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1.
Food Chem ; 338: 127834, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32810810

RESUMO

The use of starters during fermentation has been gaining momentum as it can warrant high-quality chocolate. The objective of this study was to investigate the influence of Saccharomyces cerevisiae (Sc) and Pichia kudriavzevii (Pk) during on-farm fermentation on physico-chemical and microbiological characteristics and levels of methylxanthines and bioactive amines of cocoa. Four treatments were used: ScPk (1:1), only Sc, only Pk, and no starter (control). The starters lead to changes throughout fermentation, but provided fermented cocoa with similar pH, titratable acidity, reducing sugars and phenolic compounds. ScPk shortened fermentation time by 24 h. The ScPk fermented and dried cocoa had higher levels of monomeric phenols, methylxanthines, phenylethylamine and lower levels of the putrefactive amines - putrescine and cadaverine (p < 0.05). The results were confirmed by multivariate analysis. Based on these results, the mixture of both yeasts species is a promising starter for cocoa fermentation decreasing duration time and modulating high-quality components.


Assuntos
Cacau/química , Cacau/microbiologia , Chocolate/microbiologia , Pichia , Saccharomyces cerevisiae , Aminas/metabolismo , Cafeína/análise , Catequina/análise , Fazendas , Fermentação , Microbiologia de Alimentos , Concentração de Íons de Hidrogênio , Fenóis/análise , Temperatura , Teobromina/análise , Teofilina/análise , Fatores de Tempo
2.
Food Chem ; 336: 127551, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32795783

RESUMO

The inhibitory effects of Portulaca oleracea L. (PO) and its flavonoid ingredients on the formation of heterocyclic amines (HAs) in roast beef patties were investigated. Ten HAs were found in control patties, and the total content was 212.73 ± 7.13 ng/g. With the addition of PO (1%, 5%, and 10%, w/w), HAs decreased by 62.39%, 68.03%, and 73.75%, respectively. The main flavonoid ingredients (rutin, hesperidin, and flavanone) also present a similar inhibitory effect. The Density Function Theory (DFT) methods were adopted to investigate the inhibitory mechanism. These ingredients bonded with the intermediate to block the formation of norharman. Both experimental and calculated data of the ingredients were analyzed on their HAs inhibitory capacity. Our results provide a novel and valuable strategy to reduce HAs via a low additive level of medicinal and edible plants. And the correlation between experimental and calculated data could be applied to predict the inhibitory ability of inhibitors.


Assuntos
Aminas/química , Flavonoides/química , Portulaca/química , Carne Vermelha/análise , Aminas/análise , Aminas/metabolismo , Animais , Antioxidantes/química , Bovinos , Cromatografia Líquida de Alta Pressão , Teoria da Densidade Funcional , Compostos Heterocíclicos/química , Portulaca/metabolismo , Espectrometria de Massas em Tandem
3.
Nat Commun ; 11(1): 4722, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948764

RESUMO

Precisely controlled deuterium labeling at specific sites of N-alkyl drugs is crucial in drug-development as over 50% of the top-selling drugs contain N-alkyl groups, in which it is very challenging to selectively replace protons with deuterium atoms. With the goal of achieving controllable isotope-labeling in N-alkylated amines, we herein rationally design photocatalytic water-splitting to furnish [H] or [D] and isotope alkanol-oxidation by photoexcited electron-hole pairs on a polymeric semiconductor. The controlled installation of N-CH3, -CDH2, -CD2H, -CD3, and -13CH3 groups into pharmaceutical amines thus has been demonstrated by tuning isotopic water and methanol. More than 50 examples with a wide range of functionalities are presented, demonstrating the universal applicability and mildness of this strategy. Gram-scale production has been realized, paving the way for the practical photosynthesis of pharmaceuticals.


