RESUMO
Light is a major environmental factor for seed germination. Red light-activated phytochrome B (phyB) promotes seed germination by modulating the dynamic balance of two phytohormones, gibberellic acid (GA) and abscisic acid (ABA). How phyB modulates ABA biosynthesis after perceiving a light signal is not yet well understood. Here, we identified the noncoding RNA HIDDEN TREASURE 1 (HID1) as a repressor of ABA biosynthesis acting downstream of phyB during Arabidopsis thaliana seed germination. Loss of HID1 function led to delayed phyB-dependent seed germination. Photoactivated phyB promoted the accumulation of HID1 in the radicle within 48 h of imbibition. Our transcriptomics analysis showed that HID1 and phyB co-regulate the transcription of a common set of genes involved in ABA and GA metabolism. Through a forward genetic screen, we identified three ABA biosynthesis genes, ABA DEFICIENT 1 (ABA1), ABA2, and ABA3, as suppressors of HID1. We further demonstrated that HID1 directly inhibits the transcription of 9-CIS-EPOXYCAROTENOID DIOXYGENASE (NCED9), a gene encoding a key rate-limiting enzyme of ABA biosynthesis. HID1 interacts with ARABIDOPSIS TRITHORAX-RELATED7 (ATXR7), an H3K4me3 methyltransferase, inhibiting its occupancy and H3K4me3 modification at the NCED9 locus. Our study reveals a nuclear mechanism of phyB signaling transmitted through HID1 to control the internal homeostasis of ABA and GA, which gradually optimizes the transcriptional network during seed germination.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico/metabolismo , Fitocromo B/genética , Fitocromo B/metabolismo , Proteínas de Arabidopsis/metabolismo , Germinação/genética , Sementes/genética , Sementes/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Giberelinas/metabolismo , Regulação da Expressão Gênica de Plantas/genéticaRESUMO
Ambient light and the endogenous circadian clock play key roles in regulating Arabidopsis (Arabidopsis thaliana) seedling photomorphogenesis. PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) acts downstream of both light and the circadian clock to promote hypocotyl elongation. Several members of the R2R3-MYB transcription factor (TF) family, the most common type of MYB TF family in Arabidopsis, have been shown to be involved in regulating photomorphogenesis. Nonetheless, whether R2R3-MYB TFs are involved in connecting the light and clock signaling pathways during seedling photomorphogenesis remains unknown. Here, we report that MYB112, a member of the R2R3-MYB family, acts as a negative regulator of seedling photomorphogenesis in Arabidopsis. The light signal promotes the transcription and protein accumulation of MYB112. myb112 mutants exhibit short hypocotyls in both constant light and diurnal cycles. MYB112 physically interacts with PIF4 to enhance the transcription of PIF4 target genes involved in the auxin pathway, including YUCCA8 (YUC8), INDOLE-3-ACETIC ACID INDUCIBLE 19 (IAA19), and IAA29. Furthermore, MYB112 directly binds to the promoter of LUX ARRHYTHMO (LUX), the central component of clock oscillators, to repress its expression mainly in the afternoon and relieve LUX-inhibited expression of PIF4. Genetic evidence confirms that LUX acts downstream of MYB112 in regulating hypocotyl elongation. Thus, the enhanced transcript accumulation and transcriptional activation activity of PIF4 by MYB112 additively promotes the expression of auxin-related genes, thereby increasing auxin synthesis and signaling and fine-tuning hypocotyl growth under diurnal cycles.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Relógios Circadianos , Fitocromo , Arabidopsis/metabolismo , Relógios Circadianos/genética , Hipocótilo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Plântula/genética , Fitocromo/genética , Fitocromo/metabolismo , Ácidos Indolacéticos/metabolismo , Regulação da Expressão Gênica de Plantas , LuzRESUMO
The master transcriptional repressor DREAM (dimerization partner, RB-like, E2F and multivulval class B) complex regulates the cell cycle in eukaryotes, but much remains unknown about how it transmits repressive signals on chromatin to the primary transcriptional machinery (e.g., RNA polymerase II [Pol II]). Through a forward genetic screen, we identified BTE1 (barrier of transcription elongation 1), a plant-specific component of the DREAM complex. The subsequent characterization demonstrated that DREAM complex containing BTE1 antagonizes the activity of Complex Proteins Associated with Set1 (COMPASS)-like complex to repress H3K4me3 occupancy and inhibits Pol II elongation at DREAM target genes. We showed that BTE1 is recruited to chromatin at the promoter-proximal regions of target genes by E2F transcription factors. DREAM target genes exhibit characteristic enrichment of H2A.Z and H3K4me2 modification on chromatin. We further showed that BTE1 directly interacts with WDR5A, a core component of COMPASS-like complex, repressing WDR5A chromatin binding and the elongation of transcription on DREAM target genes. H3K4me3 is known to correlate with the Pol II transcription activation and promotes efficient elongation. Thus, our study illustrates a transcriptional repression mechanism by which the DREAM complex dampens H3K4me3 deposition at a set of genes through its interaction with WDR5A.