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1.
J Med Chem ; 64(5): 2501-2520, 2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33631934

RESUMO

SUMOylation is a reversible post-translational modification that regulates protein function through covalent attachment of small ubiquitin-like modifier (SUMO) proteins. The process of SUMOylating proteins involves an enzymatic cascade, the first step of which entails the activation of a SUMO protein through an ATP-dependent process catalyzed by SUMO-activating enzyme (SAE). Here, we describe the identification of TAK-981, a mechanism-based inhibitor of SAE which forms a SUMO-TAK-981 adduct as the inhibitory species within the enzyme catalytic site. Optimization of selectivity against related enzymes as well as enhancement of mean residence time of the adduct were critical to the identification of compounds with potent cellular pathway inhibition and ultimately a prolonged pharmacodynamic effect and efficacy in preclinical tumor models, culminating in the identification of the clinical molecule TAK-981.


Assuntos
Antineoplásicos/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Neoplasias/tratamento farmacológico , Ácidos Sulfônicos/uso terapêutico , Sumoilação/efeitos dos fármacos , Enzimas Ativadoras de Ubiquitina/antagonistas & inibidores , Adenosina/análogos & derivados , Adenosina/metabolismo , Adenosina/uso terapêutico , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Linhagem Celular Tumoral , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Humanos , Camundongos , Estrutura Molecular , Ligação Proteica , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Relação Estrutura-Atividade , Ácidos Sulfônicos/síntese química , Ácidos Sulfônicos/metabolismo , Enzimas Ativadoras de Ubiquitina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Ecotoxicol Environ Saf ; 208: 111742, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396068

RESUMO

The indiscriminate disposal of olsalazine in the environment poses a threat to human health and natural ecosystems because of its cytotoxic and genotoxic nature. In the present study, degradation efficiency of olsalazine by the marine-derived fungus, Aspergillus aculeatus (MT492456) was investigated. Optimization of physicochemical parameters (pH. Temperature, Dry weight) and redox mediators {(2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), p-Coumaric acid and 1-hydroxybenzotriazole (HOBT)} was achieved with Response Surface Methodology (RSM)-Box-Behnken Design (BBD) resulting in 89.43% removal of olsalazine on 7th day. The second-order polynomial regression model was found to be statistically significant, adequate and fit with p < 0.0001, F value=41.87 and correlation coefficient (R2=0.9826). Biotransformation was enhanced in the redox mediator-laccase systems resulting in 99.5% degradation of olsalazine. The efficiency of ABTS in the removal of olsalazine was more pronounced than HOBT and p-Coumaric acid in the laccase-mediator system. This is attributed to the potent nature of the electron transfer mechanism deployed during oxidation of olsalazine. The pseudo-second-order kinetics revealed that the average half-life (t1/2) and removal rates (k1) increases with increasing concentrations of olsalazine. Michaelis-Menten kinetics affirmed the interaction between laccase and olsalazine under optimized conditions with maximum removal rate, Vmax=111.11 hr-1 and half-saturation constant, Km=1537 mg L-1. At the highest drug concentration (2 mM); 98%, 95% and 93% laccase was remarkably stabilized in the enzyme-drug degradation system by HOBT, ABTS and p-Coumaric acid respectively. This study further revealed that the deactivation of laccase by the redox mediators is adequately compensated with enhanced removal of olsalazine.


Assuntos
Ácidos Aminossalicílicos/metabolismo , Anti-Inflamatórios não Esteroides/metabolismo , Aspergillus/fisiologia , Biodegradação Ambiental , Ecossistema , Fungos/metabolismo , Humanos , Cinética , Lacase/metabolismo , Oxirredução , Ácidos Sulfônicos/metabolismo , Triazóis
3.
Toxicol Lett ; 339: 78-87, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33387635

RESUMO

Obesity is a complex disease with many causes, including a possible role for environmental chemicals. Perfluorohexane sulfonate (PFHxS) is one of many per- and polyfluoroalkyl substances (PFASs) frequently detected in humans and it is suspected to be an obesogenic compound. We examined the potential long-term effects of PFHxS on metabolic parameters in rats after developmental exposure to 0.05, 5 or 25 mg/kg bw/day, with or without co-exposure to a background mixture of twelve endocrine disrupting chemicals (EDmix). Both male and female offspring showed signs of lower birth weight following intrauterine exposure. Female offspring exposed to both PFHxS and EDmix had increased body weight in adulthood. The retroperitoneal fat pad was larger in the PFHxS-exposed female offspring when compared to those exposed to EDmix alone. An attempt to detect putative molecular markers in the fat tissue by performing whole transcriptome profiling revealed no significant changes between groups and there were no significant effects on plasma leptin levels in exposed females. Our results show that early life exposure to endocrine disrupting chemicals can influence body weight later in life, but the effect is not necessarily reflected in changed gene expression in the fat tissue.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Disruptores Endócrinos/metabolismo , Disruptores Endócrinos/toxicidade , Obesidade/induzido quimicamente , Ácidos Sulfônicos/metabolismo , Ácidos Sulfônicos/toxicidade , Ganho de Peso/efeitos dos fármacos , Adipócitos/metabolismo , Adulto , Animais , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos
4.
Dalton Trans ; 49(16): 5029-5033, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32236202