Assuntos
Aminas/química , Aminas/metabolismo , Luz , Semicondutores , Alquilação , Aminas/farmacologia , Catálise , Deutério , Oxirredução , Preparações Farmacêuticas , Prótons , Água , Difração de Raios X
4.
Xenobiotica ; 50(11): 1341-1351, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32501166

RESUMO

The specialty amine catalyst 2,2'-dimorpholinodiethyl ether (DMDEE) is a high-production volume chemical used in the production of flexible foam, high-resilient molded foam, and in coatings and adhesives. The disposition and metabolism of [14C]DMDEE (20 or 200 mg/kg) were determined in male ane female rats and mice after oral and intravenous administration and dermal application. In male and female rats, following a single oral administration, [14C]DMDEE was well-absorbed and excreted rapidly and extensively via urine (75-93%) and some in feces (∼4-8%). The total radioactivity in tissues at 24 h and 72 h (males only) following oral administration was 8-10% and ∼4%, respectively, suggesting considerable tissue distribution. A moderate amount of the total tissue radioactivity in kidney and liver were unextractable suggesting covalent binding of [14C]DMDEE-derived products in tissue macromolecules. Absorption following a single dermal application in rats was significant (∼64%) with a similar disposition pattern to oral. The oral and dermal disposition of [14C]DMDEE in male and female mice was similar to rats. Urinary products of DMDEE identified were oxidative metabolism of the morpholine ring. Coadministration of DMDEE with nitrite in rats didn't produce the rodent carcinogen, N-nitrosomorpholine.


Assuntos
Aminas/metabolismo , Administração Cutânea , Administração Intravenosa , Administração Oral , Animais , Feminino , Fígado , Masculino , Camundongos , Camundongos Endogâmicos , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
5.
J Biotechnol ; 318: 39-44, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32413366

RESUMO

Stabilization of dimeric enzymes requires the stabilization of the quaternary structure as well as the 3D one. Both subunits may be easily immobilized on a highly activated support. Additional stabilization of the 3D structure may be achieved via multipoint covalent attachment (MCA) on highly activated supports. In the case of monomeric enzymes or thermophilic dimeric ones, the optimal stabilization is obtained via the most intense MCA and it is associated to a small loss of catalytic activity. However, in the case of mesophilic enzymes, a very intense MCA of both subunits may promote negative effects, e.g., associated to distortions of the assembly between subunits and a subsequent very important loss of catalytic activity. A dimeric mesophilic amine oxidase from P.sativum was stabilized by MCA on glyoxyl-agarose. Both subunits were covalently immobilized on the support through the region with the highest density in Lys residues. In addition to that, an interesting activity/stabilization binomial was obtained after only 3 h of enzyme-support multiinteraction (50 % of activity/350 fold stabilization). However, after 24 h of enzyme-support multi-interaction this binomial activity-stabilization decreased down to 30/150. A moderate multiinteraction seems to be the optimal strategy for immobilization-stabilization of mesophilic dimeric enzymes and it promotes moderate losses of activity and interesting stabilizations against the combined effect of heat, acid pH and ethanol. The control of the intensity of enzyme-support multi-interactions becomes now strictly necessary.


Assuntos
Aminas , Enzimas Imobilizadas/química , Oxirredutases/química , Ervilhas/enzimologia , Aminas/metabolismo , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Etanol/química , Glioxilatos/química , Concentração de Íons de Hidrogênio , Oxirredutases/metabolismo , Estrutura Quaternária de Proteína , Subunidades Proteicas , Sefarose/química , Temperatura , Fatores de Tempo
6.
J Food Sci ; 85(4): 1361-1370, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32147842

RESUMO

The effects of surface application of amino acids on the formation of heterocyclic amines (HCAs) and meat quality properties were evaluated in pan-fried beef patties (230 °C/15 min). Tryptophan, lysine, leucine, and proline at three concentrations, 0.05%, 0.20%, and 0.50% (w/w), were tested. The meat crusts were analyzed for HCA content using liquid chromatography-tandem mass spectrometry. Results showed that surface application of all tested amino acids significantly reduced total HCA content (P < 0.05), and the interaction of amino acid type and concentration significantly affected (P < 0.05) both individual and total HCA formation. Tryptophan at 0.50% reduced total HCAs the most (0.92 ng/g, 93% inhibition), followed by 0.50% lysine (1.94 ng/g, 84% inhibition), while leucine (3.95 ng/g, 64% inhibition) and proline (4.71 ng/g, 56% inhibition) were less effective at 0.50%. In addition, applying amino acids to meat surface significantly influenced (P < 0.05) pH and surface color change of beef crusts; particularly, lysine at 0.20% and 0.50% increased pH and a* (redness) but reduced b* (yellowness), while tryptophan and leucine at 0.50% increased L* (whiteness). No significant effect was observed on cooking loss. Adding amino acids at 0.50% affected (P < 0.05) formation of aldehydes and pyrazines (as the key flavor compounds of fried beef). Overall, the results of this study suggested that adding amino acids to ground beef patties could effectively mitigate mutagenic HCA formation during cooking.


