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1.
Biochem Biophys Res Commun ; 696: 149483, 2024 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-38219484

RESUMO

Highly cytotoxic maytansine derivatives are widely used in targeted tumor delivery. Structure-activity studies published earlier suggested the C9 carbinol to be a key element necessary to retain the potency. However, in 1984 a patent was published by Takeda in which the synthesis of 9-thioansamitocyn (AP3SH) was described and its activity in xenograft models was shown. In this article we summarize the results of an extended study of the anti-tumor properties of AP3SH. Like other maytansinoids, it induces apoptosis and arrests the cell cycle in the G2/M phase. It is metabolized in liver microsomes predominately by C3A4 isoform and doesn't inhibit any CYP isoforms except CYP3A4 (midazolam, IC50 7.84 µM). No hERG inhibition, CYP induction or mutagenicity in Ames tests were observed. AP3SH demonstrates high antiproliferative activity against 25 tumor cell lines and tumor growth inhibition in U937 xenograft model. Application of AP3SH as a cytotoxic payload in drug delivery system was demonstrated by us earlier.


Assuntos
Antineoplásicos , Maitansina , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/metabolismo , Linhagem Celular Tumoral , Ciclo Celular , Divisão Celular
2.
Environ Sci Technol ; 57(4): 1680-1691, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36642941

RESUMO

Precise and reliable onsite detection of methyl mercaptan (CH3SH) is of great significance for environmental surveillance. Here, we synthesized a novel blue fluorescence nanozyme CeO2@TPE with high peroxidase-like activity by employing aggregation-induced emission (AIE) tetraphenylethene (TPE) to embed into hollow CeO2 nanospheres. In the presence of ethanol oxidase (AOX) and o-phenylenediamine (OPD), we engineered an enzymatic cascade activation ratiometric fluorescence-colorimetric dual-mode system AOX/CeO2@TPE + OPD toward CH3SH. In this design, CH3SH initiated AOX catalytic activity to convert it into H2O2 for activating the peroxidase-like activity of CeO2@TPE, producing •OH for oxidizing the naked-eye colorless OPD into deep yellow 2,3-diaminophenazine (DAP) with an absorption enhancement at ∼425 nm, companied by a new emission peak at ∼550 nm to match with the intrinsic emission at ∼441 nm for observing ratiometric fluorescence response, enabling a ratiometric fluorescence-colorimetric dual-mode analysis. Interestingly, both the ratiometric fluorescence and colorimetric signals could be gathered for being converted into the hue parameter on a smartphone-based sensor, achieving the onsite visual fluorescence-colorimetric dual-mode detection of CH3SH in real environmental media with acceptable results. This study gave a novel insight into designing target-responsive enzymatic cascade activation system-based efficient and reliable dual-mode point-of-care sensors for safeguarding environmental health.


Assuntos
Colorimetria , Smartphone , Colorimetria/métodos , Peróxido de Hidrogênio , Peroxidases , Compostos de Sulfidrila , Limite de Detecção
3.
Environ Sci Technol ; 57(50): 21470-21482, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38050842

RESUMO

NOx and CH3SH as two typical air pollutants widely coexist in various energy and industrial processes; hence, it is urgent to develop highly efficient catalysts to synergistically eliminate NOx and CH3SH. However, the catalytic system for synergistically eliminating NOx and CH3SH is seldom investigated to date. Meanwhile, the deactivation effects of CH3SH on catalysts and the formation mechanism of toxic byproducts emitted from the synergistic catalytic elimination reaction are still vague. Herein, selective synergistic catalytic elimination (SSCE) of NOx and CH3SH via engineering deep oxidation sites over Cu-modified Nb-Fe composite oxides supported on TiO2 catalyst against toxic CO and HCN byproducts formation has been originally demonstrated. Various spectroscopic and microscopic characterizations demonstrate that the sufficient chemisorbed oxygen species induced by the persistent electron transfer from Nb-Fe composite oxides to copper oxides can deeply oxidize HCOOH to CO2 for avoiding highly toxic byproducts formation. This work is of significance in designing superior catalysts employed in more complex working conditions and sheds light on the progress in the SSCE of NOx and sulfur-containing volatile organic compounds.


