", that is, through these manifold effects, AST-SAC has been able to prevail over DM in rats.


Assuntos
Antioxidantes/uso terapêutico , Cisteína/análogos & derivados , Cisteína/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Xantofilas/uso terapêutico , Animais , Antioxidantes/farmacologia , Colesterol/metabolismo , Cisteína/farmacologia , Diabetes Mellitus Experimental/metabolismo , Glucose/metabolismo , Masculino , Mitocôndrias/metabolismo , Simulação de Acoplamento Molecular , Ratos , Ratos Sprague-Dawley , Triglicerídeos/metabolismo , Xantofilas/farmacologia
6.
Toxicol Lett ; 324: 65-74, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32035980

RESUMO

Paracetamol (acetaminophen, APAP) is the most frequently used analgesic drug worldwide. However, patients in several specific populations can have an increased exposure to toxic APAP metabolites. Therefore, APAP-protein adducts have been proposed as an alternative marker for the assessment of APAP intoxications and as an effective tool to study and steer APAP treatment in patients with an increased risk of APAP-induced liver damage. These adducts have been determined in plasma or serum as a matrix. Blood microsampling allows the determination of a variety of analytes, including protein adducts, in a drop of blood, facilitating convenient follow-up of patients in a home-sampling context, as well as repeated sampling of pediatric patients. We therefore evaluated the use of blood-based volumetric microsamples for the quantification of APAP-protein adducts. Quantitative methods for the determination of APAP-protein adducts in dried blood and dried plasma volumetric absorptive microsamples were developed and validated. Also a preliminary evaluation of pediatric patient dried blood microsamples was conducted. Method validation encompassed the evaluation of selectivity, carry over, calibration model, accuracy and precision, matrix effect, recovery and the effect of the hematocrit on the recovery, dilution integrity, and stability. All pre-set acceptance criteria were met, except for stability. Spiking of blank blood with APAP revealed a concentration-dependent ex vivo formation of APAP-protein adducts, resulting in a response for the measurand APAP-Cys, with an apparent role for the red blood cell fraction. Analysis of authentic samples, following intake of APAP at therapeutic dosing, revealed much higher APAP-Cys concentrations in dried blood vs. dried plasma samples, making interpretation of the results in the context of published intervals difficult. In addition, in contrast to what was observed during method validation, the data obtained for the patient samples showed a high and unacceptable variation. We conclude that, for a combination of reasons, dried blood is not a suitable matrix for the quantification of APAP-protein adducts via the measurement of the APAP-Cys digestion product. The collection of plasma or serum, either in the form of a liquid sample or a dried microsample for this purpose is advised.


Assuntos
Acetaminofen/análogos & derivados , Acetaminofen/sangue , Analgésicos não Entorpecentes/sangue , Teste em Amostras de Sangue Seco/métodos , Coleta de Amostras Sanguíneas , Cisteína/análogos & derivados , Cisteína/sangue , Hematócrito , Humanos , Ligação Proteica , Controle de Qualidade
7.
Mater Sci Eng C Mater Biol Appl ; 108: 110369, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923961

RESUMO

Bionanocomposite materials were developed from the assembly of polymer-coated copper-cystine high-aspect ratio structures (CuHARS) and cellulose fibers. The coating of the metal-organic materials with polyallylamine hydrochloride (PAH) allows their covalent linkage to TEMPO-oxidized cellulose by means of EDC/NHS. The resulting materials can be processed as films or macroporous foams by solvent casting and lyophilization, respectively. The films show good mechanical behavior with Young's moduli around 1.5 GPa as well as resistance in water, while the obtained foams show an open network of interconnected macropores with average diameters around 130 µm, depending on the concentration of the initial suspension, and compression modulus values around 450 kPa, similar to other reported freeze-dried nanocellulose-based aerogels. Based on these characteristics, the cellulose/PAH-CuHARS composites are promising for potential biomedical applications as implants or wound dressing materials. They have proved to be effective in the decomposition of low molecular weight S-nitrosothiols (RSNOs), similar to those existing in blood, releasing nitric oxide (NO). This effect is attributed to the presence of copper in the crystalline structure of the CuHARS building unit, which can be gradually released in the presence of redox species like ascorbic acid, typically found in blood. The resulting biomaterials can offer the interesting properties associated with NO, like antimicrobial activity as preliminary tests showed here with Escherichia coli and Staphylococcus epidermidis. In the presence of physiological concentration of RSNOs the amount of generated NO (around 360 nM) is not enough to show bactericidal effect on the studied bacteria, but it could provide other properties inherent to NO even at low concentration in the nM range like anti-inflammatory and anti-thrombotic effects. The cytotoxic effect recorded of the films on rat brain endothelial cells (BMVECs) is least significant and proves them to be friendly enough for further biological studies.