Assuntos
Aminas/metabolismo , Aminoácidos/administração & dosagem , Culinária/métodos , Carne Vermelha/análise , Aminas/química , Aminoácidos/química , Animais , Bovinos , Cromatografia Líquida , Compostos Heterocíclicos , Mutagênicos/análise , Extratos Vegetais/farmacologia
7.
Appl Microbiol Biotechnol ; 104(7): 2999-3009, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32064550

RESUMO

ω-Transaminase (ω-TA) is an attractive alternative to metal catalysts for the stereoselective amination of prochiral ketones. The narrow substrate scope of an R-ω-transaminase from Mycobacterium vanbaalenii (MvTA) limits its application in R-amine synthesis. A fluorescence-based TA activity screening system was developed to extend its substrate scope. The reactions were conducted in microtiter plates (MTPs) and displayed low background interference, high sensitivity (µM magnitude), and a wide dynamic range (ɀ-factor > 0.9). A KnowVolution campaign was performed on this enzyme, and screening ~ 8000 clones with this fluorescence-based screening system resulted in two beneficial substitutions (G68Y and F129A) and three improved variants (M3, M4, and M5). The best variant, MvTA M5 (WT+G68Y+F129A), achieved the highest catalytic efficiency (toward fluorogenic substrate NMA) which was 3.2-fold higher than that of the WT enzyme. MvTA M5 exhibited significantly enhanced activity toward six different prochiral ketones with e.e. > 99% (R). The specific activity of MvTA M5 was more than 100 times higher than that of the WT enzyme toward acetonaphthone (M5: 8.1 U/mg, WT: ~ 0.07 U/mg), and it showed the highest activity on acetonaphthone, p-ethylacetophenone, and phenylacetone.


Assuntos
Ensaios de Triagem em Larga Escala/métodos , Transaminases/genética , Transaminases/metabolismo , Aminas/metabolismo , Substituição de Aminoácidos , Evolução Molecular Direcionada , Estabilidade Enzimática , Fluorescência , Cetonas/metabolismo , Cinética , Mycobacteriaceae/enzimologia , Mycobacteriaceae/genética , Mycobacteriaceae/metabolismo , Engenharia de Proteínas , Especificidade por Substrato
8.
Am J Clin Nutr ; 111(6): 1244-1251, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32077920

RESUMO

BACKGROUND: Red and processed meat, recognized carcinogens, are risk factors for colorectal neoplasia, including polyps, the precursor for colorectal cancer. The mechanism is unclear. One possible explanation is the mutagenic activity of these foods, perhaps due to generation during cooking [e.g., heterocyclic amine (HCA) intake]. Few studies have evaluated meat intake and sessile serrated lesion (SSL) risk, a recently recognized precursor, and no study has evaluated meat cooking methods and meat-derived mutagens with SSL risk. OBJECTIVE: We evaluated intakes of meat, meat cooking methods, and inferred meat mutagens with SSL risk and in comparison to risk of other polyps. METHODS: Meat, well-done meat, and inferred meat mutagen intakes were evaluated. Polytomous logistic regression models were used to estimate ORs and 95% CIs among cases (556 hyperplastic polyp, 1753 adenoma, and 208 SSL) and controls (3804) in the large colonoscopy-based, case-control study, the Tennessee Colorectal Polyp Study. RESULTS: The highest quartile intakes of red meat (OR: 2.38; 95% CI: 1.44, 3.93), processed meat (OR: 2.03; 95% CI: 1.30, 3.17), well-done red meat (OR: 2.19; 95% CI: 1.34, 3.60), and the HCA 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQX; OR: 2.48; 95% CI: 1.49, 4.16) were associated with increased risk of SSLs in comparison to the lowest quartile intake. CONCLUSIONS: High intakes of red and processed meats are strongly and especially associated with SSL risk and part of the association may be due to HCA intake. Future studies should evaluate other mechanism(s) and the potential for primary prevention.


