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1.
J Environ Manage ; 357: 120775, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38569263

RESUMO

The present study aimed to assess the efficiency of zeolite in mitigating the nitrogen (N) losses through ammonia (NH3) and nitrous oxide (N2O) emissions from pig slurry (PS) applied to Italian ryegrass (IRG)-maize fields under a crop rotation system and the consequent effect on nitrogen use efficiency (NUE) for forage production. PS was applied at rates of 150 and 200 kg N ha-1 for the IRG and maize growing seasons, respectively, with or without zeolite. Soil mineral N content and NH3 and N2O emissions were measured periodically throughout the year-round cultivation of IRG and maize. Forage yield and nutritional composition were also analyzed at the harvest time of each crop. The PS with/without zeolite application effects were interpreted by comparison with those obtained for the negative control (no-N fertilization). Soil ammonium (NH4+) content in the PS-applied plots sharply increased within the first week, then progressively decreased in both the IRG and maize growing seasons. Soil NH4+ contents in the zeolite-amended plots were higher compared to the treatment without zeolite except for the first 1 or 2 weeks after PS application when soil nitrate (NO3-) contents significantly decreased. The increase in soil NH4+ content as affected by zeolite application was more distinct in the maize growing season than in the IRG growing season. NH3 emission was predominant at the early 2 weeks after PS application. Zeolite application reduced the cumulative emission of NH3 from PS by 16.7% and 24.4% and that of N2O by 15.6% and 31.5% in the IRG growing and maize growing seasons, respectively. NUE for dry matter (DM) and total digestible nutrients (TDN) production significantly improved in annual yield basis of the IRG-maize cropping. Zeolite application in PS-applied field may represent effective management in mitigating N losses through odorous NH3 and greenhouse gas (N2O) emissions, thereby improving NUE forage production.


Assuntos
Lolium , Zeolitas , Animais , Suínos , Nitrogênio , Zea mays , Solo , Óxido Nitroso/análise , Fertilizantes , Produção Agrícola , Itália , Agricultura
2.
Angew Chem Int Ed Engl ; 62(42): e202309852, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37635684

RESUMO

Conventional solid electrolyte frameworks typically consist of anions such as sulphur, oxygen, chlorine, and others, leading to inherent limitations in their properties. Despite the emergence of sulphide, oxide, and halide-based solid electrolytes for all-solid-state batteries, their utilization is hampered by issues, including the evolution of H2 S gas, the need for expensive elements, and poor contact. Here, we first introduce Prussian Blue analogue (PBA) open-framework structures as a solid electrolyte that demonstrates appreciable Na+ conductivity (>10-2 mS cm-1 ). We delve into the relationship between Na+ conductivity and the lattice parameter of N-coordinated transition metal, which is attributed to the reduced interaction between Na+ and the framework, corroborated by the distribution of relaxation times and density functional theory calculations. Among the five PBAs studied, Mn-PBA have exhibited the highest Na+ conductivity of 9.1×10-2 mS cm-1 . Feasibility tests have revealed that Mn-PBA have maintained a cycle retention of 95.1 % after 80cycles at 30 °C and a C-rate of 0.2C. Our investigation into the underlying mechanisms that play a significant role in governing the conductivity and kinetics of these materials contributes valuable insights for the development of alternative strategies to realize all-solid-state batteries.

3.
Adv Mater ; 35(38): e2303199, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37395728

RESUMO

The majority of waste-heat energy exists in the form of low-grade heat (<100 °C), which is immensely difficult to convert into usable energy using conventional energy-harvesting systems. Thermally regenerative electrochemical cycles (TREC), which integrate battery and thermal-energy-harvesting functionalities, are considered an attractive system for low-grade heat harvesting. Herein, the role of structural vibration modes in enhancing the efficacy of TREC systems is investigated. How changes in bonding covalency, influenced by the number of structural water molecules, impact the vibration modes is analyzed. It is discovered that even small amounts of water molecules can induce the A1g stretching mode of cyanide ligands with strong structural vibration energy, which significantly contributes to a larger temperature coefficient (ɑ) in a TREC system. Leveraging these insights, a highly efficient TREC system using a sodium-ion-based aqueous electrolyte is designed and implemented. This study provides valuable insights into the potential of TREC systems, offering a deeper understanding of the intrinsic properties of Prussian Blue analogs regulated by structural vibration modes. These insights open up new possibilities for enhancing the energy-harvesting capabilities of TREC systems.