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Histonas , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Transporte/metabolismo , Cromatina/genética , Cromatina/metabolismo , Histonas/genética , Histonas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
With the extensive use of fossil fuels, the ever-increasing greenhouse gas of mainly carbon dioxide emissions will result in global climate change. It is of utmost importance to reduce carbon dioxide emissions and its utilization. Li-CO2 batteries can convert carbon dioxide into electrochemical energy. However, developing efficient catalysts for the decomposition of Li2 CO3 as the discharge product represents a challenge in Li-CO2 batteries. Herein, we demonstrate a carbon foam composite with growing carbon nanotube by using cobalt as the catalyst, showing the ability to enhance the decomposition rate of Li2 CO3 , and thus improve the electrochemical performance of Li-CO2 batteries. Benefiting from its abundant pore structure and catalytic sites, the as-assembled Li-CO2 battery exhibits a desirable overpotential of 1.67â V after 50â cycles. Moreover, the overpotentials are 1.05 and 2.38â V at current densities of 0.02 and 0.20â mA cm-2 , respectively. These results provide a new avenue for the development of efficient catalysts for Li-CO2 batteries.
RESUMO
For non-small cell lung cancer patients with dual mutations in EGFR and ALK, there are currently no effective therapies. Consequently, novel EGFR/ALK dual-target inhibitors are urgently needed for the treatment of NSCLC. Here, we designed a series of highly effective small molecule dual inhibitors of ALK and EGFR. The biological evaluation highlighted that most of these new compounds could effectively inhibit both ALK and EGFR in enzymatic and cellular assays. Compound (+)-8l was investigated for its antitumor properties, and it was found that (+)-8l blocked the phosphorylation of EGFR and ALK induced by ligands and inhibited phosphorylation-ERK and phosphorylation-AKT induced by ligands. Furthermore, (+)-8l also induces apoptosis and G0/G1 cell cycle arrest in cancer cells and inhibits proliferation, migration, and invasion. Notably, (+)-8l significantly suppressed tumor growth in the H1975 cell-inoculated xenograft model (20 mg/kg/d, TGI: 96.11%), PC9 cell-inoculated xenograft model (20 mg/kg/d, TGI: 96.61%) and EML4 ALK-Baf3 cell-inoculated xenograft model (30 mg/kg/d, TGI: 80.86%). These results highlight the differentiated potential of (+)-8l to inhibit ALK rearrangement and EGFR mutation in NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Ligantes , Receptores ErbB , Fosforilação , Mutação , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Linhagem Celular Tumoral , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismoRESUMO
The unique extracellular electron transfer (EET) ability has positioned electroactive bacteria (EAB) as a major class of cellular chassis for genetic engineering aimed at favorable environmental, energy, and geoscience applications. However, previous efforts to genetically enhance EET ability have often impaired the basal metabolism and cellular growth due to the competition for the limited cellular resource. Here, we design a quorum sensing-based population-state decision (PSD) system for intelligently reprogramming the EET regulation system, which allows the rebalanced allocation of the cellular resource upon the bacterial growth state. We demonstrate that the electron output from Shewanella oneidensis MR-1 could be greatly enhanced by the PSD system via shifting the dominant metabolic flux from initial bacterial growth to subsequent EET enhancement (i.e., after reaching a certain population-state threshold). The strain engineered with this system achieved up to 4.8-fold EET enhancement and exhibited a substantially improved pollutant reduction ability, increasing the reduction efficiencies of methyl orange and hexavalent chromium by 18.8- and 5.5-fold, respectively. Moreover, the PSD system outcompeted the constant expression system in managing EET enhancement, resulting in considerably enhanced electron output and pollutant bioreduction capability. The PSD system provides a powerful tool for intelligently managing extracellular electron transfer and may inspire the development of new-generation smart bioelectrical devices for various applications.