Assuntos
Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Culinária/métodos , Exposição Dietética/efeitos adversos , Carne/análise , Mutagênicos/efeitos adversos , Aminas/efeitos adversos , Aminas/análise , Aminas/metabolismo , Estudos de Casos e Controles , Neoplasias Colorretais/epidemiologia , Exposição Dietética/análise , Feminino , Temperatura Alta , Humanos , Masculino , Pessoa de Meia-Idade , Mutagênicos/análise , Mutagênicos/metabolismo , Fatores de Risco , Tennessee/epidemiologia
9.
Biochemistry ; 59(4): 627-634, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31894969

RESUMO

The V27A mutation confers adamantane resistance on the influenza A matrix 2 (M2) proton channel and is becoming more prevalent in circulating populations of influenza A virus. We have used X-ray crystallography to determine structures of a spiro-adamantyl amine inhibitor bound to M2(22-46) V27A and also to M2(21-61) V27A in the Inwardclosed conformation. The spiro-adamantyl amine binding site is nearly identical for the two crystal structures. Compared to the M2 "wild type" (WT) with valine at position 27, we observe that the channel pore is wider at its N-terminus as a result of the V27A mutation and that this removes V27 side chain hydrophobic interactions that are important for binding of amantadine and rimantadine. The spiro-adamantyl amine inhibitor blocks proton conductance in the WT and V27A mutant channels by shifting its binding site in the pore depending on which residue is present at position 27. Additionally, in the structure of the M2(21-61) V27A construct, the C-terminus of the channel is tightly packed relative to that of the M2(22-46) construct. We observe that residues Asp44, Arg45, and Phe48 face the center of the channel pore and would be well-positioned to interact with protons exiting the M2 channel after passing through the His37 gate. A 300 ns molecular dynamics simulation of the M2(22-46) V27A-spiro-adamantyl amine complex predicts with accuracy the position of the ligands and waters inside the pore in the X-ray crystal structure of the M2(22-46) V27A complex.


Assuntos
Adamantano/química , Proteínas da Matriz Viral/química , Proteínas da Matriz Viral/ultraestrutura , Adamantano/análogos & derivados , Adamantano/farmacologia , Aminas/metabolismo , Antivirais/farmacologia , Sítios de Ligação/genética , Cristalografia por Raios X/métodos , Farmacorresistência Bacteriana/genética , Farmacorresistência Viral/efeitos dos fármacos , Humanos , Vírus da Influenza A/genética , Influenza Humana/tratamento farmacológico , Influenza Humana/metabolismo , Ligantes , Simulação de Dinâmica Molecular , Mutação/genética , Radiografia/métodos , Proteínas da Matriz Viral/genética
10.
Chemosphere ; 246: 125753, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31901528

RESUMO

Granules which could efficiently mineralize azo dyes were cultivated through immobilization of aerobic degradation strains in a core composed of anaerobic decolorization cultures. The core was obtained in a up-flow anaerobic sludge blanket (UASB) reactor incubated with anaerobic decolorization bacteria. Aerobic degradation strains were then grown on the surface of the anaerobic core in a sequencing batch reactor (SBR). Three of the granules' surface layers demonstrated the occurrence of immobilization. The granulation process was monitored with 16S rDNA high throughput sequencing. Anaerobic decolorization cultures belonging to the genera of unclassified, Levilinea, and Petrimonas and the aerobic degradation genera of Thauera, unclassified, Thermomonas, and Ottowia were successfully fixed in the granules. The obtained granules were capable of decolorizing azo dyes under anaerobic situation, and the generated aromatic amines were then completely mineralized in aerated environment. Comparative studies on the relationship between removed contaminates and typical components concentrations in low to high strength azo dye wastewater showed that the granules have great potentials in treating wastewater with different complexity. The removal efficiency of COD and TOC was not restricted by loading concentrations.