4.
Nano Lett ; 23(8): 3582-3591, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37027522

RESUMO

Over the past decade, lithium metal has been considered the most attractive anode material for high-energy-density batteries. However, its practical application has been hindered by its high reactivity with organic electrolytes and uncontrolled dendritic growth, resulting in poor Coulombic efficiency and cycle life. In this paper, we propose a design strategy for interface engineering using a conversion-type reaction of metal fluorides to evolve a LiF passivation layer and Li-M alloy. Particularly, we propose a LiF-modified Li-Mg-C electrode, which demonstrates stable long-term cycling for over 2000 h in common organic electrolytes with fluoroethylene carbonate (FEC) additives and over 700 h even without additives, suppressing unwanted side reactions and Li dendritic growth. With the help of phase diagrams, we found that solid-solution-based alloying not only facilitates the spontaneous evolution of a LiF layer and bulk alloy but also enables reversible Li plating/stripping inward to the bulk, compared with intermetallic compounds with finite Li solubility.

5.
Microbiol Spectr ; 10(6): e0221522, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36219103

RESUMO

Light quality is a significant factor for living organisms that have photosensory systems, such as rhodopsin, a seven alpha-helical transmembrane protein with the retinal chromophore. Here, we report, for the first time, the function of new rhodopsin, which is an inverted 7-transmembrane protein, isolated from Trichococcus flocculiformis. T. flocculiformis heliorhodopsin (TfHeR) works as a regulatory helper rhodopsin that binds with class 2 cyclobutane pyrimidine dimer (CPDII) photolyase to broaden the spectrum and upregulate DNA repair activity. We have confirmed their interaction through isothermal titration calorimetry (dissociation constant of 21.7 µM) and identified the charged residues for the interaction. Based on in vivo and in vitro experiments, we showed that the binding of heliorhodopsin with photolyase improved photolyase activity by about 3-fold to repair UV-caused DNA damage. Also, the DNA repair activity of TfHeR/T. flocculiformis photolyase (TfPHR) was observed in the presence of green light. Our results suggested that heliorhodopsin directly controls the activity of photolyase and coevolves to broaden the activity spectrum by protein-protein interaction. IMPORTANCE This study reports a function for Heliorhodopsin working as a regulatory helper rhodopsin that with CPDII photolyase to broaden the spectrum and upregulating the DNA repair activity. Our results suggested that heliorhodopsin directly controls photolyase activity and coevolves to broaden the DNA repair capacity by protein-protein interaction.


Assuntos
Desoxirribodipirimidina Fotoliase , Desoxirribodipirimidina Fotoliase/química , Desoxirribodipirimidina Fotoliase/genética , Desoxirribodipirimidina Fotoliase/metabolismo , Rodopsina/genética , Dímeros de Pirimidina/química , Dímeros de Pirimidina/metabolismo , Reparo do DNA
6.
Commun Biol ; 5(1): 512, 2022 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-35637261

