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1.
Proc Natl Acad Sci U S A ; 120(15): e2212468120, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-37011215

RESUMO

Soybean (Glycine max) morphogenesis and flowering time are accurately regulated by photoperiod, which determine the yield potential and limit soybean cultivars to a narrow latitudinal range. The E3 and E4 genes, which encode phytochrome A photoreceptors in soybean, promote the expression of the legume-specific flowering repressor E1 to delay floral transition under long-day (LD) conditions. However, the underlying molecular mechanism remains unclear. Here, we show that the diurnal expression pattern of GmEID1 is opposite to that of E1 and targeted mutations in the GmEID1 gene delay soybean flowering regardless of daylength. GmEID1 interacts with J, a key component of circadian Evening Complex (EC), to inhibit E1 transcription. Photoactivated E3/E4 interacts with GmEID1 to inhibit GmEID1-J interaction, promoting J degradation resulting in a negative correlation between daylength and the level of J protein. Notably, targeted mutations in GmEID1 improved soybean adaptability by enhancing yield per plant up to 55.3% compared to WT in field trials performed in a broad latitudinal span of more than 24°. Together, this study reveals a unique mechanism in which E3/E4-GmEID1-EC module controls flowering time and provides an effective strategy to improve soybean adaptability and production for molecular breeding.


Assuntos
Flores , Glycine max , Glycine max/genética , Glycine max/metabolismo , Flores/genética , Flores/metabolismo , Fotoperíodo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
2.
Phys Chem Chem Phys ; 26(6): 5558-5568, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38284214

RESUMO

Rare base-pairs consists of guanine (G) paired with rare bases, such as 5-methylcytosine (5-meCyt), 5-hydroxymethylcytosine (5-hmCyt), 5-carboxylcytosine (5-caCyt), and 5-formylcytosine (5-fCyt), have become the focus of epigenetic research because they can be used as markers to detect some chronic diseases and cancers. However, the correlation detection of these rare base-pairs is limited, which in turn limits the development of diagnostic tests and devices. Herein, the interaction of rare base-pairs adsorbed on pure and B/N-doped γ-graphyne (γ-GY) nanosheets was explored using the density functional theory. The calculated adsorption energy showed that the system of rare base-pairs on B-doped γ-GY is more stable than that on pure γ-GY or N-doped γ-GY. Translocation time values indicate that rare base-pairs can be successfully distinguished as the difference in their translocation times is very large for pure and B/N-doped γ-GY nanosheets. Meanwhile, sensing response values illustrated that pure and B-doped γ-GY are the best for G-5-hmCyt adsorption, while the N-doped γ-GY is the best for G-Cyt adsorption. The findings indicate that translocation times and sensing response can be used as detection indexes for pure and B/N doped γ-GY, which will provide a new way for experimental scientists to develop the biosensor components.


Assuntos
Adsorção , Pareamento de Bases
3.
Environ Res ; 248: 118137, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38295972

RESUMO

Since nitrate nitrogen (NO3--N) input has proved an effective approach for the treatment of black and odorous river waterbody, it was controversial whether the total nitrogen concentration standard should be raised when the effluent from the sewage treatment plant is discharged into the polluted river. To reveal the effect of exogenous nitrate (NO3--N) on black odorous waterbody, sediments with different features from contaminated rivers were collected, and the changes of physical and chemical characteristics and microbial community structure in sediments before and after the addition of exogenous NO3--N were investigated. The results showed that after the input of NO3--N, reducing substances such as acid volatile sulfide (AVS) in the sediment decreased by 80 % on average, ferrous (Fe2+) decreased by 50 %, yet the changing trend of ammonia nitrogen (NH4+-N) in some sediment samples increased while others decreased. High-throughput sequencing results showed that the abundance of Thiobacillus at most sites increased significantly, becoming the dominant genus in the sediment, and the abundance of functional genes in the metabolome increased, such as soxA, soxX, soxY, soxZ. Network analysis showed that sediment microorganisms evolved from a single sulfur oxidation ecological function to diverse ecological functions, such as nitrogen cycle nirB, nirD, nirK, nosZ, and aerobic decomposition. In summary, inputting an appropriate amount of exogenous NO3--N is beneficial for restoring and maintaining the oxidation states of river sediment ecosystems.