Assuntos
Compostos Azo/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Aminas/metabolismo , Anaerobiose , Compostos Azo/análise , Bactérias Anaeróbias/metabolismo , Reatores Biológicos , Corantes/metabolismo , Esgotos/microbiologia , Águas Residuárias , Poluentes Químicos da Água/análise
11.
Ecotoxicol Environ Saf ; 191: 110007, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31796253

RESUMO

The biodegradation of dyes remains one of the biggest challenges of textile wastewater. Azo dyes are one of the most commonly employed dye classes, and biological treatment processes tend to generate recalcitrant aromatic amines, which are more toxic than the parent dye molecule. This study aimed to isolate bacterial strains with the capacity to degrade both the azo dye and the resulting aromatic amines towards the development of a simple and reliable treatment approach for dye-laden wastewaters. A mixed bacterial enrichment was first developed in an anaerobic-aerobic lab-scale sequencing batch reactor (SBR) fed with a synthetic textile wastewater containing the model textile azo dye Acid Red 14 (AR14). Eighteen bacterial strains were isolated from the SBR, including members of the Acinetobacter, Pseudomonas and Oerskovia genera, Oerskovia paurometabola presenting the highest decolorization capacity (91% after 24 h in static anaerobic culture). Growth assays supported that this is a facultative bacterium, and decolorization batch tests with 20-100 mg AR14 L-1 in a synthetic textile wastewater supplemented with yeast extract indicated that O. paurometabola has a high color removal capacity for a significant range of AR14 concentrations. In addition, a model typically used to describe biodegradation of xenobiotic compounds was adjusted to the results, to predict AR14 biodegradation time profiles at different initial concentrations. HPLC analysis confirmed that decolorization occurred through azo bond reduction under anaerobic conditions, the azo dye being completely reduced after 24 h of anaerobic incubation for the range of concentrations tested. Interestingly, partial (up to 63%) removal of one of the resulting aromatic amines (4-amino-naphthalene-1-sulfonic acid) was observed when subsequently subjected to aerobic conditions. Overall, this work showed the azo dye biodegradation potential of specific bacterial strains isolated from mixed culture bioreactors, reporting for the first time the decolorization capacity of an Oerskovia sp. with further biodegradation of a recalcitrant sulfonated aromatic amine metabolite.


Assuntos
Actinobacteria/metabolismo , Compostos Azo/metabolismo , Corantes/metabolismo , Águas Residuárias/química , Poluentes Químicos da Água/metabolismo , Aminas/metabolismo , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Cor , Têxteis
12.
Nat Commun ; 10(1): 5470, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784526

RESUMO

Enzymes provide optimal three-dimensional structures for substrate binding and the subsequent accelerated reaction. Such folding-dependent catalytic behaviors, however, are seldom mechanistically explored with reduced structural complexity. Here, we demonstrate that the α-helix, a much simpler structural motif of enzyme, can facilitate its own growth through the self-catalyzed polymerization of N-carboxyanhydride (NCA) in dichloromethane. The reversible binding between the N terminus of α-helical polypeptides and NCAs promotes rate acceleration of the subsequent ring-opening reaction. A two-stage, Michaelis-Menten-type kinetic model is proposed by considering the binding and reaction between the propagating helical chains and the monomers, and is successfully utilized to predict the molecular weights and molecular-weight distributions of the resulting polymers. This work elucidates the mechanism of helix-induced, enzyme-mimetic catalysis, emphasizes the importance of solvent choice in the discovery of new reaction type, and provides a route for rapid production of well-defined synthetic polypeptides by taking advantage of self-accelerated ring-opening polymerizations.