RESUMO

The position of carotenoid in xanthorhodopsin has been elucidated. However, a challenging expression of this opsin and a complex biosynthesis carotenoid in the laboratory hold back the insightful study of this rhodopsin. Here, we demonstrated co-expression of the xanthorhodopsin type isolated from Gloeobacter violaceus PCC 7421-Gloeobacter rhodopsin (GR) with a biosynthesized keto-carotenoid (canthaxanthin) targeting the carotenoid binding site. Direct mutation-induced changes in carotenoid-rhodopsin interaction revealed three crucial features: (1) carotenoid locked motif (CLM), (2) carotenoid aligned motif (CAM), and color tuning serines (CTS). Our single mutation results at 178 position (G178W) confirmed inhibition of carotenoid binding; however, the mutants showed better stability and proton pumping, which was also observed in the case of carotenoid binding characteristics. These effects demonstrated an adaptation of microbial rhodopsin that diverges from carotenoid harboring, along with expression in the dinoflagellate Pyrocystis lunula rhodopsin and the evolutionary substitution model. The study highlights a critical position of the carotenoid binding site, which significantly allows another protein engineering approach in the microbial rhodopsin family.


Assuntos
Rodopsina , Rodopsinas Microbianas , Sítios de Ligação , Carotenoides/metabolismo , Bombas de Próton , Rodopsina/genética , Rodopsina/metabolismo , Rodopsinas Microbianas/genética , Rodopsinas Microbianas/metabolismo
7.
Nano Lett ; 22(4): 1804-1811, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-34898226

RESUMO

Transition metal layered oxides (LiNixCoyMn1-x-yO2, NCM) have been considered as one of the most promising cathodes for lithium-ion batteries used in long-mileage electric vehicles and energy storage systems. Despite its potential interest, dissolved transition metal (TM) ions toward anode sides can catalyze parasitic reactions such as electrolytic decomposition and dendritic Li growth, ultimately leading to catastrophic safety hazards. In this study, we demonstrate that Prussian Blue (PB) nanoparticles anchored to a commercial PE separator significantly reduce cell resistance and effectively suppress TM crossover during cycling, even under harsh conditions that accelerate Ni dissolution. Therefore, using a PB-coated separator in a harsh condition to intentionally dissolve Ni2+ ions at a high cutoff potential of 4.6 V, NCM||graphite full cells maintain 50.8% of their initial capacity at the 150th cycle. Scalable production of PB-coated separator through the facile synthetic methods can help establish a new research direction for the design of high-energy-density batteries.

8.
Adv Mater ; 33(13): e2004717, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33594714

RESUMO

Harvesting of low-grade heat (<100 °C) is promising, but its application is hampered by a lack of efficient and low-cost systems. The thermally regenerative electrochemical cycle (TREC) is a potential alternative system with high energy-conversion efficiency. Here, the temperature coefficient (α), which is a key factor in a TREC, is studied by tuning the hydration entropy of the electrochemical reaction. The change of α in copper hexacyanoferrate (CuHCFe) with intercalation of different monovalent cations (Na+ , K+ , Rb+ , and Cs+ ) and a larger α value of -1.004 mV K-1 being found in the Rb+ system are observed. With a view to practical application, a full cell is constructed for low-grade heat harvesting. The resultant ηe is 4.34% when TREC operates between 10 and 50 °C, which further reaches 6.21% when 50% heat recuperation is considered. This efficiency equals to 50% of the Carnot efficiency, which is thought to be the highest ηe reported for low-grade heat harvesting systems. This study provides a fundamental understanding of the mechanisms governing the TREC, and the demonstrated efficient system paves the way for low-grade heat harvesting.

9.
Sci Rep ; 11(1): 854, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441566

RESUMO

Microbial rhodopsins are distributed through many microorganisms. Heliorhodopsins are newly discovered but have an unclear function. They have seven transmembrane helices similar to type-I and type-II rhodopsins, but they are different in that the N-terminal region of heliorhodopsin is cytoplasmic. We chose 13 representative heliorhodopsins from various microorganisms, expressed and purified with an N-terminal His tag, and measured the absorption spectra. The 13 natural variants had an absorption maximum (λmax) in the range 530-556 nm similar to proteorhodopsin (λmax = 490-525 nm). We selected several candidate residues that influence rhodopsin color-tuning based on sequence alignment and constructed mutants via site-directed mutagenesis to confirm the spectral changes. We found two important residues located near retinal chromophore that influence λmax. We also predict the 3D structure via homology-modeling of Thermoplasmatales heliorhodopsin. The results indicate that the color-tuning mechanism of type-I rhodopsin can be applied to understand the color-tuning of heliorhodopsin.

