Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 758
Filtrar
1.
Chem Asian J ; : e202400945, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39233481

RESUMO

A convenient and practical multicomponent strategy for the sulfenoamination of alkenes was realized, which using free-thiols as the sulfur-reagent, NIS both as radical initiator and an N-nucleophile. This protocol excellent in terms of transition-metal-free, good functional group tolerance, easily available substrates and facile scale-up. And provided a direct- and general way to synthesize various ß-succinimide sulfides with high regioselectivity.

2.
Int J Food Microbiol ; 425: 110858, 2024 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-39163814

RESUMO

The aromatic profile of wine determines its overall final quality, and among the volatile molecules that define it, varietal thiols are responsible for shaping the distinctive character of certain wine varieties. In grape must, these thiols are conjugated to amino acids or small peptides in a non-volatile form. During wine fermentation, yeasts play a principal role in expressing these aromatic compounds as they internalise and cleavage these precursors, releasing the corresponding free and aroma-impacting fraction. Here, we investigate the impact of three wine yeasts (Saccharomyces cerevisiae, Torulaspora delbrueckii and Lachancea thermotolerans) on thiol releasing in synthetic grape must fermentations supplemented with different cysteinylated (Cys-4MSP and Cys-3SH) and glutathionylated (GSH-4MSP and GSH-3SH) precursors. We demonstrate higher consumption levels of cysteinylated precursors, and consequently, higher amounts of thiols are released from them compared to glutathionylated ones. We also report a significant impact of yeast inoculated on the final thiols released. Meanwhile T. delkbrueckii exhibits a great 3SHA releasing capacity, L. thermotolerans stands out because of its high 3SH release. We also highlight the synergic effect of the co-inoculation strategy, especially relevant in the case of S. cerevisiae and L. thermotolerans mixed fermentation, that has an outstanding release of 4MSP thiol. Although our results stem from a specific experimental approach that differs from real winemaking situations, these findings reveal the potential of unravelling the specific role of different yeast species, thiol precursors and their interaction, to improve wine production processes in the context of wine aroma enhancement.


Assuntos
Fermentação , Saccharomyces cerevisiae , Compostos de Sulfidrila , Torulaspora , Vinho , Vinho/microbiologia , Vinho/análise , Compostos de Sulfidrila/metabolismo , Saccharomyces cerevisiae/metabolismo , Torulaspora/metabolismo , Saccharomycetales/metabolismo , Saccharomycetales/crescimento & desenvolvimento , Vitis/microbiologia , Odorantes/análise
3.
Adv Cancer Res ; 162: 99-124, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39069371

RESUMO

It has been well established that in addition to oxygen's vital in cellular respiration, a disruption of oxygen balance can lead to increased stress and oxidative injury. Similarly, reduced oxygen during tumor proliferation and invasion generates a hypoxic tumor microenvironment, resulting in dysfunction of immune cells and providing a conducive milieu for tumors to adapt and grow. Strategies to improve the persistence tumor reactive T cells in the highly oxidative tumor environment are being pursued for enhancing immunotherapy outcomes. To this end, we have focused on various strategies that can help increase or maintain the antioxidant capacity of T cells, thus reducing their susceptibility to oxidative stress/damage. Herein we lay out an overview on the role of oxygen in T cell signaling and how pathways regulating oxidative stress or antioxidant signaling can be targeted to enhance immunotherapeutic approaches for cancer treatment.


Assuntos
Antioxidantes , Neoplasias , Linfócitos T , Microambiente Tumoral , Humanos , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/terapia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Microambiente Tumoral/imunologia , Estresse Oxidativo , Imunoterapia/métodos
4.
Chem Asian J ; : e202400698, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39039023

RESUMO

A very simple and atom-economical method for the synthesis of vicinal trifluoromethyl thioethers via DBN-catalyzed hydrothiolation of α-trifluoromethyl styrenes with thiols was reported. The reaction proceeded smoothly under mild reaction conditions and provided the ß-CF3-thioethers in moderate to good yields in an anti-Markovnikov manner.