Assuntos
Poluentes Atmosféricos , Óxidos , Oxirredução , Óxidos/análise , Óxidos/química , Oxigênio , Transporte de Elétrons , Catálise , Amônia/química
4.
Mol Divers ; 27(3): 1297-1308, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35831728

RESUMO

The Signal Transducer and Activator of Transcription 3 (STAT3) protein is activated consistently in the tumor cells and thus studied as a potent target for cancer prevention. The TYR705-phosphorylated (pTyr) STAT3 forms a homo-dimer by binding to its recognition site in the Src Homology 2 (SH2) domain of another STAT3 monomer, causing cellular survival, proliferation, inflammation, and tumor invasion. Many inhibitors of STAT3-SH2 have recently been identified using both computational and experimental approaches. In this study, we used molecular docking, Absorption, Distribution, Metabolism, and Excretion/Toxicological (ADME/tox) and molecular dynamics modeling to examine binding affinities and specificities of 191 inhibitor drugs from the SELLECKCHEM database. The binding free energies of the inhibitors were calculated by Induced Fit Docking (IFD) prime energy. The binding hotspots of STAT3-SH2 were evaluated via binding energy decomposition and hydrogen bond distribution analysis, and the inhibitor compound's stability was assessed through MD simulation. (-)-Epigallocatechin gallate, Kaempferol-3-O-rutinoside, Picroside I, Saikosaponin D, and Ginsenoside Rk1 were found to be the top hit inhibitor compounds. They exhibited an exceptional docking score, a low binding free energy, interacted with the key amino acid residue, and showed significant ADME/tox moderation. These compounds were further proved to be favorable by their stability in an MD simulation run for 100 ns using GROMACS software. The inhibitors (-)-Epigallocatechin gallate, Kaempferol-3-O-rutinoside, and Saikosaponin D show improved stability in molecular dynamic modeling and are expected to have a significant STAT3-SH2 inhibitory effect against cancer.


Assuntos
Fator de Transcrição STAT3 , Domínios de Homologia de src , Simulação de Dinâmica Molecular , Simulação de Acoplamento Molecular
5.
Environ Sci Technol ; 56(6): 3678-3688, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35195408

RESUMO

Catalytic ozonation of methyl mercaptan (CH3SH) can effectively control this unbearable odorous sulfur-containing volatile organic compound (S-VOC). The construction of an electronic metal-support interaction (EMSI) coordination structure to maximize the number of active sites and increase the intrinsic activity of active sites is an effective means to improve catalytic performance. In this work, the abundant Si-OH groups on PSBA-15 (SBA-15 before calcination) were used to anchor Mn to form a Si-O-Mn-based EMSI coordination structure. Detailed characterizations and theoretical simulations reveal that the strong EMSI effect significantly adjusts and stabilizes the electronic structure of Mn 3d states, resulting in an electron-rich center on the Si-O-Mn bond to promote the specific adsorption/activation of ozone (O3) and an electron-poor center on the (Si-O-)Mn-O bond to adsorb a large amount of CH3SH accompanied by its own oxidative degradation. In situ Raman and in situ Fourier transform infrared (FTIR) analyses identify that catalytic ozonation over 3.0Mn-PSBA generates atomic oxygen species (AOS/*O) and reactive oxygen species (ROS/•O2-) to achieve efficient decomposition of CH3SH into CO2/SO42-. Furthermore, the electrons obtained from CH3SH in electron-poor centers are transferred to maintain the redox cycle of Mn2+/3+ → Mn4+ → Mn2+/3+ through the internal bond bridge, thus accomplishing the efficient and stable degradation of CH3SH prolonged to 180 min. Therefore, the rational design of catalysts with abundant active sites and optimized inherent activity via the EMSI effect can provide significant potential to improve catalytic performance and eliminate odorous gases.