10.
J Acad Nutr Diet ; 119(11): 1842-1851.e2, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31262696

RESUMO

BACKGROUND: Fruit consumption is known to be beneficial to health. However, the health benefits of fruit juice are controversial due to its high sugar content. OBJECTIVES: To examine the associations of frequency of consumption of whole fruit and fruit juice with obesity and metabolic syndrome. DESIGN: This cross-sectional study used data from the 2012-2015 Korea National Health and Nutrition Examination Survey. PARTICIPANTS: A total of 10,460 adults (4,082 men and 6,378 women) aged 19 to 64 years were included in the study. MAIN OUTCOME MEASURES: Frequency of consumption of whole fruit and fruit juice was evaluated using a food frequency questionnaire, and dietary sugar intake was calculated using a 24-hour recall. Obesity and abdominal obesity were determined using body mass index and waist circumference, respectively. Metabolic syndrome was defined on the basis of the National Cholesterol Education Program Adult Treatment Panel III. STATISTICAL ANALYSES PERFORMED: Multiple logistic regression analysis was performed to examine the associations between frequency of whole fruit or fruit juice consumption and obesity and metabolic syndrome abnormalities. RESULTS: The percentage of participants who consumed whole fruit daily was 32.6%, whereas 52.3% consumed fruit juice rarely. The average intake of total sugars was 14.9% of total energy, which was within the recommend range (<20% of total energy) for Koreans. Consuming whole fruit ≥1 time/day was associated with reduced prevalence of obesity, abdominal obesity, and elevated blood pressure compared with consuming whole fruit ≤1 time/wk. However, frequency of fruit juice consumption showed no association with obesity, abdominal obesity, and metabolic syndrome. CONCLUSIONS: Frequency of whole fruit consumption was associated with reduced prevalence of obesity and metabolic syndrome abnormalities among Korean adults with average total sugar intake within the recommended range.


Assuntos
Dieta , Sucos de Frutas e Vegetais , Frutas , Obesidade/epidemiologia , Adulto , Estudos Transversais , Açúcares da Dieta/administração & dosagem , Ingestão de Energia , Feminino , Humanos , Masculino , Rememoração Mental , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade , Inquéritos Nutricionais , Obesidade Abdominal/epidemiologia , República da Coreia/epidemiologia , Inquéritos e Questionários
11.
J Am Chem Soc ; 141(1): 262-271, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30532962

RESUMO

The engineering of microbial rhodopsins with enhanced fluorescence is of great importance in the expanding field of optogenetics. Here we report the discovery of two mutants (W76S/Y179F and L83Q) of a sensory rhodopsin from the cyanobacterium Anabaena PCC7120 with opposite fluorescence behavior. In fact, while W76S/Y179F displays, with respect to the wild-type protein, a nearly 10-fold increase in red-light emission, the second is not emissive. Thus, the W76S/Y179F, L83Q pair offers an unprecedented opportunity for the investigation of fluorescence enhancement in microbial rhodopsins, which is pursued by combining transient absorption spectroscopy and multiconfigurational quantum chemistry. The results of such an investigation point to an isomerization-blocking electronic effect as the direct cause of instantaneous (subpicosecond) fluorescence enhancement.