RESUMO

Inspired by the structural features of native peroxidases, an artificial peroxidase was rationally designed using F43Y myoglobin with a Tyr-heme cross-link by further introduction of key residues, including both a distal Arg and a Trp close to the heme group, which exhibits an enhanced peroxidase activity similar to the most efficient native horseradish peroxidase. This study provides a simple approach for design of artificial heme enzymes by the combination of catalytic elements of native enzymes with the post-translational modifications of heme proteins.


Assuntos
Reagentes para Ligações Cruzadas/química , Mioglobina/química , Peroxidases/química , Tirosina/química , Benzotiazóis/química , Benzotiazóis/metabolismo , Biocatálise , Reagentes para Ligações Cruzadas/metabolismo , Cristalografia por Raios X , Guaiacol/química , Guaiacol/metabolismo , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Modelos Moleculares , Mioglobina/metabolismo , Oxirredução , Peroxidases/metabolismo , Ácidos Sulfônicos/química , Ácidos Sulfônicos/metabolismo , Tirosina/metabolismo
5.
Anal Chim Acta ; 1105: 162-168, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32138915

RESUMO

Nanozymes, or nanomaterials that mimic the behaviors of enzymes, are highly promising materials for biomedical applications because of their excellent chemical stability under harsh conditions, simple preparation method and lower costs compared with natural enzymes. We herein report the intrinsic oxidase-mimicking activity of molybdenum oxide nanoparticles (MoO3 NPs). MoO3 NPs catalyzed the oxidation of colorless 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) to green product. The catalytic mechanism of the oxidase-mimicking activity of the MoO3 NPs was investigated in detail using electron spin resonance and a radical inhibition method. The oxidation of ABTS stems from 1O2 generated from the interaction between MoO3 NPs and dissolved oxygen in the solution. Acid phosphatase (ACP) catalyzes the hydrolysis of the ascorbic acid 2-phosphate (AAP) substrate to produce ascorbic acid (AA). AA was found to fade the coloration process of the MoO3 NP-mediated ABTS oxidation. By combining the oxidase-mimicking property of the MoO3 NPs and the ACP-catalyzed hydrolysis of AAP, a novel and simple colorimetric method for detecting ACP was established. The linear range for ACP determination is 0.09-7.3 U/L with a detection limit of 0.011 U/L. This new colorimetric method was successfully applied to the detection of ACP in diluted human serum samples and screening of ACP inhibitors. The present study proposes MoO3 NPs as a new oxidase mimic for establishing various biosensing method.


Assuntos
Fosfatase Ácida/análise , Técnicas Biossensoriais , Colorimetria , Molibdênio/química , Nanopartículas/química , Óxidos/química , Fosfatase Ácida/antagonistas & inibidores , Fosfatase Ácida/metabolismo , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/química , Ácido Ascórbico/metabolismo , Benzotiazóis/química , Benzotiazóis/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Molibdênio/metabolismo , Nanopartículas/metabolismo , Oxirredução , Óxidos/metabolismo , Tamanho da Partícula , Ácidos Sulfônicos/química , Ácidos Sulfônicos/metabolismo , Propriedades de Superfície
6.
Enzyme Microb Technol ; 135: 109507, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32146934

RESUMO

The azo dye Congo red is heavily used in textile industries and is actively present in the wastewater run-offs. Its structural complexity and physical characteristics make it resistant to the physicochemical treatments employed by the industry. Over time, application of the enzyme laccase has proved to be quite useful due to its ability to oxidize and eventually decolorize the dye. Moreover, the use of ABTS as the electron mediator also helps in enhancing the oxidizing capability of the enzyme with congo red. The present study involves establishing the role of the individual components i.e. laccase, ABTS and the dye, in the LMS electrochemically. Congo red doesn't have any form of electrochemical activity by itself, but the enzyme brings about a substantial change by increasing the rate of reduction. The effect of ABTS, though same, is concentration-dependent. For LMS, laccase helps in bringing about the rate of reduction much faster in the presence of the mediator, initiating the decolorization of the dye.