Assuntos
Materiais Biocompatíveis/química , Celulose/química , Cobre/química , Cistina/química , Óxido Nítrico/análise , Animais , Encéfalo/irrigação sanguínea , Catálise , Sobrevivência Celular/efeitos dos fármacos , Celulose/ultraestrutura , Contagem de Colônia Microbiana , Cisteína/análogos & derivados , Cisteína/análise , Módulo de Elasticidade , Células Endoteliais/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Cinética , Microvasos/citologia , Poliaminas/química , Porosidade , Ratos , S-Nitrosotióis/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/crescimento & desenvolvimento
8.
Eur J Pharmacol ; 869: 172893, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31883915

RESUMO

Organosulfur compounds, such as L-cysteine, allicin and other sulfur-containing organic compounds in Allium species, have been proposed to possess many important physiological and pharmacological functions. A novel L-cysteine derivative, t-Butyl S-allylthio-L-cysteinate (5P39), was designed and synthesized by combining L-cysteine derivative and allicin pharmacophore through a disulfide bond. This study aimed to explore the effects and mechanisms of 5P39 on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. At the experimental concentration (5, 10 and 20 µM), 5P39 suppressed the excessive secretion of nitric oxide (NO) and interleukin-6 (IL-6) in mice peritoneal macrophages stimulated by LPS. A mouse model of ALI was established by tracheal instillation of LPS for 2 h before 5P39 (30 and 60 mg/kg) administration. The results showed that 5P39 treatment down-regulated the wet/dry weight ratio (W/D ratio) of lungs and reduced the protein concentration, the number of total cells as well as the myeloperoxidase (MPO) activity in bronchoalveolar lavage fluid (BALF). 5P39 administration improved the histopathological changes of lungs in ALI mice with the decreased levels of pro-inflammatory cytokines in BALF. The inhibitory effects of 5P39 on the toll-like receptor 4 (TLR4) expression and macrophages accumulation in lung tissues were observed by immunohistochemistry. Additionally, 5P39 significantly attenuated the LPS-activated high expression of key proteins in TLR4/MyD88 signaling pathway. Taken together, the present study showed that 5P39 effectively alleviate the severity of ALI, and its mechanism might relate to the inhibition of LPS-activated TLR4/MyD88 signaling pathway, demonstrating a promising potential for further development into an anti-inflammatory drug candidate.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Cisteína/farmacologia , Cisteína/uso terapêutico , Fator 88 de Diferenciação Mieloide/metabolismo , Receptor 4 Toll-Like/metabolismo , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Animais , Líquido da Lavagem Broncoalveolar/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cisteína/análogos & derivados , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Lipopolissacarídeos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
9.
Chem Commun (Camb) ; 56(6): 956-959, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31858094

RESUMO

On-resin intramolecular native chemical ligation (NCL) assisted by N-ethylcysteine using Fmoc/SPPS to obtain cyclic peptides is described. N-terminal cysteine-containing peptides were subjected to NCL conditions leading to cyclization-cleavage reactions and consecutive S → N shift, rendering cyclic peptides in good yields and purities. The compounds were evaluated against P. falciparum 3D7.