5.
ChemMedChem ; : e202400345, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-39031732

RESUMO

Novel chalcogen-containing amides and esters bearing the benzenesulfonamide moiety have been synthesised upon nucleophilic conjugate addition of thiols and selenols to suitable electron-deficient alkenes. The activity of the synthesised compounds as Carbonic Anhydrases inhibitors has been investigated in vitro and the inhibition mechanism has been elucidated by X-rays studies.

6.
Environ Sci Technol ; 58(32): 14410-14420, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39082216

RESUMO

Complexes with low-molecular-weight thiols are crucial species of methylmercury (MeHg) excreted by anaerobic Hg-methylating microbes, notably, MeHg-cysteine (MeHg-Cys). As MeHg-Cys diffuses into surface water, it would undergo a ligand exchange process with dissolved organic matter (DOM) under nonsulfidic conditions, inevitably altering MeHg speciation and bioavailability to phytoplankton. In this study, we investigated the competitive binding kinetics between MeHg-Cys and Suwannee River natural organic matter, and their influence on the adsorption and uptake of MeHg by the cyanobacterium, Synechocystis sp. PCC6803. Liquid chromatography-inductively coupled plasma mass spectrometry was employed to monitor the kinetics processes involving competition of DOM with Cys for MeHg binding, which revealed that competitive binding kinetics were dictated by the abundance of thiol moieties in DOM. Thiol concentrations of 0.97 and 49.34 µmol of thiol (g C)-1 resulted in competitive binding rate constant (k values) of 0.30 and 3.47 h-1, respectively. Furthermore, the time-dependent competitive binding of DOM toward MeHg-Cys significantly inhibited MeHg adsorption and uptake by cyanobacteria, an effect that was amplified by an increased thiol abundance in DOM. These findings offer valuable insights into the kinetic characteristics of MeHg's fate and transport, as well as their impact on bioconcentration in aquatic organisms within natural aquatic ecosystems.


Assuntos
Compostos de Metilmercúrio , Compostos de Sulfidrila , Compostos de Metilmercúrio/metabolismo , Compostos de Metilmercúrio/química , Adsorção , Cinética , Compostos de Sulfidrila/metabolismo , Compostos de Sulfidrila/química , Cisteína/metabolismo , Cisteína/química , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/química
7.
Free Radic Biol Med ; 223: 131-143, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39084576

RESUMO

Water buffalo horn (WBH), a traditional Chinese medicine, is known for its antipyretic, anti-inflammatory and antioxidant properties. This study aims to investigate the therapeutic potential of WBH keratin (WBHK) and its derived thiol-rich peptide fractions (SHPF) for oxidative stress and inflammation. WBHK and SHPF were prepared and tested using various models including LPS-induced fever in rabbits, H2O2-induced oxidative damage in bEnd.3 cells, TNF-α-induced inflammation in bEnd.3 cells and LPS-induced inflammation in RAW 264.7 cells. Expression of key markers, such as Nrf2, Hmox-1 and NF-κB, were analyzed using qRT-PCR, ELISA and Western blotting. Label-free quantitative proteomic analysis was used to identify key differential proteins associated with the efficacy of SHPF. Our results demonstrated that treatment with WBHK significantly reduced body temperature after 0.5 h of administration in the fever rabbit model. SHPF could alleviate cellular inflammatory injury and oxidative damage by activating the key transcription factor Nrf2 and increasing the expression level of Hmox-1. SHPF could inhibit the NF-κB pathway by reducing IκB phosphorylation. It was also found that SHPF could reduce pro-inflammatory cytokine (IL-6, COX-2 and PGE2) and inhibit the expression of VCAM-1, ICAM-1, IL-6 and MCP-1. Proteomics analysis showed that SHPF could inhibit HMGB1 expression and release. The results indicated that SHPF could significantly reduce inflammation and oxidative stress by regulating the Nrf2/Hmox-1 and NF-κB pathways. These findings suggest the potential therapeutic applications of WBH components in the treatment of oxidative stress and inflammation-related diseases.