Assuntos
Vermelho Congo/metabolismo , Proteínas Fúngicas/metabolismo , Lacase/metabolismo , Trametes/metabolismo , Compostos Azo/química , Compostos Azo/metabolismo , Benzotiazóis/metabolismo , Biodegradação Ambiental , Proteínas Fúngicas/química , Cinética , Lacase/química , Ácidos Sulfônicos/metabolismo , Trametes/química , Trametes/enzimologia
7.
Biochem Biophys Res Commun ; 518(4): 685-690, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31472963

RESUMO

Peroxiredoxins (Prxs) detoxify hydrogen peroxide (H2O2), peroxynitrite, and various organic hydroperoxides. However, the differential oxidative status of Prxs reacted with each peroxide remains unclear. In the present study, we focused on the oxidative alteration of Prxs and demonstrated that, in human red blood cells (RBCs), peroxiredoxin 2 (Prx2) is readily reactive with H2O2, forming disulfide dimers, but was not easily hyperoxidized. In contrast, Prx2 was highly sensitive to the relatively hydrophobic oxidants, such as tert-butyl hydroperoxide (t-BHP) and cumene hydroperoxide. These peroxides hyperoxidized Prx2 into oxidatively damaged forms in RBCs. The t-BHP treatment formed hyperoxidized Prx2 in a dose-dependent manner. When organic hydroperoxide-treated RBC lysates were subjected to reverse-phase high performance liquid chromatography, two peaks derived from hyperoxidized Prx2 appeared along with the decrease of that corresponding to native Prx2. Liquid chromatography-tandem mass spectrometry analysis clearly showed that hyperoxidation to sulfonic acid (-SO3H) at Cys-51 residue was more advanced in a newfound hyperoxidized Prx2 compared to another hydrophobic hyperoxidized form previously identified. These results indicate that irreversible hyperoxidation of the Prx2 monomer in RBCs was easily caused by organic hydroperoxide but not H2O2. Thus, it is important to detect the hyperoxidation of Prx2 into sulfinic or sulfonic acid derivates of Cys-51 because hyperoxidized Prx2 is a potential marker of oxidative injury caused by organic hydroperoxides in human RBCs.


Assuntos
Eritrócitos/metabolismo , Peróxido de Hidrogênio/metabolismo , Peróxidos/metabolismo , Peroxirredoxinas/metabolismo , Adulto , Cromatografia de Fase Reversa , Cisteína/química , Cisteína/metabolismo , Dissulfetos/química , Dissulfetos/metabolismo , Humanos , Peróxido de Hidrogênio/química , Pessoa de Meia-Idade , Oxidantes/química , Oxidantes/metabolismo , Oxirredução , Peróxidos/química , Peroxirredoxinas/química , Ácidos Sulfínicos/química , Ácidos Sulfínicos/metabolismo , Ácidos Sulfônicos/química , Ácidos Sulfônicos/metabolismo , Adulto Jovem , terc-Butil Hidroperóxido/química , terc-Butil Hidroperóxido/metabolismo
8.
Nat Microbiol ; 4(10): 1706-1715, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31332382

RESUMO

In the surface ocean, phytoplankton transform inorganic substrates into organic matter that fuels the activity of heterotrophic microorganisms, creating intricate metabolic networks that determine the extent of carbon recycling and storage in the ocean. Yet, the diversity of organic molecules and interacting organisms has hindered detection of specific relationships that mediate this large flux of energy and matter. Here, we show that a tightly coupled microbial network based on organic sulfur compounds (sulfonates) exists among key lineages of eukaryotic phytoplankton producers and heterotrophic bacterial consumers in the North Pacific Subtropical Gyre. We find that cultured eukaryotic phytoplankton taxa produce sulfonates, often at millimolar internal concentrations. These same phytoplankton-derived sulfonates support growth requirements of an open-ocean isolate of the SAR11 clade, the most abundant group of marine heterotrophic bacteria. Expression of putative sulfonate biosynthesis genes and sulfonate abundances in natural plankton communities over the diel cycle link sulfonate production to light availability. Contemporaneous expression of sulfonate catabolism genes in heterotrophic bacteria highlights active cycling of sulfonates in situ. Our study provides evidence that sulfonates serve as an ecologically important currency for nutrient and energy exchange between microbial autotrophs and heterotrophs, highlighting the importance of organic sulfur compounds in regulating ecosystem function.