Assuntos
Peptídeos Cíclicos/síntese química , Compostos de Sulfidrila/química , Cisteína/análogos & derivados , Cisteína/química , Estrutura Molecular , Peptídeos Cíclicos/química , Resinas Sintéticas/química
10.
Proc Natl Acad Sci U S A ; 116(51): 25634-25640, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31801874

RESUMO

How changes in enzyme structure and dynamics facilitate passage along the reaction coordinate is a fundamental unanswered question. Here, we use time-resolved mix-and-inject serial crystallography (MISC) at an X-ray free electron laser (XFEL), ambient-temperature X-ray crystallography, computer simulations, and enzyme kinetics to characterize how covalent catalysis modulates isocyanide hydratase (ICH) conformational dynamics throughout its catalytic cycle. We visualize this previously hypothetical reaction mechanism, directly observing formation of a thioimidate covalent intermediate in ICH microcrystals during catalysis. ICH exhibits a concerted helical displacement upon active-site cysteine modification that is gated by changes in hydrogen bond strength between the cysteine thiolate and the backbone amide of the highly strained Ile152 residue. These catalysis-activated motions permit water entry into the ICH active site for intermediate hydrolysis. Mutations at a Gly residue (Gly150) that modulate helical mobility reduce ICH catalytic turnover and alter its pre-steady-state kinetic behavior, establishing that helical mobility is important for ICH catalytic efficiency. These results demonstrate that MISC can capture otherwise elusive aspects of enzyme mechanism and dynamics in microcrystalline samples, resolving long-standing questions about the connection between nonequilibrium protein motions and enzyme catalysis.


Assuntos
Cristalografia por Raios X/métodos , Enzimas , Catálise , Cisteína/análogos & derivados , Cisteína/química , Cisteína/metabolismo , Enzimas/química , Enzimas/metabolismo , Enzimas/ultraestrutura , Hidroliases/química , Hidroliases/metabolismo , Hidroliases/ultraestrutura , Modelos Moleculares , Conformação Proteica
11.
Adv Clin Exp Med ; 28(12): 1609-1614, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31851788

RESUMO

BACKGROUND: During cerebral ischemia, energy restoration through the regulation of glucose transporters and antioxidant defense mechanisms is essential to maintain cell viability. Antioxidant therapy has been considered effective to attenuate brain damage; moreover, the regulation of transcription factors that positively regulate the expression of glucose transporters is associated with this therapy. Recently, it has been reported that the use of antioxidants such as S-allylcysteine (SAC), a component of aged garlic extract (AGE), improves survival in experimental models of cerebral ischemia. OBJECTIVES: The aim of this study was to determine the effect of AGE and SAC on the level of mRNA expression of the main neuronal glucose transporter (GLUT3) and the glutamate cysteine ligase catalytic subunit (GCLC) in rats with transient focal cerebral ischemia. MATERIAL AND METHODS: Cerebral ischemia was induced in male Wistar rats by middle cerebral artery occlusion (MCAO) for 2 h. The animals were sacrificed after different reperfusion times (0-48 h). Animals injected with AGE (360 mg/kg, intraperitoneally (i.p.)) and SAC (300 mg/kg, i.p.) at the beginning of reperfusion were sacrificed after 2 h. The mRNA expression level was analyzed in the fronto-parietal cortex using quantitative polymerase chain reaction (qPCR). RESULTS: Two major increases in GLUT3 expression at 1 h and 24 h of reperfusion were found. Both treatments increased GLUT3 and GCLC mRNA levels in control and under ischemic/reperfusion injury animals. CONCLUSIONS: This data suggests that SAC and AGE might induce neuroprotection, while controlling reactive oxygen species (ROS) levels, as indicated by the increase in GCLC expression, and regulating the energy content of the cell by increasing glucose transport mediated by GLUT3.


Assuntos
Isquemia Encefálica , Alho , Proteínas Facilitadoras de Transporte de Glucose/metabolismo , Glutamato-Cisteína Ligase/metabolismo , Fármacos Neuroprotetores , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Isquemia Encefálica/metabolismo , Cisteína/análogos & derivados , Cisteína/farmacologia , Alho/química , Proteínas Facilitadoras de Transporte de Glucose/efeitos dos fármacos , Glutamato-Cisteína Ligase/efeitos dos fármacos , Masculino , Fármacos Neuroprotetores/uso terapêutico , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo
12.
Acta Biochim Pol ; 66(4): 533-544, 2019 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-31883321