Assuntos
Anabaena/metabolismo , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Engenharia de Proteínas , Rodopsinas Microbianas/química , Rodopsinas Microbianas/metabolismo , Transporte de Elétrons , Modelos Moleculares , Proteínas Mutantes/genética , Conformação Proteica , Rodopsinas Microbianas/genética , Espectrometria de Fluorescência
12.
Front Microbiol ; 9: 439, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29593685

RESUMO

Student microbial ecology laboratory courses are often conducted as condensed courses in which theory and wet lab work are combined in a very intensive short time period. In last decades, the study of marine microbial ecology is increasingly reliant on molecular-based methods, and as a result many of the research projects conducted in such courses require sequencing that is often not available on site and may take more time than a typical course allows. In this work, we describe a protocol combining molecular and functional methods for analyzing proteorhodopsins (PRs), with visible results in only 4-5 days that do not rely on sequencing. PRs were discovered in oceanic surface waters two decades ago, and have since been observed in different marine environments and diverse taxa, including the abundant alphaproteobacterial SAR11 group. PR subgroups are currently known to absorb green and blue light, and their distribution was previously explained by prevailing light conditions - green pigments at the surface and blue pigments in deeper waters, as blue light travels deeper in the water column. To detect PR in environmental samples, we created a chimeric plasmid suitable for direct expression of PRs using PCR amplification and functional analysis in Escherichia coli cells. Using this assay, we discovered several exceptional cases of PRs whose phenotypes differed from those predicted based on sequence only, including a previously undescribed yellow-light absorbing PRs. We applied this assay in two 10-days marine microbiology courses and found it to greatly enhance students' laboratory experience, enabling them to gain rapid visual feedback and colorful reward for their work. Furthermore we expect this assay to promote the use of functional assays for the discovery of new rhodopsin variants.

13.
Asian-Australas J Anim Sci ; 31(1): 40-46, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28427254

RESUMO

OBJECTIVE: To examine the effects of Rhodobacter sphaeroides (R. sphaeroides) supplementation as a direct-fed microbial (DFM) on rumen fermentation in dairy cows and on coenzyme Q10 (CoQ10) transition into milk, an in vitro rumen simulation batch culture and an in vivo dairy cow experiment were conducted. METHODS: The characteristics of in vitro ruminal fermentation were investigated using rumen fluids from six cannulated Holstein dairy cows at 2 h post-afternoon feeding. A control treatment was included in the experiments based on a typified total mixed ration (TMR) for lactating dairy cows, which was identical to the one used in the in vivo study, plus R. sphaeroides at 0.1%, 0.3%, and 0.5% TMR dry matter. The in vivo study employed six ruminally cannulated lactating Holstein cows randomly allotted to either the control TMR (C-TMR) treatment or to a diet supplemented with a 0.5% R. sphaeroides culture (S-TMR, dry matter basis) ad libitum. The presence of R. sphaeroides was verified using denaturing gradient gel electrophoresis (DGGE) applied to the bacterial samples obtained from the in vivo study. The concentration of CoQ10 in milk and in the supernatant from the in vitro study was determined using high performance liquid chromatography. RESULTS: The results of the in vitro batch culture and DGGE showed that the concentration of CoQ10 significantly increased after 2 h of R. sphaeroides supplementation above 0.1%. When supplemented to the diet of lactating cows at the level of 0.5%, R. sphaeroides did not present any adverse effect on dry matter intake and milk yield. However, the concentration of CoQ10 in milk dramatically increased, with treated cows producing 70.9% more CoQ10 than control cows. CONCLUSION: The CoQ10 concentration in milk increased via the use of a novel DFM, and R. sphaeroides might be used for producing value-added milk and dairy products in the future.