6.
Int J Mol Sci ; 23(4)2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35216282

RESUMO

Molecular biology combined with genomics can be a powerful tool for developing potential intervention strategies for improving outcomes in children with autism spectrum disorders (ASD). Monogenic etiologies rarely cause autism. Instead, ASD is more frequently due to many polygenic contributing factors interacting with each other, combined with the epigenetic effects of diet, lifestyle, and environment. One limitation of genomics has been identifying ways of responding to each identified gene variant to translate the information to something clinically useful. This paper will illustrate how understanding the function of a gene and the effects of a reported variant on a molecular level can be used to develop actionable and targeted potential interventions for a gene variant or combinations of variants. For illustrative purposes, this communication highlights a specific genomic variant, SHANK3. The steps involved in developing molecularly genomically targeted actionable interventions will be demonstrated. Cases will be shared to support the efficacy of this strategy and to show how clinicians utilized these targeted interventions to improve ASD-related symptoms significantly. The presented approach demonstrates the utility of genomics as a part of clinical decision-making.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Transtornos Cromossômicos , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/terapia , Transtorno Autístico/genética , Criança , Deleção Cromossômica , Transtornos Cromossômicos/genética , Humanos , Proteínas do Tecido Nervoso/genética
7.
Medicina (Kaunas) ; 59(1)2022 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-36676695

RESUMO

Background and objectives: It has been shown that electromagnetic fields (EMFs) have negative effects on the reproductive system. The biological effects of EMF on the male reproductive system are controversial and vary depending on the frequency and exposure time. Although a limited number of studies have focused on the structural and functional effects of EMF, the effects of prenatal and postnatal EMF exposure on testes are not clear. We aimed to investigate the effects of 50-Hz, 3-mT EMF exposure (5 days/wk, 4 h/day) during pre- and postnatal periods on testis development. Materials and Methods: Pups from three groups of Sprague-Dawley pregnant rats were used: Sham, EMF-28 (EMF-exposure applied during pregnancy and until postnatal day 28), EMF-42 (EMF-exposure applied during pregnancy and until postnatal day 42). The testis tissues and blood samples of male offspring were collected on the postnatal day 42. Results: Morphometric analyses showed a decrease in seminiferous tubule diameter as a result of testicular degeneration in the EMF-42 group. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were decreased in the EMF-42 group. Lipid peroxidation levels were increased in both EMF groups, while antioxidant levels were decreased only in the EMF-28 group. We found decreased levels of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF1) in the EMF-42 group, and decreased levels of the SRC homology 3 (SH3) and multiple ankyrin repeat domain (SHANK3) in the EMF-28 group in the testis tissue. Conclusions: EMF exposure during pre- and postnatal periods may cause deterioration in the structure and function of testis and decrease in growing factors that would affect testicular functions in male rat pups. In addition to the oxidative stress observed in testis, decreased SHANK3, VEGF, and IGF1 protein levels suggests that these proteins may be mediators in testis affected by EMF exposure. This study shows that EMF exposure during embryonic development and adolescence can cause apoptosis and structural changes in the testis.


Assuntos
Campos Eletromagnéticos , Fator A de Crescimento do Endotélio Vascular , Gravidez , Feminino , Ratos , Animais , Masculino , Campos Eletromagnéticos/efeitos adversos , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular/metabolismo , Testículo/metabolismo , Hormônio Foliculoestimulante , Vitaminas
8.
Molecules ; 25(15)2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32752073

RESUMO

Signal transducer and activator of transcription 3 (STAT3) is a validated anticancer target due to the relationship between its constitutive activation and malignant tumors. Through a virtual screening approach on the STAT3-SH2 domain, 5,6-dimethyl-1H,3H-2,1,3-benzothiadiazole-2,2-dioxide (1) was identified as a potential STAT3 inhibitor. Some benzothiadiazole derivatives were synthesized by employing a versatile methodology, and they were tested by an AlphaScreen-based assay. Among them, benzosulfamide 1 showed a significant activity with an IC50 = 15.8 ± 0.6 µM as a direct STAT3 inhibitor. Notably, we discovered that compound 1 was also able to interact with cysteine residues located around the SH2 domain. By applying mass spectrometry, liquid chromatography, NMR, and UV spectroscopy, an in-depth investigation was carried out, shedding light on its intriguing and unexpected mechanism of interaction.