RESUMO

Sulfane sulfur is a divalent sulfur atom bonded to another sulfur which is very reactive and labile. Compounds containing this reactive sulfur include persulfides, polysulfides, thiosulfate, thiosulfinates, polythionates, and elemental sulfur. Sulfane sulfur appears in a number of biologically important compounds, including thiocysteine, thiocystine and thiotaurine, products of the cysteine metabolism, as well as glutathione persulfide. Sulfane sulfur compounds can modify cysteine residues in proteins via an S-sulfhydration reaction to produce protein persulfides. It has been also postulated that cysteine persulfides can be incorporated into proteins during translation. Recently, the sulfane sulfur compounds, especially the persulfides and polysulfides, have attracted increasing interest due to their regulatory and antioxidant properties. Compounds containing sulfane sulfur are also regarded as a form of H2S storage, which can easily release this gasotransmitter in response to biological signals. Both reactive sulfur species (H2S and sulfane sulfur) always coexist in biological systems. This review is focused on new findings in the field of sulfane sulfur's biological role, and disruption of its level in some patho/physiological conditions. A few sulfane sulfur donors with potential applications are presented. In recent years, in parallel to increasing interest in biological importance of sulfane sulfur, new analytical methods have been developed for sensitive and reliable determination of its level in the cells and tissues.


Assuntos
Antioxidantes/metabolismo , Gasotransmissores/metabolismo , Sulfetos/metabolismo , Enxofre/metabolismo , Antioxidantes/química , Cisteína/análogos & derivados , Cisteína/química , Dissulfetos/química , Gasotransmissores/química , Glutationa/análogos & derivados , Glutationa/química , Humanos , Proteínas/química , Sulfetos/química , Enxofre/química , Tiossulfatos/química
13.
Mikrochim Acta ; 186(12): 847, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31776791

RESUMO

A new colorimetric method that can be used to rapidly detect toxic ricin is demonstrated. Lactosylated cysteine-functionalized gold nanoparticles (Au@LACY NPs) were prepared by a one-pot reaction and employed as optical probes for determination of ricin B chain. It is found that the Au@LACY NPs undergo aggregation in the presence of ricin B chain. This leads to surface plasmon coupling effects of the particles and a color change from red to blue, with absorption maxima at 519 and 670 nm, respectively. The feasibility of using the current approach for quantitative analysis of ricin B chain is also demonstrated. The calibration plot is generated by plotting the ratio of the absorbance at the wavelength of 634 to 518 nm versus the concentration of the ricin B chain. The spectrophotometric method has a ~29 pM (~ 0.91 ng·mL-1) detection limit, and the sample with the concentration of ~ 400 pM (~ 13 ng·mL-1) can be detected visually. Graphical abstractSchematic representation of using lactosylated cysteine capped gold nanoparticles (Au@LACY NPs) as colorimetric probes for the ricin B chain through surface plasmon coupling effects. Sample solution turns from red to blue in the presence of ricin B chain.


Assuntos
Colorimetria/métodos , Corantes/química , Cisteína/análogos & derivados , Lactose/análogos & derivados , Nanopartículas Metálicas/química , Ricina/análise , Contaminação de Alimentos/análise , Ouro/química , Limite de Detecção , Espectrofotometria Ultravioleta/métodos , Amido/química
14.
Medicine (Baltimore) ; 98(46): e16525, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31725599

RESUMO

To evaluate the clinical value of NeuroGam software in assessing the brain foci perfusion changes by TC-ECD single photon emission computed tomography/computed tomography (SPECT/CT) brain imaging in patients with Moyamoya Disease (MMD).Seventy-two patients with MMD who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass combined with encephalo-duro-myo-synangiosis (EDMS) surgical revascularization were included. Baseline and follow-up TC-ECD SPECT/CT brain scans were performed on all patients at least twice before and after operation. Pre- and post-SPECT dicom images were reoriented into Talairach space using NeuroGam Software package. Additional visual analysis was performed. Differences mean pixel value between pre- and post- operation brain perfusion were assessed with paired t test and McNemar test.Significant differences in the number of hypoperfusion foci were found between visual assessment and NeuroGam aided assessment. More hypoperfusion foci were found by NeuroGam software aided assessment in the frontal, parietal, temporal, occipital lobe, thalamus, basal ganglia and cerebellum before and after surgery (P < .0001). According to NeuroGam software assessment, the perfusion of frontal, parietal, temporal lobe, anterior and middle cerebral regions on the operative side significantly improved before and after surgery (t = -3.734, t = -3.935, t = -5.099, t = -4.006, t = -5.170, all P < .001). However, no significant differences were found in the occipital lobe (t = -1.962, P = .054), thalamus (t = 1.362, P = .177), basal ganglia (t = -2.394, P = .019), and cerebellum (t = 1.383, P = .171) before and after surgery.The NeuroGam software provides a quantitative approach for monitoring surgical effect of MMD in a variable time (3-12 months after surgery). It could discover the perfusion changes that are neglected in conventional visual assessment.