Assuntos
Microbiota , Nitratos , Nitrogênio/análise
4.
Clin Oral Implants Res ; 35(3): 258-267, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38031528

RESUMO

OBJECTIVES: This study aims at examining the correlation of intraosseous temperature change with drilling impulse data during osteotomy and establishing real-time temperature prediction models. MATERIALS AND METHODS: A combination of in vitro bovine rib model and Autonomous Dental Implant Robotic System (ADIR) was set up, in which intraosseous temperature and drilling impulse data were measured using an infrared camera and a six-axis force/torque sensor respectively. A total of 800 drills with different parameters (e.g., drill diameter, drill wear, drilling speed, and thickness of cortical bone) were experimented, along with an independent test set of 200 drills. Pearson correlation analysis was done for linear relationship. Four machining learning (ML) algorithms (e.g., support vector regression [SVR], ridge regression [RR], extreme gradient boosting [XGboost], and artificial neural network [ANN]) were run for building prediction models. RESULTS: By incorporating different parameters, it was found that lower drilling speed, smaller drill diameter, more severe wear, and thicker cortical bone were associated with higher intraosseous temperature changes and longer time exposure and were accompanied with alterations in drilling impulse data. Pearson correlation analysis further identified highly linear correlation between drilling impulse data and thermal changes. Finally, four ML prediction models were established, among which XGboost model showed the best performance with the minimum error measurements in test set. CONCLUSION: The proof-of-concept study highlighted close correlation of drilling impulse data with intraosseous temperature change during osteotomy. The ML prediction models may inspire future improvement on prevention of thermal bone injury and intelligent design of robot-assisted implant surgery.


Assuntos
Implantes Dentários , Procedimentos Cirúrgicos Robóticos , Robótica , Animais , Bovinos , Implantes Dentários/efeitos adversos , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Desenho de Equipamento , Osteotomia/efeitos adversos , Implantação Dentária Endóssea/efeitos adversos , Temperatura Alta
5.
J Prosthet Dent ; 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38760310

RESUMO

A digital workflow for the rapid design and fabrication of interim fixed prostheses using an open-access software program and 3-dimensional printing technology is described. After obtaining intraoral scanning data, the prostheses are designed by offset, margin sculpting, and a Boolean operation. Then, the prostheses are finalized and manufactured additively. The use of the open-access software program and simplified design steps enhances the manufacturing efficiency and accessibility of computer-aided design and computer-aided manufacturing of interim restorations.

6.
New Phytol ; 237(5): 1794-1809, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36352516

RESUMO

Isoflavones are a class of secondary metabolites produced by legumes and play important roles in human health and plant stress tolerance. The C2H2 zinc-finger transcription factor (TF) functions in plant stress tolerance, but little is known about its function in isoflavone regulation in soybean (Glycine max). Here, we report a C2H2 zinc-finger TF gene, GmZFP7, which regulates isoflavone accumulation in soybean. Overexpressing GmZFP7 increased the isoflavone concentration in both transgenic hairy roots and plants. By contrast, silencing GmZFP7 expression significantly reduced isoflavone levels. Metabolomic and qRT-PCR analysis revealed that GmZFP7 can increase the flux of the phenylpropanoid pathway. Furthermore, dual-luciferase and electrophoretic mobility shift assays showed that GmZFP7 regulates isoflavone accumulation by influencing the expression of Isoflavone synthase 2 (GmIFS2) and Flavanone 3 ß-hydroxylase 1 (GmF3H1). In this study, we demonstrate that GmZFP7 contributes to isoflavone accumulation by regulating the expression of the gateway enzymes (GmIFS2 and GmF3H1) of competing phenylpropanoid pathway branches to direct the metabolic flux into isoflavone. A haplotype analysis indicated that important natural variations were present in GmZFP7 promoters, with P-Hap1 and P-Hap3 being the elite haplotypes. Our findings provide insight into how GmZFP7 regulates the phenylpropanoid pathway and enhances soybean isoflavone content.