Assuntos
Heme Oxigenase-1 , Inflamação , Queratinas , Fator 2 Relacionado a NF-E2 , NF-kappa B , Estresse Oxidativo , Peptídeos , Transdução de Sinais , Animais , Estresse Oxidativo/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Fator 2 Relacionado a NF-E2/genética , Coelhos , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Camundongos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Inflamação/induzido quimicamente , Heme Oxigenase-1/metabolismo , Heme Oxigenase-1/genética , Queratinas/metabolismo , Peptídeos/farmacologia , Búfalos , Células RAW 264.7 , Compostos de Sulfidrila/metabolismo , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Antioxidantes/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Cornos/química , Lipopolissacarídeos , Febre/tratamento farmacológico , Febre/induzido quimicamente , Febre/metabolismo , Peróxido de Hidrogênio/metabolismo , Masculino , Medicina Tradicional Chinesa
8.
Int J Mol Sci ; 25(14)2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39063017

RESUMO

Non-enzyme-catalyzed thiol addition onto the α,ß-unsaturated carbonyl system is associated with several biological effects. Kinetics and diastereoselectivity of non-enzyme catalyzed nucleophilic addition of reduced glutathione (GSH) and N-acetylcysteine (NAC) to the six-membered cyclic chalcone analogs 2a and 2b were investigated at different pH values (pH 3.2, 7.4 and 8.0). The selected compounds displayed in vitro cancer cell cytotoxicity (IC50) of different orders of magnitude. The chalcones intrinsically reacted with both thiols under all incubation conditions. The initial rates and compositions of the final mixtures depended both on the substitution and the pH. The stereochemical outcome of the reactions was evaluated using high-pressure liquid chromatography with UV detection (HPLC-UV). The structures of the formed thiol-conjugates and the retro-Michael products (Z)-2a and (Z)-2b were confirmed by high-pressure liquid chromatography-mass spectrometry (HPLC-MS). Frontier molecular orbitals and the Fukui function calculations were carried out to investigate their effects on the six-membered cyclic analogs. Data were compared with those obtained with the open-chain (1) and the seven-membered (3) analogs. The observed reactivities do not directly relate to the difference in in vitro cancer cell cytotoxicity of the compounds.


Assuntos
Chalconas , Compostos de Sulfidrila , Humanos , Chalconas/química , Chalconas/farmacologia , Compostos de Sulfidrila/química , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/química , Cromatografia Líquida de Alta Pressão , Glutationa/metabolismo , Glutationa/química , Cinética , Compostos de Benzilideno/química
9.
mLife ; 3(2): 231-239, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38948149

RESUMO

Members of the multiple antibiotic resistance regulator (MarR) protein family are ubiquitous in bacteria and play critical roles in regulating cellular metabolism and antibiotic resistance. MarR family proteins function as repressors, and their interactions with modulators induce the expression of controlled genes. The previously characterized modulators are insufficient to explain the activities of certain MarR family proteins. However, recently, several MarR family proteins have been reported to sense sulfane sulfur, including zero-valent sulfur, persulfide (R-SSH), and polysulfide (R-SnH, n ≥ 2). Sulfane sulfur is a common cellular component in bacteria whose levels vary during bacterial growth. The changing levels of sulfane sulfur affect the expression of many MarR-controlled genes. Sulfane sulfur reacts with the cysteine thiols of MarR family proteins, causing the formation of protein thiol persulfide, disulfide bonds, and other modifications. Several MarR family proteins that respond to reactive oxygen species (ROS) also sense sulfane sulfur, as both sulfane sulfur and ROS induce the formation of disulfide bonds. This review focused on MarR family proteins that sense sulfane sulfur. However, the sensing mechanisms reviewed here may also apply to other proteins that detect sulfane sulfur, which is emerging as a modulator of gene regulation.

10.
Metab Brain Dis ; 39(5): 929-940, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38848024

RESUMO

The nature of brain redox metabolism in health, aging, and disease remains to be fully established. Reversible oxidations, to disulfide bonds, of closely spaced (vicinal) protein thiols underlie the catalytic maintenance of redox homeostasis by redoxin enzymes, including thioredoxin peroxidases (peroxiredoxins), and have been implicated in redox buffering and regulation. We propose that non-peroxidase proteins containing vicinal thiols that are responsive to physiological redox perturbations may serve as intrinsic probes of brain redox metabolism. Using redox phenylarsine oxide (PAO)-affinity chromatography, we report that PAO-binding vicinal thiols on creatine kinase B and alpha-enolase from healthy rat brains were preferentially oxidized compared to other selected proteins, including neuron-specific (gamma) enolase, under conditions designed to trap in vivo protein thiol redox states. Moreover, measures of the extents of oxidations of vicinal thiols on total protein, and on creatine kinase B and alpha-enolase, showed that vicinal thiol-linked redox states were stable over the lifespan of rats and revealed a transient reductive shift in these redox couples following decapitation-induced global ischemia. Finally, formation of disulfide-linked complexes between peroxiredoxin-2 and brain proteins was demonstrated on redox blots, supporting a link between protein vicinal thiol redox states and the peroxidase activities of peroxiredoxins. The implications of these findings with respect to underappreciated aspects of brain redox metabolism in health, aging, and ischemia are discussed.