Assuntos
Bactérias/metabolismo , Eucariotos/metabolismo , Consórcios Microbianos , Fitoplâncton/metabolismo , Água do Mar/microbiologia , Ácidos Sulfônicos/metabolismo , Processos Autotróficos , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Ritmo Circadiano , Eucariotos/classificação , Eucariotos/genética , Eucariotos/isolamento & purificação , Processos Heterotróficos , Luz , Redes e Vias Metabólicas/genética , Oceano Pacífico , Fitoplâncton/classificação , Fitoplâncton/genética , Água do Mar/química , Ácidos Sulfônicos/química
9.
Int J Med Microbiol ; 309(7): 151324, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31278055

RESUMO

The MmcO protein of Mycobacterium tuberculosis is a membrane-associated multicopper oxidase. Its natural substrate(s) and its role in pathogenesis are not well characterized. A recent report proposes that MmcO contributes to copper resistance in M. tuberculosis during infection. We have expressed and reconstituted the active enzyme from inclusion bodies in E. coli. MmcO exhibits maximal activity against the experimental substrate 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) or ABTS, at pH 4. The enzyme also exhibits ferroxidase activity at pH 4. Most notable was the finding that MmcO is able to scavenge the reactive oxygen species (ROS) generated by the xanthine/xanthine oxidase enzyme system. This ROS scavenging activity of MmcO was also evident against ROS generated by THP-1 cells. We propose that MmcO protects M. tuberculosis during infection against ROS attack in addition to providing copper resistance to the pathogen.


Assuntos
Proteínas de Bactérias/metabolismo , Ceruloplasmina/metabolismo , Cobre/metabolismo , Mycobacterium tuberculosis/enzimologia , Oxirredutases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Benzotiazóis/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Mycobacterium tuberculosis/genética , Oxirredutases/química , Oxirredutases/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Ácidos Sulfônicos/metabolismo , Células THP-1
10.
J Clin Endocrinol Metab ; 104(10): 4651-4659, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31169903

RESUMO

CONTEXT: N-glycosylation and glycan composition of human TSH molecules modulate the biological properties of TSH in different physiological and clinical situations. The degree of sialylation of serum TSH was reported to be very low in normal third-trimester fetuses compared with normal adults. The circulating TSH glycoforms and their glycan compositions in young children have hitherto not been determined. OBJECTIVE: To characterize N-glycosylation and glycan composition of circulating TSH molecules in young children. DESIGN, PARTICIPANTS, MAIN OUTCOME MEASURES: Serum samples were obtained from euthyroid individuals: 33 children, age 2 weeks to 3 years, and 264 adults. The di-glycosylated TSH and tri-glycosylated TSH glycoforms were determined and characterized with respect to sialylation and sulfonation. The TSH N-glycosylation was also examined in pituitary extracts of 75 individuals. RESULTS: In children up to 18 months of age, most TSH molecules were low-N-glycosylated, high-sulfonated, and low-sialylated compared with older children and adults. The degree of N-glycosylation was similar in serum and pituitary extracts up to 3 months of age and after that was higher in serum than in pituitary extracts. CONCLUSIONS: Children up to age 18 months had low-sialylated TSH molecules, similar to those reported for third-trimester fetuses. Most TSH molecules in young children were of smaller size and less negatively charged, favoring transport into their target tissues. The low sialylation favors a high biopotency at thyroid and extrathyroidal TSH receptors. A delayed development of the liver SO3-N-acetylgalactosamine receptor function after birth is a likely explanation of the highly sulfonated TSH molecules in serum samples of infants.


Assuntos
Ácido N-Acetilneuramínico/metabolismo , Hipófise/metabolismo , Polissacarídeos/metabolismo , Ácidos Sulfônicos/metabolismo , Tireotropina/metabolismo , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Glicosilação , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Modificação Traducional de Proteínas , Processamento de Proteína Pós-Traducional , Tireotropina/química , Adulto Jovem
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 219: 358-366, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31055242

RESUMO

Caffeic acid (CA) is a plant metabolite acting as a carcinogenic inhibitor, and exhibits a high antioxidant effect and some antimicrobial activity. Besides, this compound can be useful in the prevention of heart diseases and atherosclerosis, among others. The present study aims to determine the in vitro antioxidant activity of CA in order to increase the frequency of its use and reliability in the prevention of damage caused by free radicals and other reactive species. The tests performed were as follows: Radical anion superoxide capture; crocin bleaching assay; capturing ability of hypochlorous acid; H2O2 capture; capturing capacity of the ABTS•+/DPPH•; and SOD-like activity. The values of the CA antioxidant activity were very close to the values of standards in all tests. Besides, CA presented an antioxidant activity greater than that of ascorbic acid and trolox, and its advantages include higher stability than ascorbic acid and extraction from natural sources, as opposed to trolox.