Assuntos
Glycine max , Isoflavonas , Humanos , Glycine max/metabolismo , Isoflavonas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica de Plantas , Zinco/metabolismo
7.
Theor Appl Genet ; 136(1): 13, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36662254

RESUMO

KEY MESSAGE: We identified four hub genes for isoflavone biosynthesis based on BSA-seq and WGCNA methods and validated that GmIE3-1 positively contribute to isoflavone accumulation in soybean. Soybean isoflavones are secondary metabolites of great interest owing to their beneficial impact on human health. Herein, we profiled the seed isoflavone content by HPLC in 1551 soybean accessions grown in two locations for two years and constructed two extreme pools with high (4065.1 µg g-1) and low (1427.23 µg g-1) isoflavone contents to identify candidate genes involved in isoflavone biosynthesis pathways using bulk segregant analysis sequencing (BSA-seq) approach. The results showed that the average sequencing depths were 50.3× and 65.7× in high and low pools, respectively. A total of 23,626 polymorphic SNPs and 5299 InDels were detected between both pools and 1492 genes with different variations were identified. Based on differential genes in BSA-seq and weighted gene co-expression network analysis (WGCNA), four hub genes, Glyma.06G290400 (designated as GmIE3-1), Glyma.01G239200, Glyma.01G241500, Glyma.13G256100 were identified, encoding E3 ubiquitin-protein ligase, arm repeat protein interacting with ABF2, zinc metallopeptidase EGY3, and dynamin-related protein 3A, respectively. The allelic variation in GmIE3-1 showed a significant influence on isoflavone accumulation. The virus-induced gene silencing (VIGS) and RNAi hairy root transformation of GmIE3-1 revealed partial suppression of this gene could cause a significant decrease (P < 0.0001) of total isoflavone content, suggesting GmIE3-1 is a positive regulator for isoflavones. The present study demonstrated that the BSA-seq approach combined with WGCNA, VIGS and hairy root transformation can efficiently identify isoflavone candidate genes in soybean natural population.


Assuntos
Genes de Plantas , Glycine max , Isoflavonas , Sementes , Humanos , Isoflavonas/genética , Polimorfismo de Nucleotídeo Único , Sementes/genética , Sementes/metabolismo , Glycine max/genética , Glycine max/metabolismo
8.
Theor Appl Genet ; 136(7): 149, 2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37294438

RESUMO

KEY MESSAGE: From 61 QTL mapped, a stable QTL cluster of 992 kb was discovered on chromosome 5 for folate content and a putative candidate gene, Glyma.05G237500, was identified. Folate (vitamin B9) is one of the most essential micronutrients whose deficiencies lead to various health defects in humans. Herein, we mapped the quantitative trait loci (QTL) underlying seed folate content in soybean using recombinant inbred lines developed from cultivars, ZH35 and ZH13, across four environments. We identified 61 QTL on 12 chromosomes through composite interval mapping, with phenotypic variance values ranging from 1.68 to 24.68%. A major-effect QTL cluster (qFo-05) was found on chromosome 5, spanning 992 kb and containing 134 genes. Through gene annotation and single-locus haplotyping analysis of qFo-05 in a natural soybean population, we identified seven candidate genes significantly associated with 5MTHF and total folate content in multiple environments. RNA-seq analysis showed a unique expression pattern of a hemerythrin RING zinc finger gene, Glyma.05G237500, between both parental cultivars during seed development, which suggest the gene might regulate folate content in soybean. This is the first study to investigate QTL underlying folate content in soybean and provides new insight for molecular breeding to improve folate content in soybean.


Assuntos
Glycine max , Locos de Características Quantitativas , Humanos , Mapeamento Cromossômico , Sementes
9.
J Fluoresc ; 33(2): 653-661, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36480126

RESUMO

Accurate monitoring of intracellular pH in living cells is critical for developing a better understanding of cellular activities. In the current study, label-free carbon dots (p-CDs), which were fabricated using a straightforward one-pot solvothermal treatment of p-phenylenediamine and urea, were employed to create a new ratiometric pH nanosensor. Under single-wavelength excitation (λex = 500 nm), the p-CDs gave dual emission bands at 525 and 623 nm. The fluorescent intensity ratio (I525/I623) was linearly related to pH over the range 4.0 to 8.8 in buffer solutions, indicating that the ratiometric fluorescence nanoprobe may be useful for pH sensing. In pH measurements, the p-CDs also demonstrated outstanding selectivity, reversibility, and photostability. Owing to the advantages outlined above, the nanoprobe was used to monitor the pH of HeLa cells effectively. The label-free CD-based ratiometric nanoprobe features comparatively easy manufacturing and longer excitation and emission wavelengths than the majority of previously reported CD-based ratiometric pH sensors, which is ultimately beneficial for applications in biological imaging.


