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1.
PLoS One ; 19(2): e0298691, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38408110

RESUMO

This study investigated the leftover rate of side dishes in school lunches provided by communal kitchens in Japan's Chugoku region, with a focus on vegetable dishes supplied in containers and three types of menu items served daily to 20 elementary and junior high schools in communal kitchen A for 116 days. First, the leftovers in the containers that were returned to the communal kitchen were weighed and combined. The study then compared outside temperature, distance from communal kitchen A, school type, number of students per class, assignment of nutrition teachers, and time elapsed after cooking. Finally, we examined the relationship between these factors and the leftover rate using multiple regression analysis. The median leftover rate was 20.1% (0-96.9) for 250 side dishes with a high leftover rate; however, this was widely distributed. The number of students per class, assignment of nutrition teachers, and time elapsed after cooking were strongly related to the leftover rate; the adjusted coefficient of determination, R2, was 0.236. The regression results indicated that regarding the side dish leftover rate, the standardized coefficient, ß, was 0.414, 0.215, 0.107, 0.093, and 0.094 for the number of students per class, assignment of nutrition teacher, the time elapsed after the end of cooking, distance from communal kitchen A, and presence of seaweed, respectively (p<0.001). Dietary education by homeroom and nutrition teachers and reducing the time elapsed after cooking impacts students' awareness and preferences, which may decrease the leftover rate.


Assuntos
Dieta , Verduras , Humanos , Japão , Culinária , Instituições Acadêmicas
2.
Angew Chem Int Ed Engl ; 62(47): e202310976, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37650440

RESUMO

For the application of CO2 as an energy storage material, a H2 storage system has been proposed based on the interconversion of CO2 and formic acid (or formate). However, energy losses are inevitable in the conversion of electrical energy to H2 as chemical energy (≈70 % electrical efficiency) and H2 to electrical energy (≈40 % electrical efficiency). To overcome these significant energy losses, we developed a system based on the interconversion of CO2 and formate for the direct storage and generation of electricity. In this paper, we report an aqueous redox flow battery system using homogeneous Ir catalysts with CO2 -formate redox pair. The system exhibited a maximum discharge capacity of 10.5 mAh (1.5 Ah L-1 ), capacity decay of 0.2 % per cycle, and total turnover number of 2550 after 50 cycles. During charging-discharging, in situ fluorescence X-ray absorption fine structure spectroscopy based on an online setup indicated that the active species was in a high valence state of IrIV .

3.
J Colloid Interface Sci ; 641: 348-358, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36940591

RESUMO

HYPOTHESES: Bicontinuous microemulsions (BMEs) have attracted attention as unique heterogeneous mixture for electrochemistry. An interface between two immiscible electrolyte solutions (ITIES) is an electrochemical system that straddles the interface between a saline and an organic solvent with a lipophilic electrolyte. Although most BMEs have been reported with nonpolar oils, such as toluene and fatty acids, it should be possible to construct a sponge-like three-dimensionally expanded ITIES comprising a BME phase. EXPERIMENTS: Dichloromethane (DCM)-water microemulsions stabilized by a surfactant were investigated in terms of the concentrations of co-surfactants and hydrophilic/lipophilic salts. A Winsor III microemulsion three-layer system, consisting of an upper saline phase, a middle BME phase, and a lower DCM phase, was prepared, and electrochemistry was conducted in each phase. FINDINGS: We found the conditions for ITIES-BME phases. Regardless of where the three electrodes were placed in the macroscopically heterogeneous three-layer system, electrochemistry was possible, as in a homogeneous electrolyte solution. This indicates that the anodic and cathodic reactions can be divided into two immiscible solution phases. A redox flow battery comprising a three-layer system with a BME as the middle phase was demonstrated, paving the way for applications such as electrolysis synthesis and secondary batteries.