Assuntos
Fator de Transcrição STAT3/metabolismo , Tiadiazóis/química , Sítios de Ligação , Desenho de Fármacos , Humanos , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética , Relação Estrutura-Atividade , Tiadiazóis/metabolismo , Tiadiazóis/farmacologia , Domínios de Homologia de src
9.
J Biol Chem ; 293(35): 13553-13565, 2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-29980598

RESUMO

Mixed-lineage kinase 3 (MLK3; also known as MAP3K11) is a Ser/Thr protein kinase widely expressed in normal and cancerous tissues, including brain, lung, liver, heart, and skeletal muscle tissues. Its Src homology 3 (SH3) domain has been implicated in MLK3 autoinhibition and interactions with other proteins, including those from viruses. The MLK3 SH3 domain contains a six-amino-acid insert corresponding to the n-Src insert, suggesting that MLK3 may bind additional peptides. Here, affinity selection of a phage-displayed combinatorial peptide library for MLK3's SH3 domain yielded a 13-mer peptide, designated "MLK3 SH3-interacting peptide" (MIP). Unlike most SH3 domain peptide ligands, MIP contained a single proline. The 1.2-Å crystal structure of the MIP-bound SH3 domain revealed that the peptide adopts a ß-hairpin shape, and comparison with a 1.5-Å apo SH3 domain structure disclosed that the n-Src loop in SH3 undergoes an MIP-induced conformational change. A 1.5-Å structure of the MLK3 SH3 domain bound to a canonical proline-rich peptide from hepatitis C virus nonstructural 5A (NS5A) protein revealed that it and MIP bind the SH3 domain at two distinct sites, but biophysical analyses suggested that the two peptides compete with each other for SH3 binding. Moreover, SH3 domains of MLK1 and MLK4, but not MLK2, also bound MIP, suggesting that the MLK1-4 family may be differentially regulated through their SH3 domains. In summary, we have identified two distinct peptide-binding sites in the SH3 domain of MLK3, providing critical insights into mechanisms of ligand binding by the MLK family of kinases.


Assuntos
MAP Quinase Quinase Quinases/metabolismo , Peptídeos/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Humanos , MAP Quinase Quinase Quinases/química , Simulação de Acoplamento Molecular , Biblioteca de Peptídeos , Peptídeos/química , Ligação Proteica , Domínios de Homologia de src , MAP Quinase Quinase Quinase 11 Ativada por Mitógeno
10.
J Environ Manage ; 220: 136-141, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29777996

RESUMO

Odor pollution from landfills is causing a growing number of public complaints and concerns. Compared with hydrogen sulfide (H2S) and ammonia (NH3), odor impacts of trace sulfur compounds (TSCs) are arousing concerns due to their low odor threshold values (OTVs). Working face on landfill sites has been claimed as major source of odor impacts. This study estimated the odor impacts of fugitive TSCs from the working face of a large typical municipal solid waste (MSW) landfill in Beijing, China. A modified wind tunnel system was introduced to estimate emission rates of TSCs, which is a basic requirement for odor impact assessment. The odor activity value (OAV) method was introduced for odor evaluation. Fieldwork in the selected landfill was conducted from 2014 to 2015. Methyl mercaptan (CH3SH), dimethyl sulfide, dimethyl disulfide (DMDS), and carbon disulfide (CS2) were the TSCs studied in this work. The spatial concentration distributions of the TSCs were calculated on the basis of the Gaussian dispersion model in a "normal case" scenario and a "worst case" scenario. DMDS showed the highest emission rate (7.18 µg m-2 s-1), and CH3SH was the dominant odorous compound with an average emission rate of 4.58 µg m-2 s-1. The dispersion modeling indicated that the odor impact distances of the TSCs in the studied landfill for the normal case and worst case scenarios were 495 ±â€¯96 m and 9230 m at the downwind regions, respectively. Results of this study can benefit the formulation of strategies for odor control and abatement in landfill sites.