Assuntos
Pontos Quânticos , Humanos , Células HeLa , Carbono , Corantes Fluorescentes , Concentração de Íons de Hidrogênio
10.
Phys Chem Chem Phys ; 25(15): 10472-10480, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-36987569

RESUMO

Graphyne (GY) and functionalized GY have become cutting-edge research materials for the scientific community. In the present work, the adsorption of rare bases -cytosine (Cyt), 5-methylcytosine (5-meCyt), 5-hydroxymethylcytosine (5-hmCyt), 5-formoxylcytosine (5-fCyt), and 5-carboxylcytosine (5-caCyt) on pristine, B- and N-doped γ-GY was investigated by the first-principles density functional method; methods were designed to distinguish these rare bases by the translocation time and sensitivity. Initially, the stability of pristine, B- and N-doped γ-GY was ascertained by the cohesion energy, and the electronic properties were also analyzed by the energy gap and density of state (DOS). When adsorbing over pristine γ-GY, the translocation times of rare bases were 1.34 × 101, 4.71 × 101, 1.19 × 104, 3.77 × 10-1 and 1.93 × 101 s, respectively. The sensitivities were 2.19%, 0.88%, 0.22%, 2.41%, and 0.88%, respectively, which indicates that they were not clearly separated. By doping the impurity atom, the electronic properties can be fine-tuned to change their selectivity. When adsorbing on the B-doped γ-GY, these rare bases showed sensitivities of 24.69%, 27.20%, 43.32%, 29.97%, and 32.24%, respectively. The rare bases showed sensitivities of 10.15%, 9.02%, 17.29%, 0.38%, and 3.76%, respectively, when adsorbing over the N-doped γ-GY, which greatly increases selectivities for recognization. Thus, these results indicate that pristine and doped γ-GY, as the electrical sensing material, can be used to detect rare bases.


Assuntos
DNA , Eletricidade , Adsorção , Eletrônica , Simulação por Computador
11.
Appl Opt ; 62(27): 7216-7225, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37855577

RESUMO

Design technology co-optimization (DTCO) is a potential approach to tackle the escalating expenses and complexities associated with pitch scaling. This strategy offers a promising solution by minimizing the required design dimensions and mitigating the pitch scaling trend. It is worth noting that lithography has played a significant role in dimensional scaling over time. This paper proposes a DTCO flow to reduce the impact of the process variation (PV) band and edge placement error (EPE). First, we performed the digital back-end design of the high-performance processor and got the test layout; second, we executed timing analysis on the test layout to get the critical path net that affects the chip performance; third, we proposed the timing-aware optimized optical proximity correction (OPC) method to optimize the PV band and EPE by adjusting the weights of critical path net merit points, optimizing the generation of the sub-resolution assistant feature, giving tighter EPE specs for merit points on the critical path net, and placing denser merit points as well as denser breakpoints for the critical path net to obtain greater freedom in the OPC process. Finally, it is verified that our proposed DTCO process can significantly reduce the EPE and lead to a slight decrease in the PV band of the chip while maintaining the same process windows.

12.
Angew Chem Int Ed Engl ; 62(22): e202302365, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-36973174

RESUMO

Synthesis of highly stable two-dimensional single-layer assemblies (SLAs) is a key challenge in supramolecular science, especially those with long-range molecular order and well-defined morphology. Here, thin (thickness <2 nm) triangular AuI -thiolate SLAs with high thermo-, solvato- and mechano- stability have been synthesized via a double-ligand co-assembly strategy. Furthermore, the SLAs show assembly-level elastic and anisotropic deformation responses to external stimuli as a result of the long-range anisotropic molecular packing, which provides SLAs with new application potentials in bio-mimic nanomechanics.