4.
Odontology ; 111(2): 428-438, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36214897

RESUMO

Smoking is a risk factor for periodontitis, and the immune response of periodontal tissues in patients with periodontitis may be strongly affected by smoking. The purpose of this study was to elucidate the bioactivity and signal transduction of human gingival endothelial cells (HGECs) due to nicotinic stimulation using a cultured medium supplemented with lipopolysaccharide (LPS) as a model of periodontitis. HGECs were cultured in medium supplemented with LPS, nicotine, nicotine + LPS, and medium supplemented without nicotine or LPS (control). Cell proliferation was assessed using Alamar blue. Cytotoxicity was assessed by lactate dehydrogenase leakage. The expression of adhesion molecule-1 (ICAM-1, VCAM-1) was assessed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay. The expression of nicotinic acetylcholine receptor (nAChR) subunits (α3, α5, α7, ß2 and ß4) was evaluated by RT-PCR. The involvement of p38 mitogen-activated protein kinase (p38MAPK) and protein kinase C (PKC) cell signaling pathways in ICAM-1 and VCAM-1 expression was investigated by RT-qPCR with specific inhibitors. HGECs stimulated with LPS, nicotine and nicotine + LPS showed inhibition of cell proliferation, increase of cell death, and increase of gene and protein expression of ICAM-1. Moreover, HGECs showed the presence of α5 and α7 nAChR subunits. The expression of ICAM-1 in HGECs stimulated with LPS, nicotine, and nicotine + LPS was significantly suppressed by p38MAPK inhibitor, but not by a PKC inhibitor. The nAChR subunits of HGECs are α5 and α7, and that HGECs stimulated with nicotine and LPS express ICAM-1 via p38MAPK pathway.


Assuntos
Nicotina , Receptores Nicotínicos , Humanos , Nicotina/farmacologia , Lipopolissacarídeos/farmacologia , Molécula 1 de Adesão Intercelular/metabolismo , Células Endoteliais/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo
5.
Chem Asian J ; 18(1): e202201047, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36398386

RESUMO

We performed X-ray absorption studies for the electrolytes of a Ti-Mn redox flow battery (RFB) to understand the redox reaction of the Ti/Mn ions and formation of precipitates in charged catholyte, because suppression of the disproportionation reaction is a key to improve the cyclability of Ti-Mn RFB and enhance the energy density. Hard X-ray absorption spectroscopy with a high transmittance and soft X-ray absorption spectroscopy to directly observe the 3d orbitals were complementarily employed. Moreover, the Ti/Mn 3d electronic structure for each precipitate and solution in the charged catholyte was investigated by using scanning transmission X-ray microscopy: the valence of Mn in the precipitate is mostly attributed to 4+, and the solution includes only Mn2+ . This charge disproportionation reaction should occur after the Mn ions in the catholyte should be oxidized from Mn2+ to Mn3+ by charge.


Assuntos
Eletrólitos , Titânio , Espectroscopia por Absorção de Raios X , Oxirredução
6.
Rev. Nutr. (Online) ; 35: e210230, 2022. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1394679

RESUMO

ABSTRACT Objective Characterize and comparatively analyse the organization of nutritional attention to prenatal care, the puerperium period and breastfeeding, in primary health care, in two municipalities of Baixada Santista, São Paulo, Brazil. Methods This was an exploratory-analytical study of family health units and the mixed basic care units of Cubatão (n=17) and Guarujá (n=14). For this purpose, seven domains of the Nutritional Attention Assessment Instrument in Primary Health Care were used. Descriptive analysis and the Mann-Whitney and Pearson's chi-square tests were performed. Results In the comparison between the municipalities, the best scores were obtained in Guarujá. Statistically significant differences were found for the following indicators: support for nutritional attention actions: infrastructure and permanent education (<0.001); food and nutritional surveillance (<0.001); nutritional attention focused on prenatal care (<0.001); and nutritional attention focused on postpartum care and breastfeeding (0.012). Nutritional attention actions for mother-infant groups were more frequent in the city of Guarujá, which compared with Cubatão, achieved better scores for the nutritional attention evaluation indicators. Conclusion The municipality of Guarujá had better indicators of infrastructure and permanent education, food and nutrition surveillance, and puerperal and breastfeeding nutritional care. However, weaknesses persist in the organization of nutritional care in the two cities studied, especially regarding the work process.