Assuntos
Antioxidantes/farmacologia , Ácidos Cafeicos/farmacologia , Ácido Ascórbico/farmacologia , Benzotiazóis/metabolismo , Compostos de Bifenilo/metabolismo , Cromanos/farmacologia , Radicais Livres/metabolismo , Peróxido de Hidrogênio/metabolismo , Ácido Hipocloroso/metabolismo , Picratos/metabolismo , Ácidos Sulfônicos/metabolismo , Superóxidos/metabolismo
12.
J Cell Biochem ; 120(10): 17015-17029, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31125141

RESUMO

Diabetic macular edema, also known as diabetic eye disease, is mainly caused by the overexpression of vascular endothelial protein tyrosine phosphatase (VE-PTP) at hypoxia/ischemic. AKB-9778 is a known VE-PTP inhibitor that can effectively interact with the active site of VE-PTP to inhibit the activity of VE-PTP. However, the binding pattern of VE-PTP with AKB-9778 and the dynamic implications of AKB-9778 on VE-PTP system at the molecular level are poorly understood. Through molecular docking, it was found that the AKB-9778 was docked well in the binding pocket of VE-PTP by the interactions of hydrogen bond and Van der Waals. Furthermore, after molecular dynamic simulations on VE-PTP system and VE-PTP AKB-9778 system, a series of postdynamic analyses found that the flexibility and conformation of the active site undergone an obvious transition after VE-PTP binding with AKB-9778. Moreover, by constructing the RIN, it was found that the different interactions in the active site were the detailed reasons for the conformational differences between these two systems. Thus, the finding here might provide a deeper understanding of AKB-9778 as VE-PTP Inhibitor.


Assuntos
Compostos de Anilina/química , Inibidores Enzimáticos/química , Hipoglicemiantes/química , Simulação de Acoplamento Molecular , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores/química , Ácidos Sulfônicos/química , Motivos de Aminoácidos , Compostos de Anilina/metabolismo , Domínio Catalítico , Inibidores Enzimáticos/metabolismo , Humanos , Ligação de Hidrogênio , Hipoglicemiantes/metabolismo , Cinética , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores/antagonistas & inibidores , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores/metabolismo , Ácidos Sulfônicos/metabolismo , Termodinâmica
13.
J Pharmacol Exp Ther ; 369(3): 389-405, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30918069

RESUMO

Lithocholic acid (LCA) is a bile acid associated with adverse effects, including cholestasis, and it exists in vivo mainly as conjugates known as glyco-LCA (GLCA) and tauro-LCA (TLCA). Tamoxifen has been linked to the development of cholestasis, and it inhibits sulfotransferase 2A1 (SULT2A1)-catalyzed dehydroepiandrosterone (DHEA) sulfonation. The present study was done to characterize the sulfonation of LCA, GLCA, and TLCA and to investigate whether triphenylethylene (clomifene, tamoxifen, toremifene, ospemifene, droloxifene), benzothiophene (raloxifene, arzoxifene), tetrahydronaphthalene (lasofoxifene, nafoxidine), indole (bazedoxifene), and benzopyran (acolbifene) classes of selective estrogen receptor modulator (SERM) inhibit LCA, GLCA, and TLCA sulfonation. Human recombinant SULT2A1, but not SULT2B1b or SULT1E1, catalyzed LCA, GLCA, and TLCA sulfonation, whereas each of these enzymes catalyzed DHEA sulfonation. LCA, GLCA, and TLCA sulfonation is catalyzed by human liver cytosol, and SULT2A1 followed the substrate inhibition model with comparable apparent K m values (≤1 µM). Each of the SERMs inhibited LCA, GLCA, and TLCA sulfonation with varying potency and mode of enzyme inhibition. The potency and extent of inhibition of LCA sulfonation were attenuated or increased by structural modifications to toremifene, bazedoxifene, and lasofoxifene. The inhibitory effect of raloxifene, bazedoxifene, and acolbifene on LCA sulfonation was also observed in HepG2 human hepatocellular carcinoma cells. Overall, among the SERMs investigated, bazedoxifene and raloxifene were the most effective inhibitors of LCA, GLCA, and TLCA sulfonation. These findings provide insight into the structural features of specific SERMs that contribute to their inhibition of SULT2A1-catalyzed LCA sulfonation. Inhibition of LCA, GLCA, and TLCA detoxification by a SERM may provide a biochemical basis for adverse effects associated with a SERM.