13.
Anal Chem ; 94(50): 17485-17493, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36480597

RESUMO

Hypochlorous acid (HOCl) and peroxynitrite (ONOO-) are two important highly reactive oxygen/nitrogen species, which commonly coexist in biosystems and play pivotal roles in many physiological and pathological processes. To investigate their function and correlations, it is urgently needed to construct chemical tools that can track the production of HOCl and ONOO- in biological systems with distinct fluorescence signals. Here, we found that the coumarin fluorescence of coumarin-benzopyrylium (CB) hydrazides (spirocyclic form) is dim, and their fluorescence properties are controlled by their benzopyran moiety via an intramolecular photo-induced electron transfer (PET) process. Based on this mechanism, we report the development of a fluorescent probe CB2-H for the simultaneous detection of HOCl and ONOO-. ONOO- can selectively oxidize the hydrazide group of CB2-H to afford the parent dye CB2 (Absmax/Emmax = 631/669 nm). In the case of HOCl, it undergoes an electrophilic attack on the benzopyran moiety of CB2-H to give a chlorinated product CB2-H-Cl, which inhibits the PET process within the probe and thus affords a turn-on fluorescence response at the coumarin channel (Absmax/Emmax = 407/468 nm). Due to the marked differences in absorption/emission wavelengths between the HOCl and ONOO- products, CB2-H enables the concurrent detection of HOCl and ONOO- at two independent channels without spectral cross-interference. CB2-H has been applied for dual-channel fluorescence imaging of endogenously produced HOCl and ONOO- in living cells and zebrafish under different stimulants. The present probe provides a useful tool for further exploring the distribution and correlation of HOCl and ONOO- in more biosystems.


Assuntos
Corantes Fluorescentes , Ácido Peroxinitroso , Animais , Corantes Fluorescentes/química , Ácido Peroxinitroso/química , Ácido Hipocloroso/química , Peixe-Zebra , Espécies Reativas de Nitrogênio , Imagem Óptica , Cumarínicos/química
14.
Chemistry ; 28(67): e202201968, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36000183

RESUMO

Two-dimensional (2D) Au(I)-thiolate assemblies are a special type of material that can balance high structural stability and rich surface functionality, which shows promising prospects in both fundamental research and applications. Co-assembly of multiple ligands is a facile way to further enrich the surface properties and functions, and expand their application potentials. In this work, taking 3-mercaptopropionic acid (MPA), cysteine (Cys) and 1-thioglycerol (TGO) as example ligands, we studied in detail the possibility to co-assemble them into one nanosheet. Although the three ligands have significantly different controllability and pathways when self-assembling individually with Au(I), they can still be effectively co-assembled by reacting with HAuCl4 together to obtain three-ligand nanosheets with good colloidal stability. The key points for successful co-assembly are also revealed by comparing single- and three-ligand self-assembly processes, laying a solid foundation for co-assembly of even more ligands. The easy but powerful strategy for 2D materials with closely-packed and multiple tunable surface functional groups addresses the surface engineering problem for 2D materials and paves the way for their wider applications in sensing and biomaterials.


Assuntos
Materiais Biocompatíveis , Ligantes , Propriedades de Superfície
15.
Plant Cell Environ ; 44(8): 2551-2564, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34050544

RESUMO

Soybean (Glycine max), a typical short-day plant (SDP) domesticated in temperate regions, has expanded to high latitudes where daylengths are long from soybean emergence to bloom, but rapidly decrease from seed filling to maturity. Cotyledons are well known as the major storage organs in seeds, but it is unclear whether developing cotyledons store flowering substances at filling stage in SD for upcoming seedlings, or instead respond to photoperiod for floral induction after emergence of matured seeds in long-day (LD). Here, we report that cotyledons accelerate flowering of early-maturing varieties not resulting from stored floral stimuli but by perceiving photoperiod after emergence. We found that light signal is indispensable to activate cotyledons for floral induction, and flowering promoting gene GmFT2a is required for cotyledon-dependent floral induction via upregulation of floral identity gene GmAP1. Interestingly, cotyledons are competent to support the entire life cycle of a cotyledon-only plant to produce seeds, underlying a new photoperiod study system in soybean and other dicots. Taken together, these results demonstrate a substantial role for cotyledons in flowering process, whereby we propose a 'cotyledon-based self-reliance' model highlighting floral induction from emergence as a key ecological adaptation for rapid flowering of SDPs grown in LD environments at high latitudes.