Assuntos
Envelhecimento , Isquemia Encefálica , Encéfalo , Oxirredução , Compostos de Sulfidrila , Animais , Ratos , Envelhecimento/metabolismo , Compostos de Sulfidrila/metabolismo , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Masculino , Fosfopiruvato Hidratase/metabolismo , Arsenicais/metabolismo , Creatina Quinase Forma BB/metabolismo , Ratos Sprague-Dawley
11.
Int J Mol Sci ; 25(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38892167

RESUMO

New ß-amino-substituted porphyrin derivatives bearing carboxy groups were synthesized and their performance as sensitizers in dye-sensitized solar cells (DSSC) was evaluated. The new compounds were obtained in good yields (63-74%) through nucleophilic aromatic substitution reactions with 3-sulfanyl- and 4-sulfanylbenzoic acids. Although the electrochemical studies indicated suitable HOMO and LUMO energy levels for use in DSSC, the devices fabricated with these compounds revealed a low power conversion efficiency (PCE) that is primarily due to the low open-circuit voltage (Voc) and short-circuit current density (Jsc) values.


Assuntos
Porfirinas , Energia Solar , Porfirinas/química , Porfirinas/síntese química
12.
ACS Catal ; 14(9): 6973-6980, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38737399

RESUMO

Development of photocatalytic systems that facilitate mechanistically divergent steps in complex catalytic manifolds by distinct activation modes can enable previously inaccessible synthetic transformations. However, multimodal photocatalytic systems remain understudied, impeding their implementation in catalytic methodology. We report herein a photocatalytic access to thiols that directly merges the structural diversity of carboxylic acids with the ready availability of elemental sulfur without substrate preactivation. The photocatalytic transformation provides a direct radical-mediated segue to one of the most biologically important and synthetically versatile organosulfur functionalities, whose synthetic accessibility remains largely dominated by two-electron-mediated processes based on toxic and uneconomical reagents and precursors. The two-phase radical process is facilitated by a multimodal catalytic reactivity of acridine photocatalysis that enables both the singlet excited state PCET-mediated decarboxylative carbon-sulfur bond formation and the previously unknown radical reductive disulfur bond cleavage by a photoinduced HAT process in the silane-triplet acridine system. The study points to a significant potential of multimodal photocatalytic systems in providing unexplored directions to previously inaccessible transformations.

13.
Water Sci Technol ; 89(9): 2523-2537, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38747965

RESUMO

Miscanthus sacchariflorus is previously demonstrated to be a potential candidate for remediation of cadmium (Cd) pollution. To explore its resistance strategy to Cd, a hydroponic experiment was conducted to determine the variations of photosynthetic activity in leaves and physiological response in roots of this plant. Results showed that the root of M. sacchariflorus was the primary location for Cd accumulation. The bioconcentration factor in the roots and rhizomes was >1, and the translocation factor from underground to aboveground was <1. Throughout the experimental period, treatment with 0.06 mM Cd2+ did not significantly alter the contents of chlorophyll a, chlorophyll b, or carotenoid. By contrast, treatment with 0.15 and 0.30 mM Cd2+ decreased the contents of chlorophyll a, chlorophyll b, and carotenoid; caused the deformation of the chlorophyll fluorescence transient curve; reduced the photochemical efficiency of photosystem II; and increased the contents of non-protein thiols, total flavone, and total phenol. These results indicate that M. sacchariflorus has good adaptability to 0.06 mM Cd2+. Moreover, the accumulation of the non-protein thiols, total flavone, and total phenol in roots may promote the chelation of Cd2+, thus alleviating Cd toxicity. This study provides theoretical support for using M. sacchariflorus to remediate Cd-polluted wetlands.