RESUMO Objetivo Caracterizar e analisar comparativamente a organização da Atenção Nutricional ao pré-natal, ao puerpério e ao aleitamento, na Atenção Primária à Saúde, em dois municípios da Baixada Santista, São Paulo, Brasil. Métodos Realizou-se estudo exploratório-analítico das Unidades de Saúde da Família e Unidades Básicas de Saúde mistas de Cubatão (n=17) e Guarujá (n=14). Para tanto, foram utilizados sete domínios do Instrumento de Avaliação da Organização da Atenção Nutricional na Atenção Primária à Saúde, validado em seu conteúdo. Realizaram-se análise descritiva e os testes de Mann-Whitney e o Qui-quadrado de Pearson. Resultados Na comparação entre os municípios, as melhores pontuações foram obtidas em Guarujá. Encontraram-se diferenças estatisticamente significantes para os respectivos indicadores, Apoio às ações de Atenção Nutricional: Infraestrutura e Educação Permanente (<0,001); Vigilância Alimentar e Nutricional (<0,001); Atenção Nutricional ao Pré-Natal (<0,001); e a Atenção Nutricional ao Puerpério e ao Aleitamento (0,012). As ações de Atenção Nutricional ao grupo maternoinfantil foram mais frequentes no município de Guarujá, alcançando melhores pontuações dos indicadores de avaliação da Atenção Nutricional, comparativamente aos alcançados por Cubatão. Conclusão O município de Guarujá apresentou melhores indicadores de infraestrutura e educação permanente, vigilância alimentar e nutricional e atenção nutricional puerperal e ao aleitamento. Entretanto, persistem fragilidades na organização da Atenção Nutricional nos dois municípios estudados, principalmente quanto ao processo de trabalho.


Assuntos
Humanos , Masculino , Feminino , Adulto , Adulto Jovem , Cuidado Pós-Natal , Cuidado Pré-Natal , Atenção Primária à Saúde/organização & administração , Política Nutricional , Brasil/etnologia , Centros de Saúde , Estudos Transversais , Cidades
7.
JA Clin Rep ; 7(1): 6, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33404797

RESUMO

BACKGROUND: Conjoined twins are an extremely rare congenital occurrence, and anesthetic management for surgical separation presents unique challenges for anesthesiologists. CASE PRESENTATION: Five-month-old male pygopagus conjoined twins underwent separation surgery. We performed anesthesia induction in the supine position and surgery in the prone position. This presented a challenge because the transition from supine to prone position reversed the positional relationship between the two babies, resulting in crossing of the respiratory circuits and monitors. To solve the problem, we used anesthesia machines and monitors on the opposite side of each baby during anesthesia induction. The positional relationship between the twins and anesthesia machines and monitors normalized after the change to the prone position. Following the separation surgery, the twins were discharged without any complications. CONCLUSIONS: Our method of using opposite side anesthetic machines and monitors for anesthesia induction was useful for the safe anesthetic management of pygopagus conjoined twins.

8.
Talanta ; 221: 121666, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33076173

RESUMO

Anthropogenic CO2 emissions are contributing to global warming and ocean acidification. Rapid and accurate measurements of seawater carbonate chemistry are critical to understand current changes in the ocean and to predict future effects of such changes on marine organisms and ecosystems. Total alkalinity (AT) measurements can be used to directly determine the calcification rate, but they are time-consuming and require large sample volumes. Herein, we describe an automated and transportable flow-through system that can conduct continuous AT measurement using an ion sensitive field effect transistor (ISFET) - Ag/AgCl sensor and three different reference materials. The response time, stability, and uncertainty of our system were evaluated by comparing AT values of calibrated reference materials to those calculated by our system. Our system requires only small amounts of seawater (<10 mL) and a short time per sample (<5 min) to produce results with a relative uncertainty of less than 0.1% (approx. 2.2 µmol kg-1). This system is expected to facilitate easy and rapid in-situ measurement of AT. Continuous AT measurements would enable us to determine short-term calcification responses to changes in light or temperature and improve our understanding of the metabolic mechanisms of creatures such as corals.

9.
Comput Struct Biotechnol J ; 18: 1352-1362, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612758

RESUMO

Engineering enzyme catalytic properties is important for basic research as well as for biotechnological applications. We have previously shown that the reshaping of enzyme access tunnels via the deletion of a short surface loop element may yield a haloalkane dehalogenase variant with markedly modified substrate specificity and enantioselectivity. Here, we conversely probed the effects of surface loop-helix transplantation from one enzyme to another within the enzyme family of haloalkane dehalogenases. Precisely, we transplanted a nine-residue long extension of L9 loop and α4 helix from DbjA into the corresponding site of DbeA. Biophysical characterization showed that this fragment transplantation did not affect the overall protein fold or oligomeric state, but lowered protein stability (ΔT m = -5 to 6 °C). Interestingly, the crystal structure of DbeA mutant revealed the unique structural features of enzyme access tunnels, which are known determinants of catalytic properties for this enzyme family. Biochemical data confirmed that insertion increased activity of DbeA with various halogenated substrates and altered its enantioselectivity with several linear ß-bromoalkanes. Our findings support a protein engineering strategy employing surface loop-helix transplantation for construction of novel protein catalysts with modified catalytic properties.