Assuntos
Transporte de Elétrons/fisiologia , Shewanella/fisiologia , Respiração Celular/fisiologia , Cromo/metabolismo , Elétrons , Percepção de Quorum/fisiologia , Shewanella/metabolismoRESUMO
The interactions of human CYP3A4 with three selected isomer flavonoids, such as astilbin, isoastilbin and neoastilbin, were clarified using spectral analysis, molecular docking, and molecular dynamics simulation. During binding with the three flavonoids, the intrinsic fluorescence of CYP3A4 was statically quenched in static mode with nonradiative energy conversion. The fluorescence and ultraviolet/visible (UV/vis) data revealed that the three flavonoids had a moderate and stronger binding affinity with CYP3A4 due to the order of the Ka1 and Ka2 values ranging from 104 to 105 L·mol-1 . In addition, astilbin had the highest affinity with CYP3A4, then isoastilbin and neoastilbin, at the three experimental temperatures. Multispectral analysis confirmed that binding of the three flavonoids resulted in clear changes in the secondary structure of CYP3A4. It was found from fluorescence, UV/vis and molecular docking analyses that these three flavonoids strongly bound to CYP3A4 by means of hydrogen bonds and van der Waals forces. The key amino acids around the binding site were also elucidated. Furthermore, the stabilities of the three CYP3A4 complexes were evaluated using molecular dynamics simulation.
Assuntos
Citocromo P-450 CYP3A , Flavonoides , Humanos , Simulação de Acoplamento Molecular , Flavonoides/química , Sítios de Ligação , Termodinâmica , Ligação Proteica , Espectrometria de Fluorescência/métodos , Dicroísmo CircularRESUMO
In this work, interaction mechanism of narcissoside with two α-amylase from Bacillus subtilis (BSA) and Porcine pancreatic (PPA) are comparatively studied by multi-spectral analysis, molecular docking and molecular dynamics simulation. The results prove that narcissoside can statically quench fluorescence of BSA/PPA. Two complexes are mainly formed by hydrogen bond and van der Waals force. With the increase of temperature, the two complexes formed by narcissoside and two enzymes become unstable. At the same experimental temperature, the binding force of narcissoside to PPA is higher than that of BSA. The binding of narcissoside to PPA/BSA increases the hydrophobicity of microenvironment. Moreover, the secondary structure of PPA/BSA is mainly changed by decreasing the α-helix. The optimal binding modes of narcissoside with BSA/PPA are predicted by molecular docking, and the stability of the two complexes is evaluated by molecular dynamics simulations.