Assuntos
Cádmio , Fotossíntese , Poaceae , Compostos de Sulfidrila , Cádmio/toxicidade , Cádmio/metabolismo , Fotossíntese/efeitos dos fármacos , Poaceae/metabolismo , Poaceae/efeitos dos fármacos , Compostos de Sulfidrila/metabolismo , Clorofila/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Biodegradação Ambiental
14.
Chembiochem ; 25(17): e202400148, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-38629812

RESUMO

Native chemical ligation is a key reaction in the toolbox of chemical methods for the synthesis of native and modified proteins. The catalysis of ligation is commonly performed by using small aryl-thiol molecules added at high concentrations. In this work, we incorporated thiotyrosine, a non-canonical amino acid containing an aryl-thiol moiety, into a designed cyclic protein « sans queue ni tête ¼. Importantly, the protein environment reduced the pKa of the thiol group to 5.8-5.9, which is significantly lower than the previously reported value for thiotyrosine in a short peptide (pKa 6.4). Furthermore, we demonstrated the catalytic activity of this protein both as hydrolase and in native chemical ligation of peptides. These results will be useful for the development of efficient protein catalysts (enzymes) for protein synthesis and modification.


Assuntos
Domínio Catalítico , Tirosina , Tirosina/química , Tirosina/análogos & derivados , Catálise , Biocatálise , Compostos de Sulfidrila/química , Peptídeos Cíclicos/química , Peptídeos Cíclicos/síntese química , Estrutura Molecular , Proteínas/química , Proteínas/síntese química
15.
Se Pu ; 42(4): 352-359, 2024 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-38566424

RESUMO

Oxidative stress, which is characterized by an imbalance between antioxidants and free radicals, plays a pivotal role in the pathogenesis of coronary heart disease, a common and serious cardiovascular condition, and contributes significantly to its development and progression. Serum free thiols are crucial components of the body's antioxidant defense system. The accurate determination of serum free thiol levels provides a reference basis for understanding the body's status and monitoring the risk factors associated with the occurrence and progression of coronary heart disease. In this study, a high performance liquid chromatographic (HPLC) method based on the derivatization reaction of 2,2'-dithiodipyridine was developed to simultaneously obtain the concentrations of total free thiols (Total-SH), low-molecular-mass free thiols (LMM-SH), and protein-free thiols (P-SH) in human serum. An Agilent Eclipse XDB-C18 column (150 mm×4.6 mm, 5 µm) was used for the analysis, and gradient elution was performed at a flow rate of 1 mL/min. A 0.1% formic acid aqueous solution was used as mobile phase A, and a 0.1% formic acid acetonitrile solution was used as mobile phase B. The gradient elution program was as follows: 0-0.1 min, 12%B-30%B; 0.1-2 min, 30%B; 2-2.1 min, 30%B-100%B; 2.1-6 min, 100%B; 6-6.1 min, 100%B-12%B; 6.1-7 min, 12%B. Well-separated peaks appeared after a run time of 5 min. The peak of 2-thiopyridone represented the Total-SH content of the samples, and the peak of the pyridyldithio derivative represented the LMM-SH content. The difference between these two peaks indicated the P-SH content. The derivatization reaction conditions were optimized, and the method was validated. The method demonstrated good linearity, with a correlation coefficient ≥0.9994, over the concentration range of 31.25-1000 µmol/L. The limits of detection for Total-SH and LMM-SH were 2.61 and 0.50 µmol/L, and the limits of quantification for Total-SH and LMM-SH were 8.71 and 1.67 µmol/L, respectively. The recoveries of Total-SH and LMM-SH were in the range of 91.1%-106.0%. The intra- and inter-day precisions ranged from 0.4% to 9.1%. The developed method was used to analyze serum samples from 714 volunteers. The Total-SH concentrations ranged from 376.60 to 781.12 µmol/L, with an average concentration of 555.62 µmol/L. The LMM-SH concentrations varied from 36.37 to 231.65 µmol/L,with an average of 82.34 µmol/L. The P-SH concentrations ranged from 288.36 to 687.74 µmol/L, with an average of 473.27 µmol/L. Spearman's correlation test showed that serum thiol levels were correlated with the severity of coronary artery disease and common clinical biochemical indicators. The proposed study provides a simple and reliable HPLC method for detecting serum free thiols and exploring their relationship with coronary heart disease, offering a new reference for the study of markers related to the risk of coronary heart disease.