14.
ACS Nano ; 11(6): 6218-6224, 2017 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-28531350

RESUMO

We demonstrate here an embedded metal electrode for highly efficient organic-inorganic hybrid nanowire solar cells. The electrode proposed here is an effective alternative to the conventional bus and finger electrode which leads to a localized short circuit at a direct Si/metal contact and has a poor collection efficiency due to a nonoptimized electrode design. In our design, a Ag/SiO2 electrode is embedded into a Si substrate while being positioned between Si nanowire arrays underneath poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), facilitating suppressed recombination at the Si/Ag interface and notable improvements in the fabrication reproducibility. With an optimized microgrid electrode, our 1 cm2 hybrid solar cells exhibit a power conversion efficiency of up to 16.1% with an open-circuit voltage of 607 mV and a short circuit current density of 34.0 mA/cm2. This power conversion efficiency is more than twice as high as that of solar cells using a conventional electrode (8.0%). The microgrid electrode significantly minimizes the optical and electrical losses. This reproducibly yields a superior quantum efficiency of 99% at the main solar spectrum wavelength of 600 nm. In particular, our solar cells exhibit a significant increase in the fill factor of 78.3% compared to that of a conventional electrode (61.4%); this is because of the drastic reduction in the metal/contact resistance of the 1 µm-thick Ag electrode. Hence, the use of our embedded microgrid electrode in the construction of an ideal carrier collection path presents an opportunity in the development of highly efficient organic-inorganic hybrid solar cells.

15.
Anim Reprod Sci ; 170: 51-60, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27068520

RESUMO

The main objective of this study was to investigate the effects of cultured wild ginseng root extracts (cWGRE) on the sperm of boars and the reproductive system of guinea pigs. Firstly, semen collected from boars (n=10) were incubated in 38°C for 1h with xanthine and xanthine oxidase to generate ROS. The cWGRE was added to the sperm culture system to test its antioxidant effect on the boar sperm. The amount of Reactive Oxygen Species (ROS) was measured by a chemiluminescence assay using luminol. The results indicated that the addition of cWGRE to boar sperm culture inhibited xanthine and xanthine oxidase-induced ROS concentrations. Treatment with cWGRE also had a positive effect on maintaining sperm motility. Effects of cWGRE administration on vitamin C-deficient guinea pigs were further investigated. Hartley guinea pigs (n=25) at 8 weeks of age were randomly divided into five groups. With the exception of the positive control group, each group was fed vitamin C-deficient feed for 21days (d). Respective groups were also orally administered cWGRE, ginseng extract, or mixed ginsenosides for 21 days. In comparison to the control group, oral administration of cWGRE reduced (P<0.05) amount of lipid peroxidation and increased (P<0.05) both glutathione peroxidase concentrations and the trolox equivalent antioxidant capacity. In addition, administration of cWGRE induced increases (P<0.05) in body weight, testosterone concentrations, and spermatid populations. The results of the present study support our hypothesis that cWGRE has positive effects on male reproductive functions via suppression of ROS production.


Assuntos
Antioxidantes/farmacologia , Panax/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Suínos/fisiologia , Animais , Antioxidantes/química , Glutationa/metabolismo , Cobaias , Peroxidação de Lipídeos , Masculino , Extratos Vegetais/química , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermátides , Espermatogênese , Espermatozoides/fisiologia , Testosterona/sangue
16.
Biochem Biophys Res Commun ; 468(4): 606-10, 2015 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-26545776

RESUMO

Lipid homeostasis in mammalian cells is regulated by sterol regulatory element-binding protein (SREBP) transcription factors that are activated through sequential cleavage by Golgi Site-1 and Site-2 proteases. Fission yeast SREBP, Sre1, engages a different mechanism involving the Golgi Dsc E3 ligase complex, but it is not clearly understood exactly how Sre1 is proteolytically cleaved and activated. In this study, we screened the Schizosaccharomyces pombe non-essential haploid deletion collection to identify missing components of the Sre1 cleavage machinery. Our screen identified an additional component of the SREBP pathway required for Sre1 proteolysis named rhomboid protein 2 (Rbd2). We show that an rbd2 deletion mutant fails to grow under hypoxic and hypoxia-mimetic conditions due to lack of Sre1 activity and that this growth phenotype is rescued by Sre1N, a cleaved active form of Sre1. We found that the growth inhibition phenotype under low oxygen conditions is specific to the strain with deletion of rbd2, not any other fission yeast rhomboid-encoding genes. Our study also identified conserved residues of Rbd2 that are required for Sre1 proteolytic cleavage. All together, our results suggest that Rbd2 is a functional SREBP protease with conserved residues required for Sre1 cleavage and provide an important piece of the puzzle to understand the mechanisms for Sre1 activation and the regulation of various biological and pathological processes involving SREBPs.