Assuntos
Adaptação Fisiológica , Cotilédone/fisiologia , Glycine max/fisiologia , China , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Luz , Fotoperíodo , Plantas Geneticamente Modificadas , Proteínas de Soja/genética
16.
Mikrochim Acta ; 186(7): 468, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31240486

RESUMO

New green-emissive carbon dots (G-CDs) are described here and shown to be viable fluorescent nanoprobes for the detection of changes in cellular pH values. By using m-phenylenediamine as the carbon source, G-CDs with an absolute quantum yield of 36% were solvothermally synthesized in the presence of strong H2SO4. The G-CDs have an average size of 2.3 nm and display strong fluorescence with excitation/emission peaks at 450/510 nm. The fluorescence intensity depends on the pH value in the range from 6.0 to 10.0, affording the capability for sensitive detection of intracellular pH variation. The nanosensor with excellent photostability exhibited good fluorescence reversibility in different pH solutions, and showed excellent stability against the influence of other biological species. The nanoprobe was successfully used in confocal fluorescence microscopy to determine pH values in SMMC-7721 cells. Graphical abstract Schematic presentation of green-emissive carbon dots (G-CDs) synthesized using m-phenylenediamine and sufuric acid through a solvothermal method for real-time fluorometric monitoring of intracellular pH values. Mechanism can be ascribed to PET process from the electron lone pair in amino group to the CDs.


Assuntos
Corantes Fluorescentes/química , Pontos Quânticos/química , Carbono/química , Carbono/toxicidade , Linhagem Celular Tumoral , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Humanos , Concentração de Íons de Hidrogênio , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Fenilenodiaminas/química , Pontos Quânticos/toxicidade
17.
Anal Chem ; 90(6): 4119-4125, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29466857

RESUMO

Selenocysteine (Sec) is a primary kind of reactive selenium species in cells, and its vital roles in physiological processes have been featured. Thus, the development of highly sensitive and selective methods for the sensing of Sec is of great significance. This work reports a turn-on fluorescent probe for selenol based on the unique fluorescence OFF-ON switching between the Schiff base (SB) and its complementary protonated Schiff base (PSB) form of merocyanine dyes. The probe consists of a merocyanine Schiff base fluorophore and a 2,4-dinitrobenzenesulfonamide moiety that reacts especially with selenol. The fluorescence turn-on response of MC-Sec is realized via the selective removal of the strongly electron withdrawing 2,4-dinitrobenzenesulfonyl group by Sec, leading to a shift in the p Ka of the imine nitrogen of the probe from 6.40 to 9.04 and thus significantly increasing the population of the fluorescent PSB form of the dye at physiological pH. MC-Sec shows good selectivity and sensitivity for Sec and has been applied in the imaging of exogenous and endogenous selenol in living cells by confocal fluorescence microscopy. The proposed mechanism should be useful for developing future probes directed to other target molecules by employing this simple but effective p Ka shift strategy.


Assuntos
Benzopiranos/química , Corantes Fluorescentes/química , Indóis/química , Imagem Óptica/métodos , Compostos de Selênio/análise , Linhagem Celular , Fluorescência , Humanos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Bases de Schiff/química , Espectrometria de Fluorescência/métodos
18.
Anal Chem ; 90(4): 2946-2953, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29347818