Assuntos
2,2'-Dipiridil/análogos & derivados , Doença das Coronárias , Dissulfetos , Formiatos , Compostos de Sulfidrila , Humanos , Cromatografia Líquida de Alta Pressão , Antioxidantes
16.
Biol Trace Elem Res ; 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38676879

RESUMO

Selenium compounds exert their antioxidant activity mostly when the selenium atom is incorporated into selenoproteins. In our work, we tested the possibility that selenite itself interacts with thiols to form active species that have reducing properties. Therefore, we studied the reduction of 2-(4-carboxyphenyl)-4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazol-1-yloxy-3-oxide radical (•cPTIO), damage of plasmid DNA (pDNA), modulation of rat hemodynamic parameters and tension of isolated arteries induced by products of interaction of selenite with thiols. We found that the products of selenite interaction with thiols had significant reducing properties that could be attributed mainly to the selenide and that selenite had catalytic properties in the access of thiols. The potency of thiols to reduce •cPTIO in the interaction with selenite was cysteine > homocysteine > glutathione reduced > N-acetylcysteine. Thiol/selenite products cleaved pDNA, with superoxide dismutase enhancing these effects suggesting a positive involvement of superoxide anion in the process. The observed •cPTIO reduction and pDNA cleavage were significantly lower when selenomethionine was used instead of selenite. The products of glutathione/selenite interaction affected several hemodynamic parameters including rat blood pressure decrease. Notably, the products relaxed isolated mesenteric artery, which may explain the observed decrease in rat blood pressure. In conclusion, we found that the thiol/selenite interaction products exhibited significant reducing properties which can be used in further studies of the treatment of pathological conditions caused by oxidative stress. The results of decreased rat blood pressure and the tension of mesenteric artery may be perspective in studies focused on cardiovascular disease and their prevention.

17.
Biochemistry (Mosc) ; 89(Suppl 1): S180-S204, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38621750

RESUMO

In many proteins, supplementary metal-binding centers appear under stress conditions. They are known as aberrant or atypical sites. Physico-chemical properties of proteins are significantly changed after such metal binding, and very stable protein aggregates are formed, in which metals act as "cross-linking" agents. Supplementary metal-binding centers in proteins often arise as a result of posttranslational modifications caused by reactive oxygen and nitrogen species and reactive carbonyl compounds. New chemical groups formed as a result of these modifications can act as ligands for binding metal ions. Special attention is paid to the role of cysteine SH-groups in the formation of supplementary metal-binding centers, since these groups are the main target for the action of reactive species. Supplementary metal binding centers may also appear due to unmasking of amino acid residues when protein conformation changing. Appearance of such centers is usually considered as a pathological process. Such unilateral approach does not allow to obtain an integral view of the phenomenon, ignoring cases when formation of metal complexes with altered proteins is a way to adjust protein properties, activity, and stability under the changed redox conditions. The role of metals in protein aggregation is being studied actively, since it leads to formation of non-membranous organelles, liquid condensates, and solid conglomerates. Some proteins found in such aggregates are typical for various diseases, such as Alzheimer's and Huntington's diseases, amyotrophic lateral sclerosis, and some types of cancer.


Assuntos
Metais , Estresse Oxidativo , Metais/química , Metais/metabolismo , Oxirredução , Processamento de Proteína Pós-Traducional
18.
Antioxidants (Basel) ; 13(3)2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38539887