10.
Nat Commun ; 9(1): 3103, 2018 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-30082790

RESUMO

The HIRA histone chaperone complex deposits the histone variant H3.3 onto chromatin in a DNA synthesis-independent manner. It comprises three identified subunits, HIRA, UBN1 and CABIN1, however the functional oligomerization state of the complex has not been investigated. Here we use biochemical and crystallographic analysis to show that the HIRA subunit forms a stable homotrimer that binds two subunits of CABIN1 in vitro. A HIRA mutant that is defective in homotrimer formation interacts less efficiently with CABIN1, is not enriched at DNA damage sites upon UV irradiation and cannot rescue new H3.3 deposition in HIRA knockout cells. The structural homology with the homotrimeric replisome component Ctf4/AND-1 enables the drawing of parallels and discussion of the functional importance of the homotrimerization state of the HIRA subunit.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas de Ciclo Celular/química , DNA/química , Chaperonas de Histonas/química , Histonas/química , Chaperonas Moleculares/química , Proteínas Nucleares/química , Fatores de Transcrição/química , Sítios de Ligação , Linhagem Celular Tumoral , Cromatina/química , Cristalografia por Raios X , Dano ao DNA , Bases de Dados de Proteínas , Proteínas de Fluorescência Verde/química , Células HeLa , Humanos , Plasmídeos , Ligação Proteica , Conformação Proteica , Raios Ultravioleta
11.
FEBS J ; 285(8): 1540-1555, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29505698

RESUMO

Enzymes belonging to the aspartase/fumarase superfamily catalyze elimination of various functional groups from succinate derivatives and play an important role in primary metabolism and aromatic compound degradation. Recently, an aspartase/fumarase superfamily enzyme, CreD, was discovered in cremeomycin biosynthesis. This enzyme catalyzes the elimination of nitrous acid from nitrosuccinate synthesized from aspartate by CreE, a flavin-dependent monooxygenase. Nitrous acid generated by this pathway is an important precursor of the diazo group of cremeomycin. CreD is the first aspartase/fumarase superfamily enzyme that was reported to catalyze the elimination of nitrous acid, and therefore we aimed to analyze its reaction mechanism. The crystal structure of CreD was determined by the molecular replacement native-single anomalous diffraction method at 2.18 Å resolution. Subsequently, the CreD-fumarate complex structure was determined at 2.30 Å resolution by the soaking method. Similar to other aspartase/fumarase superfamily enzymes, the crystal structure of CreD was composed of three domains and formed a tetramer. Two molecules of fumarate were observed in one subunit of the CreD-fumarate complex. One of them was located in the active site pocket formed by three different subunits. Intriguingly, no histidine residue, which usually functions as a catalytic acid in aspartase/fumarase superfamily enzymes, was found around the fumarate molecule in the active site. Based on the mutational analysis, we propose a catalytic mechanism of CreD, in which Arg325 acts as a catalytic acid. DATABASES: The crystal structures of CreD and the CreD-fumarate complex were deposited to PDB under the accession numbers 5XNY and 5XNZ, respectively. ENZYMES: Nitrosuccinate lyase CreD, EC4.3.


Assuntos
Proteínas de Bactérias/metabolismo , Liases/metabolismo , Ácido Nitroso/metabolismo , Ácido Succínico/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/classificação , Proteínas de Bactérias/genética , Biocatálise , Domínio Catalítico , Cristalografia por Raios X , Liases/química , Liases/genética , Modelos Moleculares , Estrutura Molecular , Ácido Nitroso/química , Filogenia , Domínios Proteicos , Homologia de Sequência de Aminoácidos , Streptomyces/genética , Streptomyces/metabolismo , Especificidade por Substrato , Ácido Succínico/química
12.
Acta Crystallogr F Struct Biol Commun ; 72(Pt 12): 897-902, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27917838