RESUMO

Vicinal dithiol-containing proteins (VDPs) play fundamental roles in intracellular redox homeostasis and are responsible for many diseases. In this work, we report a far-red fluorescence turn-on probe MCAs for VDPs exploiting the pKa shift of the imine functionality of the probe. MCAs is composed of a merocyanine Schiff base as the fluorescent reporter and a cyclic 1,3,2-dithiarsenolane as the specific ligand for VDPs. The imine pKa of MCAs is 4.8, and it exists predominantly in the Schiff base (SB) form at physiological pH. Due to the absence of a resonating positive charge, it absorbs at a relatively short wavelength and is essentially nonfluorescent. Upon selective binding to reduced bovine serum albumin (rBSA, selected as the model protein), MCAs was brought from aqueous media to the binding pockets of the protein, causing a large increase in pKa value of MCAs (pKa = 7.1). As a result, an increase in the protonated Schiff base (PSB) form of MCAs was observed at the physiological pH conditions, which in turn leads to a bathochromically shifted chromophore (λabs = 634 nm) and a significant increase in fluorescence intensity (λem = 657 nm) simultaneously. Furthermore, molecular dynamics simulations indicate that the salt bridges formed between the iminium in MCAs and the residues D72 and D517 in rBSA resist the dissociation of proton from the probe, thus inducing an increase of the pKa value. The proposed probe shows excellent sensitivity and specificity toward VDPs over other proteins and biologically relevant species and has been successfully applied for imaging of VDPs in living cells. We believe that the present pKa shift switching strategy may facilitate the development of new fluorescent probes that are useful for a wide range of applications.

19.
Anal Chem ; 89(3): 1734-1741, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28208245

RESUMO

Selenocysteine (Sec) carries out the majority of the functions of the various Se-containing species in vivo. Thus, it is of great importance to develop sensitive and selective assays to detect Sec. Herein, a carbon-dot-based fluorescent turn-on probe for highly selective detection of selenol in living cells is presented. The highly photoluminescent carbon dots that emit yellow-green fluorescence (Y-G-CDs; λmax = 520 nm in water) were prepared by using m-aminophenol as carbon precursor through a facile solvothermal method. The surface of Y-G-CDs was then covalently functionalized with 2,4-dinitrobenzenesulfonyl chloride (DNS-Cl) to afford the 2,4-dinitrobenzene-functionalized CDs (CD-DNS) as a nanoprobe for selenol. CD-DNS is almost nonfluorescent. However, upon treating with Sec, the DNS moiety of CD-DNS can be readily cleaved by selenolate through a nucleophilic substitution process, resulting in the formation of highly fluorescent Y-G-CDs and hence leads to a dramatic increase in fluorescence intensity. The proposed nanoprobe exhibits high sensitivity and selectivity toward Sec over biothiols and other biological species. A preliminary study shows that CD-DNS can function as a useful tool for fluorescence imaging of exogenous and endogenous selenol in living cells.


Assuntos
Carbono/química , Corantes Fluorescentes/química , Microscopia de Fluorescência , Pontos Quânticos/química , Compostos de Selênio/análise , Aminofenóis/química , Animais , Linhagem Celular , Dinitrobenzenos/química , Concentração de Íons de Hidrogênio , Camundongos , Compostos de Selênio/química
20.
Theor Appl Genet ; 130(7): 1467-1479, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28389769

RESUMO

KEY MESSAGE: We constructed a high-density linkage map comprising 3541 markers developed by specific-locus amplified fragment sequencing, and identified 26 stable QTL including nine novel loci, for fatty acid composition in soybean. Soybean oil quality and stability are mainly determined by the fatty acid composition of the seed. In the present study, we constructed a high-density genetic linkage map using 200 recombinant inbred lines derived from a cross between cultivated soybean varieties Luheidou2 and Nanhuizao, and SNP markers developed by specific-locus amplified fragment sequencing (SLAF-seq). This map comprises 3541 markers on 20 linkage groups and spans a genetic distance of 2534.42 cM, with an average distance of 0.72 cM between adjacent markers. Inclusive composite interval mapping revealed 26 stable QTL for five fatty acids, explaining 0.4-37.0% of the phenotypic variance for individual fatty acids across environments. Of these QTL, nine are novel loci (qLA1, qLNA2_1, qPA4_1, qLA4_1, qPA6_1, qSA12_1, qPA16_1, qOA18_1, and qFA19_1). These stable QTL harbor three fatty acid biosynthesis genes (GmFabG, GmACP, and GmFAD8), and 66 genes encoding lipid-related transcription factors. These stable QTL and tightly linked SNP markers can be used for marker-assisted selection in soybean breeding programs.


Assuntos
Mapeamento Cromossômico , Ácidos Graxos/química , Glycine max/genética , Locos de Características Quantitativas , Epistasia Genética , Ligação Genética , Marcadores Genéticos , Genótipo , Fenótipo , Polimorfismo de Nucleotídeo Único , Sementes/química , Análise de Sequência de DNA/métodos
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