Assuntos
Biocatálise/efeitos dos fármacos , Ácido Litocólico/análogos & derivados , Moduladores Seletivos de Receptor Estrogênico/química , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Ácidos Sulfônicos/metabolismo , Sulfotransferases/metabolismo , Ácido Taurolitocólico/metabolismo , Citosol/efeitos dos fármacos , Citosol/metabolismo , Células Hep G2 , Humanos , Cinética , Ácido Litocólico/metabolismo , Fígado/citologia , Oxirredução , Moduladores Seletivos de Receptor Estrogênico/metabolismo , Sulfotransferases/antagonistas & inibidores
14.
J Am Chem Soc ; 141(13): 5121-5124, 2019 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-30869886

RESUMO

Malonyl-thioesters are reactive centers of malonyl-CoA and malonyl- S-acyl carrier protein, essential to fatty acid, polyketide and various specialized metabolite biosynthesis. Enzymes that create or use malonyl-thioesters spontaneously hydrolyze or decarboxylate reactants on the crystallographic time frame preventing determination of structure-function relationships. To address this problem, we have synthesized a panel of methylmalonyl-CoA analogs with the carboxylate represented by a sulfonate or nitro and the thioester retained or represented by an ester or amide. Structures of Escherichia coli methylmalonyl-CoA decarboxylase in complex with our analogs affords insight into substrate binding and the catalytic mechanism. Counterintuitively, the negatively charged sulfonate and nitronate functional groups of our analogs bind in an active site hydrophobic pocket. Upon decarboxylation the enolate intermediate is protonated by a histidine preventing CO2-enolate recombination, yielding propionyl-CoA. Activity assays support a histidine catalytic acid and reveal the enzyme displays significant hydrolysis activity. Our structures also provide insight into this hydrolysis activity. Our analogs inhibit decarboxylation/hydrolysis activity with low micromolar Ki values. This study sets precedents for using malonyl-CoA analogs with carboxyate isosteres to study the complicated structure-function relationships of acyl-CoA carboxylases, trans-carboxytransferases, malonyltransferases and ß-ketoacylsynthases.


Assuntos
Ésteres/metabolismo , Metilmalonil-CoA Descarboxilase/química , Nitrocompostos/química , Compostos de Sulfidrila/metabolismo , Ácidos Sulfônicos/química , Ésteres/química , Metilmalonil-CoA Descarboxilase/metabolismo , Estrutura Molecular , Nitrocompostos/metabolismo , Estereoisomerismo , Compostos de Sulfidrila/química , Ácidos Sulfônicos/metabolismo
15.
Int J Mol Sci ; 20(4)2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30781644

RESUMO

Oxidative stress is the main pathogenesis of diabetic microangiopathy, which can cause microvascular endothelial cell damage and destroy vascular barrier. In this study, it is found that carnosol protects human microvascular endothelial cells (HMVEC) through antioxidative mechanisms. First, we measured the antioxidant activity of carnosol. We showed that carnosol pretreatment suppressed tert-butyl hydroperoxide (t-BHP)-induced cell viability, affected the production of lactate dehydrogenase (LDH) as well as reactive oxygen species (ROS), and increased the produce of nitric oxide (NO). Additionally, carnosol promotes the protein expression of vascular endothelial cadherin (VE-cadherin) to keep the integrity of intercellular junctions, which indicated that it protected microvascular barrier in oxidative stress. Meanwhile, we investigated that carnosol can interrupt Nrf2-Keap1 protein-protein interaction and stimulated antioxidant-responsive element (ARE)-driven luciferase activity in vitro. Mechanistically, we showed that carnosol promotes the expression of heme oxygenase 1(HO-1) and nuclear factor-erythroid 2 related factor 2(Nrf2). It can also promote the expression of endothelial nitric oxide synthase (eNOS). Collectively, our data support the notion that carnosol is a protective agent in HMVECs and has the potential for therapeutic use in the treatments of microvascular endothelial cell injury.


Assuntos
Abietanos/farmacologia , Antioxidantes/farmacologia , Células Endoteliais/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Abietanos/química , Antígenos CD/metabolismo , Benzotiazóis/metabolismo , Caderinas/metabolismo , Linhagem Celular , Citoproteção/efeitos dos fármacos , Citoproteção/genética , Células Endoteliais/efeitos dos fármacos , Sequestradores de Radicais Livres/metabolismo , Humanos , Microvasos/patologia , Simulação de Acoplamento Molecular , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ácidos Sulfônicos/metabolismo , terc-Butil Hidroperóxido
16.
BMC Complement Altern Med ; 19(1): 30, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30691451

RESUMO

BACKGROUND: Exposure of skin to urban air pollutants is closely related to skin aging and inflammatory responses such as wrinkles formation, pigmentation spot, atopic dermatitis, and acne. Thus, a great deal of interest has been focused on the development of natural resources that can provide a protective effect to skin from pollutants. METHODS: The antioxidative activity of Camellia japonica flower extract (CJFE) was evaluated by 1,2-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assay, and the inhibitory effect of CJFE by urban air pollutants-induced reactive oxygen species (ROS) production was determined in cultured normal human dermal fibroblasts (NHDFs). We additionally investigated the protective effects of CJFE against urban air pollutant using in vitro and ex vivo model. RESULTS: CJFE with high phenolic concentration showed antioxidative activity on scavenging capacity of 1,2-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation in a concentration dependent manner. CJFE inhibited urban air pollutants-induced ROS generation, matrixmetalloproteinase-1 (MMP-1) production and a xenobiotic response element (XRE)-luciferase activity indicating the aryl hydrocarbon receptor (AhR) transactivation. In addition, CJFE showed an excellent protective activity against pollutants-induced deteriorating effect in ex vivo model. CJFE reduced the level of pollutants-induced malondialdehyde (MDA), lipid peroxidation marker, inhibited MMP-1 expression and increased collagen synthesis. It also reduced the cell numbers with pyknotic nuclei (mainly occurring in apoptosis) and detachment of dermo-epidermal junction (DEJ) induced by pollutants. CONCLUSIONS: Apparently, it is proposed that CJFE can be used as a protective material against pollutant-induced skin damages.