Assuntos
Poluentes Atmosféricos , Odorantes , Compostos de Enxofre , Instalações de Eliminação de Resíduos , Pequim , China , Monitoramento Ambiental , Eliminação de Resíduos
11.
Genetics ; 226(1)2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-37793087

RESUMO

Protein-protein interactions (PPIs) drive many cellular processes. Some interactions are directed by Src homology 3 (SH3) domains that bind proline-rich motifs on other proteins. The evolution of the binding specificity of SH3 domains is not completely understood, particularly following gene duplication. Paralogous genes accumulate mutations that can modify protein functions and, for SH3 domains, their binding preferences. Here, we examined how the binding of the SH3 domains of 2 paralogous yeast type I myosins, Myo3 and Myo5, evolved following duplication. We found that the paralogs have subtly different SH3-dependent interaction profiles. However, by swapping SH3 domains between the paralogs and characterizing the SH3 domains freed from their protein context, we find that very few of the differences in interactions, if any, depend on the SH3 domains themselves. We used ancestral sequence reconstruction to resurrect the preduplication SH3 domains and examined, moving back in time, how the binding preference changed. Although the most recent ancestor of the 2 domains had a very similar binding preference as the extant ones, older ancestral domains displayed a gradual loss of interaction with the modern interaction partners when inserted in the extant paralogs. Molecular docking and experimental characterization of the free ancestral domains showed that their affinity with the proline motifs is likely not the cause for this loss of binding. Taken together, our results suggest that a SH3 and its host protein could create intramolecular or allosteric interactions essential for the SH3-dependent PPIs, making domains not functionally equivalent even when they have the same binding specificity.


Assuntos
Proteínas , Domínios de Homologia de src , Sequência de Aminoácidos , Simulação de Acoplamento Molecular , Proteínas/metabolismo , Prolina/química , Ligação Proteica , Sítios de Ligação/genética
12.
Environ Sci Pollut Res Int ; 31(16): 24398-24411, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38441737

RESUMO

CH3SH is a potential hazard to both chemical production and human health, so controlling its emissions is an urgent priority. In this work, a series of transition metal-loaded H-ZSM-5 adsorbents (Si/Al = 25) (Cu, Fe, Co, Ni, Mn, and Zn) were synthesized through the wet impregnation method and tested for CH3SH physicochemical adsorption at 60 °C. It was shown that the Cu-modified H-ZSM-5 adsorbent was much more active for CH3SH removal due to its abundant strong acid sites than other transition metal-modified H-ZSM-5 adsorbents. The detailed physicochemical properties of various modified H-ZSM-5 adsorbents were characterized by SEM, XRD, N2 physisorption, XPS, H2-TPR, and NH3-TPD. The effects of metal loading mass ratio, calcination temperature, and acid or alkali modification on the performance of the adsorbent were also investigated, and finally 20% Cu/ZSM-5 was found to have the best adsorption capacity after calcined at 350 °C. Additionally, the Cu/ZSM-5 adsorbent modified by sodium bicarbonate could expose more active components, which improved the adsorbent's stability. However, the consumption and reduction of the active component Cu2+ and the accumulation of sulfate during the adsorption process are the main reasons for the deactivation of the adsorbent. In addition, the simultaneous purging of N2 + O2 can effectively restore the adsorption capacity of the deactivated adsorbent and can be used as a potential strategy to regenerate the adsorbent.