Assuntos
Cisteína/análogos & derivados , Interpretação de Imagem Assistida por Computador/métodos , Doença de Moyamoya/diagnóstico por imagem , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/estatística & dados numéricos , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Revascularização Cerebral/métodos , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/cirurgia , Doença de Moyamoya/cirurgia , Período Pós-Operatório , Período Pré-Operatório , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/métodos , Software , Artérias Temporais/cirurgia , Resultado do Tratamento , Adulto Jovem
15.
Colloids Surf B Biointerfaces ; 184: 110548, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31614252

RESUMO

Molecular interactions between l-cysteine (Cys) and its ester derivatives (Cysx); l-cysteine ethyl ester (CE), l-cysteine methyl ester (CM) and N-acetyl l-cysteine (NAC) with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayers were investigated using Langmuir film balance technique. The effect of charge on monolayers made of cysteine and three ester derivatives with DPPC was investigated by working with un-buffered and buffered subphases. Also, the effects of cysteine derivatives interaction with DPPC monolayers were studied measuring the change in the surface tension upon aminoacid injection in the subphase whilst keeping lipid molecular density and lateral packing controlled. Cysteine and its ester derivatives showed interfacial activity reducing the air/water surface tension (πi) by 4 mN m-1. However, ester derivatives were able to insert into preformed DPPC monolayers at much higher surface pressures (Δπ), indicating a preferential interaction of Cysx with DPPC. The results indicate that, although the different derivatives of cysteine presented low surface activity, they were able to favourably interact with DPPC monolayers. Also, compression isotherms experiments in binary mixtures indicate that the more surface active compounds stabilized the gel phase of DPPC. The charge on cysteine and its derivatives did not increase the observed effects.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Cisteína/química , Adsorção , Cisteína/análogos & derivados , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
16.
Int J Med Sci ; 16(8): 1180-1187, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31523181

RESUMO

Objective: The effects of pre-treatments from s-methyl cysteine (SMC) alone, syringic acid (SA) alone and SMC plus SA against kainic acid (KA) induced injury in nerve growth factor (NGF) differentiated PC12 cells were investigated. Methods: NGF-differentiated PC12 cells were treated with 1 µM SMC, 1 µM SA or 0.5 µM SMC plus 0.5 µM SA for 2 days. Subsequently, cells were further treated by 150 µM KA. Results: KA suppressed Bcl-2 mRNA expression, enhanced Bax mRNA expression and casued cell death. SMC was greater than SA, and similar as SMC+SA in increasing Bcl-2 mRNA expression. SMC+SA led to greater increase in mitochondrial membrane potential and cell survival than SMC or SA alone. SMC+SA resulted in more reduction in reactive oxygen species and tumor necrosis factor-alpha generation, more increase in glutathione content and glutathione reductase activity than SMC or SA alone. KA up-regulated protein expression of nuclear factor kappa B (NF-κB) p65 and phosphorylated p38 (p-p38). SMC or SA pre-treatments alone limited protein expression of both factors. SMC+SA resulted in more suppression in NF-κB p65 and p-p38 expression. KA decreased glutamine level, increased glutamate level and stimulated calcium release. SMC pre-treatments alone reversed these alterations. SMC alone elevated glutamine synthetase (GS) activity and mRNA expression. SMC+SA led to greater GS activity and mRNA expression than SMC pre-treatments alone. Conclusion: These findings suggested that this combination, SMC+SA, might provide greater protective potent for neuronal cells.