Assuntos
Poluentes Atmosféricos/toxicidade , Camellia/química , Flores/química , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Benzotiazóis/metabolismo , Compostos de Bifenilo/metabolismo , Células Cultivadas , Fibroblastos/efeitos dos fármacos , Humanos , Oxirredução/efeitos dos fármacos , Picratos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ácidos Sulfônicos/metabolismo
17.
Colloids Surf B Biointerfaces ; 175: 671-679, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30590328

RESUMO

In this research we report the biological synthesis of electrically conducting polymer - Polypyrrole (Ppy). Cell-assisted enzymatic polymerization/oligomerization of Ppy was achieved using whole cell culture and cell-free crude enzyme extract from two white-rot fungal cultures. The selected fungal strains belong to Trametes spp., known laccase producers, commonly applied in bioremediation and bioelectrochemical fields. The biocatalytic reaction was initiated in situ through the copper-containing enzymes biosynthesized within the cell cultures under submerged aerobe cultivation conditions. The procedure was inspired by successful reports of laccase-catalyzed pyrrole polymerization. The usage of whole culture and/or crude enzyme extract has the advantage of overcoming enzyme purification and minimizing the liability of enzyme inactivation through improved stability of enzymes in their natural environment. Spectral and electrochemical techniques (UV-vis spectroscopy, infrared spectroscopy; cyclic voltammetry (CV)) and pH measurements provided insight into the evolution of pyrrole polymerization/oligomerization and the electrochemical features of the final product. Microscopy techniques (optical microscopy and scanning electron microscopy (SEM)) were primary tools for visualization of the formed Ppy particles. The relevance of our research is twofold: Ppy prepared in crude enzyme extract results in enzyme encapsulated within Ppy and/or Ppy-modified fungal cells can be formed when polymerization occurs in whole cell culture. The route of biocatalysis can be chosen according to the desired bioelectrochemical application. The reported study focuses on the improvement of charge transfer through the fungal cell membrane and/or cell wall by modification of the fungal cells with conducting polymer - polypyrrole.


Assuntos
Proteínas Fúngicas/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Polímeros/metabolismo , Pirróis/metabolismo , Trametes/metabolismo , Benzotiazóis/metabolismo , Benzotiazóis/farmacologia , Biocatálise , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Meios de Cultura/química , Meios de Cultura/farmacologia , Condutividade Elétrica , Técnicas Eletroquímicas , Fermentação/efeitos dos fármacos , Guaiacol/metabolismo , Guaiacol/farmacologia , Hidrazonas/metabolismo , Hidrazonas/farmacologia , Concentração de Íons de Hidrogênio , Polímeros/química , Pirróis/química , Ácidos Sulfônicos/metabolismo , Ácidos Sulfônicos/farmacologia , Trametes/efeitos dos fármacos
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 208: 243-254, 2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30342339

RESUMO

Due to the high sensitivity to alterations in microenvironment polarity of macromolecules, pyrene and its derivatives have long been applied in biosciences. Human serum albumin (HSA), besides its numerous physiological functions, is the main responsible by transport of endogenous and exogenous compounds in the circulatory system. Here, a comprehensive study was carry out to understand the interaction between HSA and the pyrene derivative 1-pyrenesulfonic acid (PMS), which showed a singular behaviour when bound to this protein. The complexation of PMS with HSA was studied by steady state, time-resolved and anisotropy fluorescence, induction of circular dichroism (ICD) and molecular docking. The fluorescence quenching of PMS by HSA was abnormal, being stronger at lower concentration of the quencher. Similar behaviour was obtained by measuring the ICD signal and fluorescence lifetime of PMS complexed in HSA. The displacement of PMS by site-specific drugs showed that this probe occupied both sites, but with higher affinity for site II. The movement of PMS between these main binding sites was responsible by the abnormal effect. Using the holo (PDB: ID 1A06) and apo (PDB: ID 1E7A) HSA structures, the experimental results were corroborated by molecular docking simulation. The abnormal spectroscopic behaviour of PMS is related to its binding in different regions in the protein. The movement of PMS into the protein can be traced by alteration in the spectroscopic signals. These findings bring a new point of view about the use of fluorescence quenching to characterize the interaction between albumin and ligands.