Assuntos
Anidridos/metabolismo , Glutamatos/metabolismo , Polímeros/metabolismo , Conformação Proteica em alfa-Hélice , Aminas/química , Aminas/metabolismo , Anidridos/química , Catálise , Enzimas/química , Enzimas/metabolismo , Glutamatos/química , Cinética , Espectroscopia de Ressonância Magnética , Cloreto de Metileno , Modelos Moleculares , Polimerização , Polímeros/química
14.
Genes (Basel) ; 10(11)2019 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-31717379

RESUMO

Olfactory receptor repertoires show highly dynamic evolution associated with ecological adaptations in different species. The Mariana snailfish (Pseudoliparis swirei) living below a depth of 6000 m in the Mariana Trench evolved degraded vision and occupies a specific feeding habitat in a dark, low-food environment. However, whether such adaptations involve adaptive changes in the chemosensory receptor repertoire is not known. Here, we conducted a comparative analysis of the olfactory receptor (OR) and trace amine-associated receptor (TAAR) gene repertoires in nine teleosts with a focus on the evolutionary divergence between the Mariana snailfish and its shallow-sea relative, Tanaka's snailfish (Liparis tanakae). We found many fewer functional OR genes and a significantly higher fraction of pseudogenes in the Mariana snailfish, but the numbers of functional TAAR genes in the two species were comparable. Phylogenetic analysis showed that the expansion patterns of the gene families were shared by the two species, but that Mariana snailfish underwent massive gene losses in its OR repertoire. Despite an overall decreased size in OR subfamilies and a reduced number of TAAR subfamilies in the Mariana snailfish, expansion of certain subfamilies was observed. Selective pressure analysis indicated greatly relaxed selective strength in ORs but a slightly enhanced selective strength in TAARs of Mariana snailfish. Overall, our study reveals simplified but specific OR and TAAR repertoires in the Mariana snailfish shaped by natural selection with respect to ecological adaptations in the hadal environment. This is the first study on the chemosensation evolution in vertebrates living in the hadal zone, which could provide new insights into evolutionary adaptation to the hadal environment.


Assuntos
Aminas/metabolismo , Peixes/genética , Receptores Odorantes/genética , Aclimatação , Adaptação Biológica/genética , Adaptação Fisiológica , Animais , Evolução Biológica , Ecossistema , Evolução Molecular , Neurônios Receptores Olfatórios/metabolismo , Oceano Pacífico , Perciformes/genética , Filogenia , Pseudogenes , Vertebrados/genética
15.
Enzyme Microb Technol ; 131: 109423, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31615676

RESUMO

Amine-transaminases (ATAs) are enzymes that catalyze the reversible transfer of an amino group between primary amines and carbonyl compounds. They have been widely studied in the last decades for their application in stereoselective synthesis of chiral amines, which are one of the most valuable building blocks in pharmaceuticals manufacturing. Their excellent enantioselectivity, use of low-cost substrates and no need for external cofactors has turned these enzymes into a promising alternative to the chemical synthesis of chiral amines. Nevertheless, its application at industrial scale remains limited mainly because most of the available ATAs are scarcely tolerant to harsh reaction conditions such as high temperatures and presence of organic solvents. In this work, a novel (S)-ATA was discovered in a thermophilic bacterium, Albidovulum sp. SLM16, isolated from a geothermal Antarctic environmental sample, more specifically from a shoreline fumarole in Deception Island. The transaminase-coding gene was identified in the genome of the microorganism, cloned and overexpressed in Escherichia coli for biochemical characterization. The activity of the recombinant ATA was optimal at 65 °C and pH 9.5. Molecular mass estimates suggest a 75 kDa homodimeric structure. The enzyme turned out to be highly thermostable, maintaining 80% of its specific activity after 5 days of incubation at 50 °C. These results indicate that ATA_SLM16 is an excellent candidate for potential applications in biocatalytic synthesis. To the best of our knowledge, this would be the first report of the characterization of a thermostable (S)-ATA discovered by means of in vivo screening of thermophilic microorganisms.


Assuntos
Aminas/metabolismo , Rhodobacteraceae/enzimologia , Transaminases/isolamento & purificação , Transaminases/metabolismo , Regiões Antárticas , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Fontes Termais , Temperatura Alta , Concentração de Íons de Hidrogênio , Peso Molecular , Multimerização Proteica , Rhodobacteraceae/isolamento & purificação , Transaminases/química , Transaminases/genética
16.
Pharmacol Rep ; 71(6): 1140-1146, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31655278