RESUMO

The imbalance in oxidative stress in acute stroke has been extensively studied; on the contrary, its investigation in the subacute phase is limited. The aim of this study was to analyse the variation in the systemic oxidative status in subacute post-stroke patients before (T0) and after a six-week rehabilitation treatment (T1) and to investigate the relationship between systemic oxidative status and rehabilitation outcomes. We enrolled 109 subjects in two different centres, and we analysed their serum hydroperoxide levels (d-ROMs), biological antioxidant power (BAP), thiol antioxidant components (-SHp), and relative antioxidant capacity (OSI and SH-OSI indices). Activity of Daily Living (ADL), hand grip strength, and walking endurance were evaluated using the modified Barthel Index, the Hand Grip test, and the 6-min walk test, respectively. At T0, most of the patients showed very high levels of d-ROMs and suboptimal levels of the BAP, OSI, and SH-OSI indices. Comparing the T1 and T0 data, we observed an improvement in the rehabilitation outcomes and a significant decrease in d-ROMs (549 ± 126 vs. 523 ± 148, p = 0.023), as well as an improvement in the OSI and SH-OSI indices (4.3 ± 1.3 vs. 4.7 ± 1.5, p = 0.001; 11.0 ± 0.4 vs. 1.2 ± 0.4, p < 0.001). In addition, significant correlations were seen between the oxidative stress parameters and the rehabilitation outcomes. These results suggest monitoring the systemic oxidative stress status in post-stroke patients in order to plan a tailored intervention, considering its relationship with functional recovery.

19.
Redox Biol ; 71: 103094, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38479221

RESUMO

Low-molecular-weight (LMW) thiols are produced in all living cells in different forms and concentrations. Glutathione (GSH), coenzyme A (CoA), bacillithiol (BSH), mycothiol (MSH), ergothioneine (ET) and trypanothione T(SH)2 are the main LMW thiols in eukaryotes and prokaryotes. LMW thiols serve as electron donors for thiol-dependent enzymes in redox-mediated metabolic and signaling processes, protect cellular macromolecules from oxidative and xenobiotic stress, and participate in the reduction of oxidative modifications. The level and function of LMW thiols, their oxidized disulfides and mixed disulfide conjugates in cells and tissues is tightly controlled by dedicated oxidoreductases, such as peroxiredoxins, glutaredoxins, disulfide reductases and LMW thiol transferases. This review provides the first summary of the current knowledge of structural and functional diversity of transferases for LMW thiols, including GSH, BSH, MSH and T(SH)2. Their role in maintaining redox homeostasis in single-cell and multicellular organisms is discussed, focusing in particular on the conjugation of specific thiols to exogenous and endogenous electrophiles, or oxidized protein substrates. Advances in the development of new research tools, analytical methodologies, and genetic models for the analysis of known LMW thiol transferases will expand our knowledge and understanding of their function in cell growth and survival under oxidative stress, nutrient deprivation, and during the detoxification of xenobiotics and harmful metabolites. The antioxidant function of CoA has been recently discovered and the breakthrough in defining the identity and functional characteristics of CoA S-transferase(s) is soon expected.


Assuntos
Antioxidantes , Compostos de Sulfidrila , Compostos de Sulfidrila/metabolismo , Antioxidantes/metabolismo , Transferases/metabolismo , Oxirredução , Glutationa/metabolismo , Oxirredutases/metabolismo , Dissulfetos/química
20.
Anal Sci ; 40(6): 997-1021, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38523231

RESUMO

It is well-known fact that elevated lead ions (Pb2+), the third most toxic among heavy metal ions in aqueous systems, pose a threat to human health and aquatic ecosystems when they exceed permissible limits. Pb2+ is commonly found in industrial waste and fertilizers, contaminating water sources and subsequently entering the human body, causing various adverse health conditions. Unlike being expelled, Pb2+ accumulates within the body, posing potential health risks. The harmful impact of presence of Pb2+ in water have prompted researchers to diligently work toward maintaining water quality. Recognizing the importance of Pb2+, this review article makes a sincere and effective effort to address the issues associated with Pb2+. This overview article gives insights into various sensing approaches to detect Pb2+ in water using different sensing materials, including 2-dimensional materials, thiols, quantum dots, and polymers. Herein, different sensing approaches such as electrochemical, optical, field effect transistor-based, micro-electromechanical system-based, and chemi resistive are thoroughly explained. Field effect transistor-based and chemiresistive work on similar principles and are compared on the basis of their fabrication processes and sensing capabilities. In conclusion, future directions for chemiresistive sensors in Pb2+ detection are proposed, emphasizing their simplicity, portability, straightforward functionality, and ease of fabrication. Notably, it sheds light on various thiol and ligand compounds and coupling strategies utilized in Pb2+ detection. This comprehensive study is expected to benefit individuals engaged in Pb2+ detection.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...