Assuntos
Elementos de Transição , Humanos , Adsorção , Cobre/química , Temperatura
13.
J Hazard Mater ; 469: 133871, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38428301

RESUMO

Due to the typical volatility of gaseous pollutant methyl mercaptan (CH3SH), the development of a facile, reliable, and accurate onsite environmental surveillance of highly toxic CH3SH faces many challenges, but it is critical to environmental atmosphere assessment and safeguarding public health. Here, we prepared a novel bimetallic carbon dots (Fe&Cu@CDs) nanozyme with high peroxidase-mimicking activity to design a portable hydrogel kit for onsite visual H2O2-self-supplying enzymatic cascade catalytic colorimetric and photothermal signal synergistic amplification dual-modal monitoring of CH3SH in atmospheric environment. Assisted by alcohol oxidase (AOX), CH3SH could be specifically converted into H2O2 for oxidizing chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) catalyzed by Fe&Cu@CDs to produce dark blue ox-TMB with absorption at 652 nm and photothermal characters. Consequently, a CH3SH concentration-dependent change both in naked-eye color and photothermal effect-triggered temperature were observed. By hybridizing AOX-assisted Fe&Cu@CDs + TMB with agarose, a H2O2-self-supplying colorimetric and photothermal signal synergistic amplification sensory hydrogel kit integrated with Color Picker APP-installed smartphone and 660 nm laser-equipped handheld thermal imager for CH3SH was proposed with acceptable results in atmospheric environment around wastepile (e.g., solid waste and food waste piles), which exhibited great potentials to further develop commercial onsite monitoring platforms in warning-early abnormal atmospheric CH3SH for safeguarding environmental health.


Assuntos
Peróxido de Hidrogênio , Eliminação de Resíduos , Carbono , Hidrogéis , Alimentos , Colorimetria/métodos
14.
Heliyon ; 10(15): e35480, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39165974

RESUMO

Receptor tyrosine kinase (RTK) overexpression is linked to the development and progression of multiple cancers. RTKs are classically considered to initiate cytoplasmic signalling pathways via ligand-induced tyrosine phosphorylation, however recent evidence points to a second tier of signalling contingent on interactions mediated by the proline-rich motif (PRM) regions of non-activated RTKs. The presence of PRMs on the C-termini of >40 % of all RTKs and the abundance of PRM-binding proteins encoded by the human genome suggests that there is likely to be a large number of previously unexplored interactions which add to the RTK intracellular interactome. Here, we explore the RTK PRM interactome and its potential significance using affinity purification mass spectrometry and in silico enrichment analyses. Peptides comprising PRM-containing C-terminal tail regions of EGFR, FGFR2 and HER2 were used as bait to affinity purify bound proteins from different cancer cell line lysates. 490 unique interactors were identified, amongst which proteins with metabolic, homeostatic and migratory functions were overrepresented. This suggests that PRMs from RTKs may sustain a diverse interactome in cancer cells. Since RTK overexpression is common in cancer, RTK PRM-derived signalling may be an important, but as yet underexplored, contributor to negative cancer outcomes including resistance to kinase inhibitors.

15.
Nanomaterials (Basel) ; 13(4)2023 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-36839143

RESUMO

As a representative sulfur-containing volatile organic compounds (S-VOCs), CH3SH has attracted widespread attention due to its adverse environmental and health risks. The performance of Mn-based catalysts and the effect of their crystal structure on the CH3SH catalytic reaction have yet to be systematically investigated. In this paper, two different crystalline phases of tunneled MnO2 (α-MnO2 and ß-MnO2) with the similar nanorod morphology were used to remove CH3SH, and their physicochemical properties were comprehensively studied using high-resolution transmission electron microscope (HRTEM) and electron paramagnetic resonance (EPR), H2-TPR, O2-TPD, Raman, and X-ray photoelectron spectroscopy (XPS) analysis. For the first time, we report that the specific reaction rate for α-MnO2 (0.029 mol g-1 h-1) was approximately 4.1 times higher than that of ß-MnO2 (0.007 mol g-1 h-1). The as-synthesized α-MnO2 exhibited higher CH3SH catalytic activity towards CH3SH than that of ß-MnO2, which can be ascribed to the additional oxygen vacancies, stronger surface oxygen migration ability, and better redox properties from α-MnO2. The oxygen vacancies on the catalyst surface provided the main active sites for the chemisorption of CH3SH, and the subsequent electron transfer led to the decomposition of CH3SH. The lattice oxygen on catalysts could be released during the reaction and thus participated in the further oxidation of sulfur-containing species. CH3SSCH3, S0, SO32-, and SO42- were identified as the main products of CH3SH conversion. This work offers a new understanding of the interface interaction mechanism between Mn-based catalysts and S-VOCs.