Assuntos
Cisteína/análogos & derivados , Ácido Gálico/análogos & derivados , Fator de Crescimento Neural/farmacologia , Fármacos Neuroprotetores/farmacologia , Animais , Cálcio/metabolismo , Diferenciação Celular/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/patologia , Sobrevivência Celular , Cisteína/farmacologia , Sinergismo Farmacológico , Ácido Gálico/farmacologia , Ácido Caínico/toxicidade , Potencial da Membrana Mitocondrial/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Células PC12 , Ratos , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
17.
Chin J Nat Med ; 17(7): 517-524, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31514983

RESUMO

We investigated the potential hepatoprotective effect of Radix Bupleuri (RB) by inducing acute liver injury (ALI) in an animal model using acetaminophen (APAP) after pretreatment with RB aqueous extract for three consecutive days. Compared to those of the APAP group, the biochemical and histological results of the RB pretreatment group showed lower serumaspartate transaminase (AST) and alanine transaminase (ALT) levels as well as less liver damage. Pharmacokinetic study of the toxicity related marker acetaminophen-cysteine (APC) revealed a lower exposure level in rats, suggesting that RB alleviated APAP-induced liver damage by preventing glutathione (GSH) depletion. The results of cocktail approach showed significant inhibition of CYP2E1 and CYP3A activity. Further investigation revealed the increasing of CYP2E1 and CYP3A protein was significantly inhibited in pretreatment group, while no obvious effect on gene expression was found. Therefore, this study clearly demonstrates that RB exhibited significant protective action against APAP-induced acute live injury via pretreatment, and which is partly through inhibiting the increase of activity and translation of cytochrome P450 enzymes, rather than gene transcription.


Assuntos
Acetaminofen/análogos & derivados , Bupleurum/química , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Cisteína/análogos & derivados , Inibidores das Enzimas do Citocromo P-450/uso terapêutico , Extratos Vegetais/uso terapêutico , Acetaminofen/farmacocinética , Animais , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Cisteína/farmacocinética , Inibidores das Enzimas do Citocromo P-450/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Modelos Animais de Doenças , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Endogâmicos ICR , Fitoterapia , Extratos Vegetais/farmacologia , Ratos Wistar
18.
Nucl Med Biol ; 74-75: 19-24, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31450071

RESUMO

Glucagon-like peptide-1 receptor (GLP-1R) is a kind of G protein coupled receptor which regulates the insulin secretion and serves as potential target in the diagnosis of functional pancreas neuroendocrine tumor. The aim of this study was to evaluate the feasibility of GLP-1R targeted tracer [68Ga]Ga-NOTA-MAL-Cys39-exendin-4 in the detection of insulinoma. METHODS: NOTA-MAL-Cys39-exendin-4 was synthesized and then radiolabeled with gallium-68 in iQS® Ga-68 Fluidic Labeling Module. The in vitro binding affinity and cell uptake studies were evaluated in INS-1 cells. The in vivo micro-PET/CT imaging and biodistribution studies were performed on INS-1 xenograft tumor models. RESULTS: [68Ga]Ga-NOTA-MAL-Cys39-exendin-4 can be efficiently radiolabelled with a yield of about 85% (non-decay corrected) and radiochemical purity of >95% with a favorable stability. The molar activity was at least 145.5 GBq/µmol. The affinity (IC50) for [68Ga]Ga-NOTA-MAL-Cys39-exendin-4 was 12.99 ±â€¯0.81 nM. Micro-PET/CT images showed intense tumor uptake with good contrast to background. Biodistribution study showed the predominant uptake was in the kidney, followed by pancreas, and the liver and spleen just showed mild uptake in the blood-pool phase with rapid clearance. At 1 h post- injection, the tumor to blood, muscle and pancreas ratios were 30.64, 40.21 and 6.46, respectively. Blocking studies showed significantly decreased tumor uptake, which further confirmed binding affinity of [68Ga]Ga-NOTA-MAL-Cys39-exendin-4 to GLP-1R. CONCLUSION: [68Ga]Ga-NOTA-MAL-Cys39-exendin-4 was easily synthesized with high yield, favorable biodistribution and high affinity to islet tumor cell, making the tracer may have great potential in the detection of GLP-1R positive tumor such as an insulinoma.