RESUMO

BACKGROUND: 1-Methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ) demonstrates significant neuroprotective activity. It can interact with agonistic conformation of dopamine (DA) receptors. 1MeTIQ inhibits the formation of 3,4-dihydroxyphenylacetic acid as well as production of free radicals and shifts DA catabolism toward COMT-dependent O-methylation. 1MeTIQ inhibits both MAO-A and B enzymes activity and increases neurotransmitters levels in the brain. It shows significant antidepressant-like effect in forced swim test (FST) in rats. This compound might be effective for depression therapy in a clinical setting but its success is determined not only by good efficacy, but also by an acceptable its ADMET profile. The use of combination in silico prediction with in vivoand in vitro studies greatly simplifies the search for new, safer and effectively acting drugs. METHODS: The aim of this study was to investigate the degree of histopathological changes in different rats tissues after acute and chronic administration of 1MeTIQ. Additionally, prediction of its properties in terms of absorption, distribution, metabolism, elimination and toxicity in the human body was performed. RESULTS: The obtained data did not show extensive and significant toxic effects of tested substance in in vivo and in vitro studies in rats, and in silico ADMET prediction. CONCLUSIONS: These results can help to discover a new effective and safe antidepressant substance and have important significance in the treatment of depression in clinic. Additionally, the use in the treatment of depression substance with neuroprotective, antioxidant and antidepressant-like effects in the CNS and existing endogenously might be also beneficial in controlling the adverse CNS inflammatory processes accompanying depression.


Assuntos
Aminas/metabolismo , Antidepressivos/efeitos adversos , Antidepressivos/farmacologia , Tetra-Hidroisoquinolinas/efeitos adversos , Tetra-Hidroisoquinolinas/farmacologia , Ácido 3,4-Di-Hidroxifenilacético/efeitos adversos , Ácido 3,4-Di-Hidroxifenilacético/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Depressão/tratamento farmacológico , Depressão/metabolismo , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/metabolismo , Dopamina/metabolismo , Masculino , Atividade Motora/efeitos dos fármacos , Fármacos Neuroprotetores/efeitos adversos , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Wistar , Natação/fisiologia
17.
Org Biomol Chem ; 17(40): 8982-8986, 2019 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-31584061

RESUMO

A facile microwave assisted three-component protocol allows the synthesis of chiral aryl-1,2-mercaptoamines in water in a few minutes with high yields, bypassing the use of toxic aziridine intermediates. The chiral 1,2-mercaptoamines were then deracemized through enzymatic resolution of the racemates using monoamine oxidase (MAO-N) biocatalysts.


Assuntos
Aminas/metabolismo , Monoaminoxidase/metabolismo , Água/metabolismo , Aminas/síntese química , Aminas/química , Biocatálise , Micro-Ondas , Modelos Moleculares , Estrutura Molecular , Monoaminoxidase/química , Estereoisomerismo , Água/química
18.
PLoS One ; 14(10): e0223878, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31622392

RESUMO

In the 60 years since Skoog and Miller first reported the chemical redirection of plant growth the underlying biochemical mechanisms are still poorly understood, with one challenge being the capacity for applied growth regulators to act indirectly or be metabolized to active phytohormones. We hypothesized that tryptophan is metabolized to auxin, melatonin or serotonin inducing organogenesis in St. John's wort (Hypericum perforatum L.). Root explants from two germplasm lines of St. John's wort with altered melatonin metabolism and wildtype were incubated with auxin or tryptophan for 24, 48 or 72 h to induce regeneration. In wildtype, tryptophan had little effect on the indoleamine pathway, and was found to promote primary growth, suggesting excess tryptophan moved quickly through various secondary metabolite pathways and protein synthesis. In lines 4 and 112 tryptophan was associated with modified morphogenesis, indoleamine and auxin levels. Incubation with tryptophan increased shoot organogenesis while incubation with auxin led to root regeneration. The established paradigm of thought views tryptophan primarily as a precursor for auxin and indoleamines, among other metabolites, and mediation of auxin action by the indoleamines as a one-way interaction. We propose that these processes run in both directions with auxin modifying indoleamine biosynthesis and the melatonin:serotonin balance contributing to its effects on plant morphogenesis, and that tryptophan also functions as an inductive signal to mediate diverse phytochemical and morphogenetic pathways.