Assuntos
Conalbumina/metabolismo , Pirenos/metabolismo , Soroalbumina Bovina/metabolismo , Albumina Sérica Humana/metabolismo , Ácidos Sulfônicos/metabolismo , Animais , Anisotropia , Sítios de Ligação , Bovinos , Dicroísmo Circular , Fluorescência , Humanos , Simulação de Acoplamento Molecular , Pirenos/química , Ácidos Sulfônicos/química , Termodinâmica , Fatores de Tempo , Triptofano/análogos & derivados , Triptofano/química
19.
Sci Total Environ ; 650(Pt 2): 2697-2704, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30296776

RESUMO

In this study, eggs from free-range and barn chickens in farms around a fluorochemical facility were collected to assess the distribution profiles of perfluoroalkyl acids (PFAAs), including isomers of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonate (PFHxS), in egg yolk and albumen. The results revealed that the concentrations of PFAAs in yolks were significantly higher than those in albumen. All 17 PFAAs examined could be detected in yolks, showing decreasing concentrations with increasing distance from the fluorochemical facility. The three predominant compounds in yolks were perfluorobutanoic acid (PFBA, mean concentration 81.4 ng/g ww), PFOS (28.0 ng/g ww), and PFOA (4.83 ng/g ww), and this result is consistent with the product structure of the facility. Moreover, n-PFOA, n-PFOS, and n-PFHxS were the dominant contaminants in yolk, with mean concentrations of 4.75, 25.7, and 4.29 ng/g ww, respectively. In albumen, PFBA was still the predominant PFAA congener (mean concentration = 3.93 ng/g ww), followed by PFOA. Docking analysis indicated that the PFAAs presented higher binding abilities with the low density lipoprotein, high density lipoprotein, and vitellin proteins in yolk than that with ovalbumin albumen proteins, which might be the main factor influencing the possible difference in distributions of PFAAs in yolk and albumen.


Assuntos
Ácidos Alcanossulfônicos/metabolismo , Caprilatos/metabolismo , Clara de Ovo/química , Gema de Ovo/química , Exposição Ambiental , Poluentes Ambientais/metabolismo , Fluorcarbonetos/metabolismo , Ácidos Sulfônicos/metabolismo , Animais , Galinhas , China , Monitoramento Ambiental
20.
Sci Total Environ ; 654: 19-27, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30428410

RESUMO

Organic compounds could be taken up by plants via different pathways, depending on chemical properties and biological species, which is important for the risk assessment and risk control. To investigate the transport pathways of perfluoroalkyl acids (PFAAs) by wheat (Triticum acstivnm L.), the uptake of five perfluoroalkyl carboxylic acids (PFCAs): TFA (C2), PFPrA (C3), PFBA (C4), PFHxA (C6), PFOA (C8), and a perfluoroalkyl sulfonic acid: PFOS (C8)) were studied using hydroponic experiments. Various inhibitors including a metabolic inhibitor (Na3VO4), two anion channel blockers (9-AC, DIDS), and two aquaporin inhibitors (AgNO3, glycerol) were examined. The wheat root and shoot showed different concentration trends with the carbon chain length of PFAAs. The uptake of TFA was inhibited by Na3VO4 and 9-AC whereas PFPrA was inhibited by Na3VO4, AgNO3 and 9-AC. For the other four PFAAs, only Na3VO4 was effective. These results together with the result of concentration-dependent uptake, which followed the Michaelis-Menten model, indicate that the uptake of PFAAs by wheat is mainly an energy-dependent active process mediated by carriers. For the ultra-short chain PFCAs (C2 and C3), aquaporins and anion channels may also be involved. A competition between TFA and PFPrA was determined during the plant uptake but no competition was observed between these two shorter chain analogues with other analogues, neither between PFBA and PFHxA, PFBA and PFBS, PFOA and PFOS.


Assuntos
Fluorcarbonetos/metabolismo , Plântula/metabolismo , Poluentes do Solo/metabolismo , Triticum/metabolismo , Poluentes Químicos da Água/metabolismo , Ácidos Carboxílicos/análise , Ácidos Carboxílicos/metabolismo , Relação Dose-Resposta a Droga , Fluorcarbonetos/análise , Plântula/crescimento & desenvolvimento , Poluentes do Solo/análise , Ácidos Sulfônicos/análise , Ácidos Sulfônicos/metabolismo , Fatores de Tempo , Triticum/crescimento & desenvolvimento , Poluentes Químicos da Água/análise
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