16.
Saudi Dent J ; 34(3): 211-219, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35935717

RESUMO

Objective: Solobacterium moorei is suggested to be associated with the production of volatile sulphur compounds (VSCs) and can be found in subgingival plaques of deep periodontal pockets. We examined whether this bacterium's count was reduced in periodontitis patients with halitosis following non-surgical periodontal treatment, while the bacterial count of Prevotella intermedia was measured simultaneously as a control. Material & methods: This clinical study included 20 adults with chronic periodontitis who complained of halitosis. The bacterial relationship in the subgingival plaque sample was measured after 8 weeks post-treatment, including the probing pocket depth (PPD). Quantitative real-time PCR (qPCR) was used to measure the proportion of S. moorei, while the concentrations of H2S and CH3SH were determined using oral ChromaTM. Results: The presence of S. moorei was consistently observed in participants with periodontitis before and after non-surgical periodontal treatment and consistent showed a significantly lower proportion compared with P. intermedia. Solobacterium moorei showed a strong positive correlation with H2S and CH3SH concentrations, but a negative correlation with deep periodontal pocket measurements. Conversely, reduced P. intermedia may be more associated with a deep pocket, independent of the concentration of CH3SH. Conclusion: The study data showed that the proportion of S. moorei in the subgingival biofilm can be related to halitosis in periodontitis patients.

17.
J Struct Biol X ; 6: 100061, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35128378

RESUMO

Cell surface receptors such as the T-cell receptor (TCR) and B-cell receptor (BCR) engage with external stimuli to transmit information into the cell and initiate a cascade of signaling events that lead to gene expression that drives the immune response. At the heart of controlling T- and B-cell cell signaling, phospholipase Cγ hydrolyzes membrane associated PIP2, leading to generation of the second messengers IP3 and DAG. These small molecules trigger mobilization of intracellular Ca2+ and promote transcription factor transport into the nucleus launching the adaptive immune response. The TEC family kinases are responsible for phosphorylating and activating PLCγ, and our group aims to understand mechanisms that regulate immune cell signal transduction by focusing on this kinase/phospholipase axis in T-cells and B-cells. Here, we review the current molecular level understanding of how the TEC kinases (ITK and BTK) and PLCγ1/2 are autoinhibited prior to activation of cell surface receptors, how TEC kinases are activated to specifically recognize the PLCγ substrate, and how conformational changes induced by phosphorylation trigger PLCγ activation.

18.
Biomedicines ; 9(11)2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34829812

RESUMO

The multi-domain non-structural protein 3 (NSP3) is an oncogenic molecule that has been concomitantly implicated in the progression of coronavirus infection. However, its oncological role in lung cancer and whether it plays a role in modulating the tumor immune microenvironment is not properly understood. In the present in silico study, we demonstrated that NSP3 (SH2D3C) is associated with advanced stage and poor prognoses of lung cancer cohorts. Genetic alterations of NSP3 (SH2D3C) co-occurred inversely with Epidermal Growth Factor Receptor (EGFR) alterations and elicited its pathological role via modulation of various components of the immune and inflammatory pathways in lung cancer. Our correlation analysis suggested that NSP3 (SH2D3C) promotes tumor immune evasion via dysfunctional T-cell phenotypes and T-cell exclusion mechanisms in lung cancer patients. NSP3 (SH2D3C) demonstrated a high predictive value and association with therapy resistance in lung cancer, hence serving as an attractive target for therapy exploration. We evaluated the in silico drug-likeness and NSP3 (SH2D3C) target efficacy of six organosulfur small molecules from Allium sativum using a molecular docking study. We found that the six organosulfur compounds demonstrated selective cytotoxic potential against cancer cell lines and good predictions for ADMET properties, drug-likeness, and safety profile. E-ajoene, alliin, diallyl sulfide, 2-vinyl-4H-1,3-dithiin, allicin, and S-allyl-cysteine docked well into the NSP3 (SH2D3C)-binding cavity with binding affinities ranging from -4.3~-6.70 A and random forest (RF) scores ranging from 4.31~5.26 pKd. However, S-allyl-cysteine interaction with NSP3 (SH2D3C) is unfavorable and hence less susceptible to NSP3 ligandability. In conclusion, our study revealed that NSP3 is an important onco-immunological biomarker encompassing the tumor microenvironment, disease staging and prognosis in lung cancer and could serve as an attractive target for cancer therapy. The organosulfur compounds from A. sativum have molecular properties to efficiently interact with the binding site of NSP3 and are currently under vigorous preclinical study in our laboratory.