Assuntos
Exenatida/química , Radioisótopos de Gálio/farmacocinética , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Insulinoma/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/farmacocinética , Animais , Cisteína/análogos & derivados , Cisteína/química , Feminino , Radioisótopos de Gálio/química , Insulinoma/diagnóstico por imagem , Insulinoma/metabolismo , Maleimidas/química , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/metabolismo , Fragmentos de Peptídeos/química , Compostos Radiofarmacêuticos/química , Ratos , Distribuição Tecidual , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Int J Biol Macromol ; 140: 1147-1157, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31442505

RESUMO

In Alzheimer's disease (AD) and diabetes-associated cognitive decline, the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity is increased. AChE exists as different globular molecular forms: tetramer (G4), dimer (G2) and monomer (G1). In adult brain, G4 form is abundant however in AD, the ratio of lower molecular forms (G1) to G4 form increased. Hence, the present study delineated the inhibition of novel astaxanthin-s-allyl cysteine (AST-SAC) against BChE and various molecular forms of AChE. Cobra venom, human erythrocyte and Electrophorus electricus was used as source of G1, G2 and G4 form of AChE. AST-SAC showed inhibition against G1 (IC50 = 0.72 µM, competitive, Ki = 0.66 µM), G2 (IC50 = 0.65 µM, mixed, Ki = 0.50 µM) and G4 (IC50 = 0.67 µM, competitive, Ki = 0.67 µM) form of AChE. AST-SAC inhibited human brain AChE (IC50 = 0.84 µM, competitive, Ki = 0.53 µM) and human serum BChE (IC50 = 0.80 µM, competitive, Ki = 0.58 µM). In silico analysis revealed the interaction of AST-SAC with the amino acids present in peripheral anionic and catalytic site of human AChE and BChE. Molecular dynamics simulation confirmed the stable interaction of AST-SAC in the active site gorge of AChE and BChE.


Assuntos
Acetilcolinesterase/metabolismo , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/farmacologia , Cisteína/análogos & derivados , Acetilcolinesterase/química , Animais , Encéfalo/enzimologia , Butirilcolinesterase/sangue , Butirilcolinesterase/química , Inibidores da Colinesterase/química , Simulação por Computador , Cisteína/química , Cisteína/farmacologia , Humanos , Simulação de Dinâmica Molecular , Xantofilas/química , Xantofilas/farmacologia
20.
Biomol NMR Assign ; 13(2): 371-376, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31377986

RESUMO

DJ-1 is a highly conserved soluble protein that is associated to several cellular pathways. In humans, DJ-1 has been implicated in several pathologies such as cancer, Parkinson's disease and amyotrophic lateral sclerosis. Several roles have been attributed to DJ-1, including defense against oxidative stress, chaperone activity and proteasome regulation. The recent finding that DJ-1 acts as a protein and DNA deglycase further confirms the protective function of DJ-1 and suggests a common mechanism of action in the various pathways in which DJ-1 is involved. Cysteine 106, located in the putative active site of DJ-1, is critical for the biological activity of DJ-1 and is easily oxidized to cysteine-sulfinate. While such oxidation modulates DJ-1 activity, the underlying molecular mechanism has not yet been elucidated. Cysteine oxidation does not perturb the protein structure, therefore changes in protein dynamics in solution could modulate its function. Here, we report a revised and completed (98%) backbone assignment of reduced DJ-1, together with the backbone assignment of oxidized DJ-1. Chemical shift perturbation is observed in several regions across the sequence, while no changes in secondary structure are observed. These data will provide the starting point for further characterization of the changes in the backbone dynamics of DJ-1 upon oxidation in solution at physiological temperature.


Assuntos
Cisteína/análogos & derivados , Ressonância Magnética Nuclear Biomolecular , Proteína Desglicase DJ-1/química , Proteína Desglicase DJ-1/metabolismo , Cisteína/metabolismo , Humanos , Oxirredução
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