RESUMO
ALK-positive NSCLC coexisting with EGFR mutations is a frequently occurring clinical phenomenon. Targeting ALK and EGFR simultaneously may be an effective way to treat these cancer patients. In this study, we designed and synthesized ten new dual-target EGFR/ALK inhibitors. Among them, the optimal compound 9j exhibited good activity with IC50 values of 0.07829 ± 0.03 µM and 0.08183 ± 0.02 µM against H1975 (EGFR T790M/L858R) and H2228 (EML4-ALK) cells, respectively. Immunofluorescence assays indicated that the compound could simultaneously inhibit the expression of phosphorylated EGFR and ALK proteins. A kinase assay demonstrated that compound 9j could inhibit both EGFR and ALK kinases; thus, exerting an antitumor effect. Additionally, compound 9j induced apoptosis in a dose-dependent manner and inhibited the invasion and migration of tumor cells. All of these results indicate that 9j is worthy of further study.
Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Receptores ErbB/metabolismo , Receptores Proteína Tirosina Quinases , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Mutação , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Antineoplásicos/farmacologiaRESUMO
Genetic engineering is promising to expand the application scope of exoelectrogens in energy and environmental applications and plasmid vectors, as one type of fundamental tool, are intensively applied. Antibiotics are widely utilized for plasmid selection and maintenance; however, their utilization suffers from environmental concerns on the spread of resistance genes, elevated costs, inevitable genotypic instability and phenotypic heterogeneity. In this work, we establish an auxotrophic complementation system for stable plasmid maintenance without antibiotic association, in Shewanella oneidensis, an attractive model exoelectrogen. A plasmid-transition strategy is designed to facilitate the rapid and efficient construction of the auxotrophic complementation system. Such a system not only enables the same intensive gene expression as the conventional antibiotic-associated plasmid system but also exhibits remarkably superior robustness and stability. With this system, the menaquinone pool of the extracellular respiratory chain is enhanced first independently and further synergized by engineering the Mtr conduit, leading to significantly promoted extracellular electron transfer (EET) outputs (up to 10.33- and 2.97-fold improvement in the maximum current density and the maximum output voltage) and heavy metal Cr(VI) reduction ability (5.15-fold improvement). This work provides a robust and stable platform to engineer exoelectrogens for environmental applications.
Assuntos
Shewanella , Shewanella/genética , Shewanella/metabolismo , Plasmídeos/genética , Transporte de Elétrons , Respiração Celular , Antibacterianos/metabolismoRESUMO
The interaction mechanism of pelargonidin (PG) with tyrosinase was investigated by multi-spectroscopy and molecular docking. As a result, PG had strong inhibitory activity on tyrosinase with the IC50 value of 41.94 × 10-6 mol·L-1 . The inhibition type of PG against tyrosinase was determined as a mixed-mode. Meanwhile, the fluorescence of tyrosinase was quenched statically by PG, and accompanied by non-radiative energy transfer. The three-dimensional (3-D) fluorescence, ultraviolet-visible spectroscopy (UV-Vis) and circular dichroism spectroscopies (CD) indicated that PG decreased the hydrophobicity of the micro-environment around tryptophan (Trp) and tyrosine (Tyr), which resulted in the conformational change of tyrosinase. In addition, fluorescence and molecular docking analysis indicated that PG bound to tyrosinase via hydrogen bonds (H-bonds) and van der Waals force (vdW force). We herein recommended that PG might be a potential candidate drug for the treatment of melanin-related diseases.
Assuntos
Monofenol Mono-Oxigenase , Antocianinas , Sítios de Ligação , Dicroísmo Circular , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase/química , Monofenol Mono-Oxigenase/metabolismo , Espectrometria de Fluorescência/métodos , Análise Espectral , TermodinâmicaRESUMO
The critical T790M secondary mutation in epidermal growth-factor receptor (EGFR) mediates resistance to first- and second-generation EGFR tyrosine kinase inhibitors. Herein, we identified 12 new 2,4-diaryl pyrimidine derivatives containing thiophene fragments as new selective third-generation EGFR inhibitors. Among them, Compound 6a showed good inhibitory activity against EGFR mutant cells with an IC50 value of 0.0022 ± 0.001 µM and was approximately 1730-fold less potent against EGFR WT cells (IC50: 4.499 ± 0.057 µM). Moreover, it strongly affected EGFR-mediated signaling pathways, attenuated tumor proliferation via the intrinsic mitochondrial apoptotic pathway, arrested the cell cycle at G0/G1 phase, and induced apoptosis in H1975 cells. It also displayed appropriate pharmacokinetic (PK) parameters with an oral bioavailability value of 33.57%. Additionally, in vivo studies confirmed that 6a suppressed tumor growth in an H1975 xenograft model (25 mg/kg/d, TGI: 90.24%). Overall, these results suggest that 6a could be a promising lead compound for overcoming the clinical EGFR T790M resistance of patients with non-small-cell lung cancers (NSCLCs).
Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Mutação , Inibidores de Proteínas Quinases/metabolismo , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Relação Estrutura-AtividadeRESUMO
The inhibitory effects of delphinidin-3-O-galactoside (DG) on the activities of tyrosinase (EC 1.14.18.1) (TY) from the edible Agaricus bisporus mushroom were investigated by enzyme kinetics, multispectroscopic methods, and molecular docking. As a result, DG showed strong inhibition on TY with the IC50 of 34.14 × 10-6 mol L-1 . The inhibition mode of DG against TY was mixed type with α values of 5.09. The binding constant Ka and related thermodynamic parameters at the three different temperatures showed that the fluorescence quenching of TY by DG was static quenching. Synchronous fluorescence, three-dimensional fluorescence, ultraviolet-visible spectroscopy, and circular dichroism spectroscopies confirmed that the conformation or microenvironment of the TY protein were changed after binding with DG. Molecular docking revealed that DG had strong binding affinity to TY through hydrogen bonding and van der Waals force, and the results were consistent with the fluorescence data. Our findings suggested that DG may be potential TY inhibitor.
Assuntos
Galactosídeos , Monofenol Mono-Oxigenase , Antocianinas , Dicroísmo Circular , Simulação de Acoplamento Molecular , Espectrometria de Fluorescência/métodos , Espectrofotometria UltravioletaRESUMO
Researchers have established a classification model based on tear Raman spectroscopy combined with machine learning classification algorithms, which realizes rapid noninvasive classification of cerebral infarction and cerebral ischemia, which is of great significance for clinical medical diagnosis. Through spectral data analysis, it is found that there are differences in the content of tyrosine, phenylalanine, and carotenoids in the tears of patients with cerebral ischemia and patients with cerebral infarction. We try to establish a classification model for rapid noninvasive screening of cerebral infarction and cerebral ischemia through these differences. The experiment has four parts, including normalization, data enhancement, feature extraction, and data classification. The researchers combined three feature extraction methods with four machine classification models to build a total of 12 classification models. Integrating 8 classification criteria, the classification accuracy of all models is above 85%, especially PLS-PNN has achieved 100% accuracy and better running time. The experimental results show that tear Raman spectroscopy combined with machine learning classification model has a good effect on the screening of cerebral ischemia and cerebral infarction, which is conducive to the noninvasive and rapid clinical diagnosis of cerebrovascular diseases in the future.
Assuntos
Isquemia Encefálica , Análise Espectral Raman , Algoritmos , Isquemia Encefálica/diagnóstico por imagem , Infarto Cerebral/diagnóstico por imagem , Humanos , Aprendizado de Máquina , Máquina de Vetores de SuporteRESUMO
The advances in synthetic biology bring exciting new opportunities to reprogram microorganisms with novel functionalities for environmental applications. For real-world applications, a genetic tool that enables genetic engineering in a stably genomic inherited manner is greatly desired. In this work, we design a novel genetic device for rapid and efficient genome engineering based on the intron-encoded homing-endonuclease empowered genome editing (iEditing). The iEditing device enables rapid and efficient genome engineering in Shewanella oneidensis MR-1, the representative strain of the electroactive bacteria group. Moreover, combining with the Red or RecET recombination system, the genome-editing efficiency was greatly improved, up to approximately 100%. Significantly, the iEditing device itself is eliminated simultaneously when genome editing occurs, thereby requiring no follow-up to remove the encoding system. Then, we develop a new extracellular electron transfer (EET) engineering strategy by programming the parallel EET systems to enhance versatile EET. The engineered strains exhibit sufficiently enhanced electron output and pollutant reduction ability. Furthermore, this device has demonstrated its great potential to be extended for genome editing in other important microbes. This work provides a useful and efficient tool for the rapid generation of synthetic microorganisms for various environmental applications.