Assuntos
Aminas/metabolismo , Hypericum/efeitos dos fármacos , Ácidos Indolacéticos/farmacologia , Triptofano/metabolismo , Hypericum/crescimento & desenvolvimento , Hypericum/metabolismo , Ácidos Indolacéticos/metabolismo , Indóis/química , Modelos Lineares , Melatonina/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Serotonina/metabolismo , Triptofano/farmacologia
19.
Insect Biochem Mol Biol ; 115: 103245, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31604119

RESUMO

The amine-binding properties of sand fly salivary yellow-related proteins (YRPs) were described only in Lutzomyia longipalpis sand flies. Here, we experimentally confirmed the kratagonist function of YRPs in the genus Phlebotomus. We utilized microscale thermophoresis technique to determine the amine-binding properties of YRPs in saliva of Phlebotomus perniciosus and P. orientalis, the Old-World vectors of visceral leishmaniases causative agents. Expressed and purified YRPs from three different sand fly species were tested for their interactions with various biogenic amines, including serotonin, histamine and catecholamines. Using the L. longipalpis YRP LJM11 as a control, we have demonstrated the comparability of the microscale thermophoresis method with conventional isothermal titration calorimetry described previously. By homology in silico modeling, we predicted the surface charge and both amino acids and hydrogen bonds of the amine-binding motifs to influence the binding affinities between closely related YRPs. All YRPs tested bound at least two biogenic amines, while the affinities differ both among and within species. Low affinity was observed for histamine. The salivary recombinant proteins rSP03B (P. perniciosus) and rPorASP4 (P. orientalis) showed high-affinity binding of serotonin, suggesting their capability to facilitate inhibition of the blood vessel contraction and platelet aggregation.


Assuntos
Aminas/metabolismo , Proteínas de Insetos/metabolismo , Phlebotomus/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Animais , Conformação Proteica , Glândulas Salivares/metabolismo , Eletricidade Estática
20.
J Chromatogr A ; 1608: 460413, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31395359

RESUMO

Recent advances in metabolomics have enabled larger proportions of the human metabolome to be analyzed quantitatively. However, this usually requires the use of several chromatographic methods coupled to mass spectrometry to cover the wide range of polarity, acidity/basicity and concentration of metabolites. Chemical derivatization allows in principle a wide coverage in a single method, as it affects both the separation and the detection of metabolites: it increases retention, stabilizes the analytes and improves the sensitivity of the analytes. The majority of quantitative derivatization techniques for LC-MS in metabolomics react with amines, phenols and thiols; however, there are unfortunately very few methods that can target carboxylic acids at the same time, which contribute to a large proportion of the human metabolome. Here, we describe a derivatization technique which simultaneously labels carboxylic acids, thiols and amines using the reagent dimethylaminophenacyl bromide (DmPABr). We further improve the quantitation by employing isotope-coded derivatization (ICD), which uses internal standards derivatized with an isotopically-labelled reagent (DmPABr-D6). We demonstrate the ability to measure and quantify 64 central carbon and energy-related metabolites including amino acids, N-acetylated amino acids, metabolites from the TCA cycle and pyruvate metabolism, acylcarnitines and medium-/long-chain fatty acids. To demonstrate the applicability of the analytical approach, we analyzed urine and SUIT-2 cells utilizing a 15-minute single UPLC-MS/MS method in positive ionization mode. SUIT-2 cells exposed to rotenone showed definitive changes in 28 out of the 64 metabolites, including metabolites from all 7 classes mentioned. By realizing the full potential of DmPABr to derivatize and quantify amines and thiols in addition to carboxylic acids, we extended the coverage of the metabolome, producing a strong platform that can be further applied to a variety of biological studies.


Assuntos
Carbono/química , Carbono/metabolismo , Aminas/química , Aminas/metabolismo , Aminoácidos/análise , Brometos/química , Carbono/urina , Ácidos Carboxílicos/análise , Ácidos Carboxílicos/metabolismo , Linhagem Celular , Cromatografia Líquida/métodos , Humanos , Metaboloma , Metabolômica/métodos , Espectrometria de Massas em Tandem/métodos
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