Assuntos
Peptídeo Hidrolases/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/fisiologia , Schizosaccharomyces/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/química , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Sítios de Ligação , Proliferação de Células/fisiologia , Ativação Enzimática , Estresse Oxidativo/fisiologia , Oxigênio/metabolismo , Peptídeo Hidrolases/química , Peptídeo Hidrolases/fisiologia , Ligação Proteica , Especificidade por Substrato
17.
BMB Rep ; 48(12): 685-90, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26058396

RESUMO

The eukaryotic genome is packed into chromatin, which is important for the genomic integrity and gene regulation. Chromatin structures are maintained through assembly and disassembly of nucleosomes catalyzed by histone chaperones. Asf1 (anti-silencing function 1) is a highly conserved histone chaperone that mediates histone transfer on/off DNA and promotes histone H3 lysine 56 acetylation at globular core domain of histone H3. To elucidate the role of Asf1 in the modulation of chromatin structure, we screened and identified small molecules that inhibit Asf1 and H3K56 acetylation without affecting other histone modification. These pyrimidine-2,4,6-trione derivative molecules inhibited the nucleosome assembly mediated by Asf1 in vitro, and reduced the H3K56 acetylation in HeLa cells. Furthermore, production of HSV viral particles was reduced by these compounds. As Asf1 is implicated in genome integrity, cell proliferation, and cancer, current Asf1 inhibitor molecules may offer an opportunity for the therapeutic development for treatment of diseases.


Assuntos
Proteínas de Ciclo Celular/antagonistas & inibidores , Cromatina/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Acetilação , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Histonas/metabolismo , Humanos , Chaperonas Moleculares , Nucleossomos/efeitos dos fármacos , Nucleossomos/metabolismo
18.
Otolaryngol Head Neck Surg ; 143(6): 837-42, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21109087

RESUMO

OBJECTIVE: It is not known how many olfactory receptor neurons should be intact to maintain olfaction in mouse models treated with 3-methylindole. The aim of this study is to investigate the relationship between a simple olfactory test outcome and the olfactory neuronal population. STUDY DESIGN: Mouse model. SETTING: Animal laboratory of the Seoul National University Bundang Hospital. SUBJECTS AND METHODS: Olfactory dysfunction was induced by intraperitoneal injection of 3-methylindole in 38 six-week-old female C57BL6 mice. Olfactory function was evaluated by a food-finding test following 72-hour starvation. The olfactory neuronal population was quantified by olfactory marker protein (OMP) expression. RESULTS: The average time for finding food was 8.1 seconds in control mice. It was 13.4, 84.4, 90.1, and 111.4 seconds for mice injected with 100, 200, 300, and 400 µg/g of 3-methylindole, respectively. Harvesting the whole olfactory neuroepithelium, densitometric analysis showed significant decrease of OMP in the 300- and 400-µg/g groups as compared with controls (18.8% and 17.5% of relative density, respectively). In the olfactory bulb, there was a significant decrease of OMP in the 200-, 300-, and 400-µg/g groups (44.5%, 37.0%, and 9.0% of relative density, respectively). The food-finding time had a significant reverse correlation with the relative density of OMP both in the olfactory bulb and in the olfactory neuroepithelium. CONCLUSION: Our study showed that olfactory impairment was correlated with olfactory neuronal population in mice treated with 3-methylindole. The food-finding test would be a useful tool that could be easily performed without special training in the 3-methylindole-treated C57BL6 anosmic mouse model.


Assuntos
Noxas/efeitos adversos , Transtornos do Olfato/induzido quimicamente , Neurônios Receptores Olfatórios/efeitos dos fármacos , Escatol/efeitos adversos , Olfato/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Feminino , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos C57BL , Noxas/administração & dosagem , Proteína de Marcador Olfatório/biossíntese , Escatol/administração & dosagem
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