Assuntos
Fontes de Energia Bioelétrica/microbiologia , Elétrons , Engenharia Genética/métodos , Genoma Bacteriano/genética , Biodegradação Ambiental , Transporte de Elétrons/genética , Poluentes Ambientais/metabolismo , Edição de Genes/instrumentação , Engenharia Genética/instrumentação , Recombinação Genética , Shewanella/genética , Shewanella/metabolismoRESUMO
Anaplastic lymphoma kinase (ALK) targeted therapies have demonstrated remarkable efficacy in ALK-positive lung adenocarcinomas. Here we synthesized and evaluated sixteen new 2,4-diaminopyrimidines bearing a sulfoxide moiety as anaplastic lymphoma kinase (ALK) inhibitors. The optimal compound 9e exhibited excellent antiproliferative activity against non-small cell lung cancer NCI-H2228 cells, which is better than that of Brigatinib and similar to Ceritinib. Mechanism study revealed that the optimal compound 9e decreased the mitochondrial membrane potential and arrested NCI-H2228 cells in the G0/G1 phase, finally resulting in cellular apoptosis. It is interesting that 9e could effectively inhibit the migration of NCI-H2228 cells and may be a promising leading compound for chemotherapy of metastatic cancer.
Assuntos
Quinase do Linfoma Anaplásico/antagonistas & inibidores , Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Safrol/análogos & derivados , Quinase do Linfoma Anaplásico/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirimidinas/síntese química , Pirimidinas/química , Safrol/química , Safrol/farmacologia , Relação Estrutura-AtividadeRESUMO
Dissimilatory metal-reducing bacteria (DMRB) with extracellular electron transfer (EET) capability show great potential in bioremediating the subsurface environments contaminated by uranium through bioreduction and precipitation of hexavalent uranium [U(VI)]. However, the low EET efficiency of DMRB remains a bottleneck for their applications. Herein, we develop an engineered CRISPR platform to drive the extracellular electron pumping of Shewanella oneidensis, a representative DMRB species widely present in aquatic environments. The CRISPR platform allows for highly efficient and multiplex genome editing and rapid platform elimination post-editing in S. oneidensis. Enabled by such a platform, a genomic promoter engineering strategy (GPS) for genome-widely engineering the EET-encoding gene network was established. The production of electron conductive Mtr complex, synthesis of electron shuttle flavin, and generation of NADH as intracellular electron carrier are globally optimized and promoted, leading to a significantly enhanced EET ability. Applied to U(VI) bioreduction, the edited strains achieve up to 3.62-fold higher reduction capacity over the control. Our work endows DMRB with an enhanced ability to remediate the radionuclides-contaminated environments and provides a gene editing approach to handle the growing environmental challenges of radionuclide contaminations.
Assuntos
Shewanella , Urânio , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Transporte de Elétrons , Elétrons , Shewanella/genéticaRESUMO
Astilbin, neoastilbin and isoastilbin are three flavonoid isomers from Smilacis glabrae Roxb. (S. glabrae). Several studies have shown that consumption of flavonoids can increase the risk of food/drug-drug interaction by affecting the activities of human cytochrome CYP3A4 and 2D6. In the present study, an ultrahigh-performance liquid chromatography and triple quadrupole mass spectrometry method was developed for the determination of the interaction between three flavonoid isomers and two CYPs. Under the optimized reaction conditions, the Km values were 18.9 and 36.4 µM and the Vmax values were 0.02 and 0.20 µM/min for CYP3A4 and 2D6 in vitro, respectively. Astilbin showed the strongest inhibition on CYP3A4, followed by isoastilbin and neoastilbin with IC50 values of 2.63, 3.03 and 6.51 µM. Neoastilbin showed the strongest inhibition on CYP2D6, followed by isoastilbin and astilbin, with IC50 values of 1.48, 11.87 and 14.16 µM, respectively. The three isomers showed reversible inhibition on both enzymes. Neoastilbin and astilbin were noncompetitive type for CYP3A4 and 2D6, isoastilbin was a mixture and noncompetitive type for CYP3A4 and 2D6, respectively. Our study suggests that the three isomers may increase the risk of food/drug-drug interactions by affecting the activities of CYP3A4 and 2D6.