19.
3 Biotech ; 9(6): 235, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31139550

RESUMO

One of the most important rapidly emerging mosquito-borne alphavirus is Chikungunya virus (CHIKV). There is a necessity to develop anti-CHIKV therapeutics, as neither antiviral drug nor vaccines have been licensed yet. Several CHIKV proteins are being studied worldwide, but non-structural protein 3 (nsP3) has been less explored. This protein consists of three domains: macrodomain, alphavirus unique domain (AUD) and hypervariable region (HVR). The proline-rich regions of HVR contain SRC homology 3 (SH3)-binding domain which is essential for its functionality. Interaction of these motifs with host amphiphysin protein is crucial for viral RNA replication. Restricting the interactions of HVR could lead to inhibition of viral life cycle. Therefore, the present study focuses on purification of HVR protein and its structural and functional assay for therapeutic intervention in future use. In order to obtain purified protein, HVR region was amplified from TOPO clones of nsP3 of IND-06-Guj strain and cloned into expression vector. Expression and solubilization of the protein were optimized at various conditions of salt, detergent and imidazole before purification. The soluble recombinant HVR (His-HVR) protein was purified using affinity chromatography. Purified protein was analyzed for structural studies and functional assays. Circular dichroism of His-HVR protein was performed for structural study, and it was observed that it consists of mostly random coils. For functional assay, co-pull down of His-HVR protein was performed with endogenous amphiphysin-I protein of N2a cells and was analyzed using Western blotting. This purified protein obtained could be used as a potential target reagent for novel therapeutic interventions in the future.

20.
Sci Total Environ ; 648: 805-810, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30138880

RESUMO

Landfills are city infrastructures used for the treatment of municipal solid waste (MSW) in China. However, due to technical failure and/or management problem most of them are facing serious secondary pollution such as groundwater contamination and odor nuisance. The latter is the main reason causing a growing number of public complaints. Atmospheric dispersion models are routinely adopted for odor impact assessment, but these models provide deterministic predictions only. To determine the potential odorant paths and treat the uncertainty of odor pollution, Monte Carlo simulation coupled with an odor dispersion model was proposed and named Monte Carlo-dispersion simulation method (MCDSM). By introducing a series of random values of error components in the dispersion model, MCDSM can produce probabilistic odor impact results. Values of these variances were randomly selected according to their probability density functions (PDFs) due to the imprecise knowledge of the meteorological and emission conditions. After running the odor dispersion model for numerous times, the randomization produces a set of possible results that closely resembles the expected behavior of the odorants. This study applied MCDSM to estimate the odor impact of methyl mercaptan (CH3SH) on an MSW landfill in Beijing, China. The PDF of the CH3SH emission rate was derived from the field data. The uncertainty of odor impact was analyzed statistically, and the results were summarized using the probability of odor exceedance (POE). A POE map of CH3SH was plotted for a particular interest, in which the north downwind direction was the most polluted area. MCDSM provides a scientific approach for the assessment of odor pollution from individual odorant, which can benefit the formulation of standard for odor impact assessment in landfill sites.

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