Assuntos
Citocromo P-450 CYP2D6 , Inibidores do Citocromo P-450 CYP3A/farmacologia , Citocromo P-450 CYP3A , Flavonoides/farmacologia , Flavonóis/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Citocromo P-450 CYP2D6/análise , Citocromo P-450 CYP2D6/efeitos dos fármacos , Citocromo P-450 CYP2D6/metabolismo , Citocromo P-450 CYP3A/análise , Citocromo P-450 CYP3A/efeitos dos fármacos , Citocromo P-450 CYP3A/metabolismo , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Espectrometria de Massas em TandemRESUMO
Astilbin, isoastilbin and neoastilbin are the three flavonoid isomers prevalent in Rhizoma Smilax glabra. The interactions between human cytochrome P450 2D6 (CYP2D6) and the three isomers were investigated by multiple spectroscopic coupled with molecular docking. As a result, the fluorescence intensity of CYP2D6 was quenched statically by the three isomers. Meanwhile, astilbin had the strongest binding ability to CYP2D6, followed by isoastilbin and neoastilbin under the identical temperature. Synchronous fluorescence, three-dimensional fluorescence, ultraviolet-visible spectroscopy, circular dichroism and Fourier-transform infrared spectra confirmed that the conformation and micro-environment of CYP2D6 protein were changed after binding with the three isomers. As suggested from molecular docking, the three isomers had strong binding affinity to CYP2D6 via the bonding of hydrogen and van der Waals forces, and the results were in agreement with the fluorescence results. The findings here suggested that astilbin, isoastilbin and neoastilbin may cause the herb-drug interactions for their inhibition of CYP2D6 activity.
Assuntos
Citocromo P-450 CYP2D6 , Flavonoides , Sítios de Ligação , Dicroísmo Circular , Flavonóis , Humanos , Ligação de Hidrogênio , Simulação de Acoplamento Molecular , Ligação Proteica , Espectrometria de Fluorescência , TermodinâmicaRESUMO
Prussian blue (PB) and its analogues are recognized as promising cathodes for rechargeable batteries intended for application in low-cost and large-scale electric energy storage. With respect to PB cathodes, however, their intrinsic crystal regularity, vacancies, and coordinated water will lead to low specific capacity and poor rate performance, impeding their application. Herein, nanocubic porous Nax FeFe(CN)6 coated with polydopamine (PDA) as a coupling layer to improve its electrochemical performance is reported, inspired by the excellent adhesive property of PDA. As a cathode for sodium-ion batteries, the Nax FeFe(CN)6 electrode coupled with PDA delivers a reversible capacity of 93.8 mA h g-1 after 500 cycles at 0.2 A g-1 , and a discharge capacity of 72.6 mA h g-1 at 5.0 A g-1 . The sodium storage mechanism of this Nax FeFe(CN)6 coupled with PDA is revealed via in situ Raman spectroscopy. The first-principles computational results indicate that FeII sites in PB prefer to couple with the robust PDA layer to stabilize the PB structure. Moreover, the sodium-ion migration in the PB structure is enhanced after coating with PDA, thus improving the sodium storage properties. Both experiments and computational simulations present guidelines for the rational design of nanomaterials as electrodes for energy storage devices.