RESUMO

A tetrahydrofolate-dependent O-demethylase, LigM, from Sphingobium sp. SYK-6 was crystallized by the hanging-drop vapour-diffusion method. However, the obtained P3121 or P3221 crystals, which diffracted to 2.5-3.3 Šresolution, were hemihedrally twinned. To overcome the twinning problem, microseeding using P3121/P3221 crystals as microseeds was performed with optimization of the reservoir conditions. As a result, another crystal form was obtained. The newly obtained crystal diffracted to 2.5-3.0 Šresolution and belonged to space group P21212, with unit-cell parameters a = 102.0, b = 117.3, c = 128.1 Å. The P21212 crystals diffracted to better than 2.0 Šresolution after optimizing the cryoconditions. Phasing using the single anomalous diffraction method was successful at 3.0 Šresolution with a Pt-derivative crystal. This experience suggested that microseeding is an effective method to overcome the twinning problem, even when twinned crystals are utilized as microseeds.


Assuntos
Proteínas de Bactérias/química , Oxirredutases O-Desmetilantes/química , Sphingomonadaceae/química , Tetra-Hidrofolatos/química , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Cristalização , Cristalografia por Raios X , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Oxirredutases O-Desmetilantes/genética , Oxirredutases O-Desmetilantes/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sphingomonadaceae/enzimologia , Tetra-Hidrofolatos/metabolismo , Difração de Raios X
13.
Carbohydr Res ; 434: 121-131, 2016 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-27639338

RESUMO

A regio- and stereo-controlled, rhodium(II)-catalyzed amidoglycosylation of alcohols has been developed using O-acetylated glycals, trichloroethoxysulfonamide, and iodosobenzene. This one-pot amidoglycosylation was applied to a variety of primary and secondary alcohols to afford the ß-O-glycosides with acceptable yields up to 84%. The reaction would proceed via stereoselective intermolecular aziridination of the glycal from the α-face followed by SN2 reaction with alcohol at C-1 from the ß-face to give 1,2:2,3-di-trans-substituted isomer only.


Assuntos
Álcoois/síntese química , Amidas/química , Sulfonamidas/química , Álcoois/química , Glicosilação , Iodobenzenos/química , Estrutura Molecular , Ródio/química , Estereoisomerismo
14.
Rinsho Byori ; 64(1): 80-4, 2016 Jan.
Artigo em Japonês | MEDLINE | ID: mdl-27192802

RESUMO

As a response to the health effects associated with the Fukushima Daiichi Nuclear Power Plant accident that occurred after the Great East Japan Earthquake, the Thyroid Ultrasound Examination program as a part of the Fukushima Health Management Survey was started on Oct. 9th, 2011. Since this project required a large-scale cohort comprising all residents aged ≤ 18 years living in Fukushima when the earthquake happened, the nurturing of many ultrasound examiners was a matter of great urgency. Moreover, the standardization of examination procedures and skills of examiners were also important issues. Therefore, educational projects were established to develop ultrasound skills for medical doctors and technicians in Fukushima Prefecture. Marked efforts for this project resulted in increases in ultrasound examiners and institutions taking part in the Thyroid Ultrasound Examination project. Medical technicians specialized in ultrasound examinations are actively involved in these educational projects. We report the details of human resource development projects from the point of view of such medical technicians.


Assuntos
Acidente Nuclear de Fukushima , Glândula Tireoide/diagnóstico por imagem , Inquéritos Epidemiológicos , Humanos , Tecnologia Radiológica , Ultrassonografia
15.
Asian-Australas J Anim Sci ; 29(4): 523-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26949953

RESUMO

An isotope dilution method using [U-(13)C]glucose and [1-(13)C]leucine (Leu) was conducted to evaluate the effects of rice straw supplemented with urea and molasses (RSUM-diet) on plasma glucose and Leu turnover rates in sheep. Nitrogen (N) balance, rumen fermentation characteristics and blood metabolite concentrations were also determined. Four sheep were fed either mixed hay (MH-diet), or a RSUM-diet with a crossover design for two 21 days period. Feed allowance was computed on the basis of metabolizable energy at maintenance level. The isotope dilution method was performed as the primed-continuous infusion on day 21 of each dietary period. Nitrogen intake was lower (p = 0.01) for the RSUM-diet and N digestibility did not differ (p = 0.57) between diets. Concentrations of rumen total volatile fatty acids tended to be higher (p = 0.09) for the RSUM-diet than the MH-diet. Acetate concentration in the rumen did not differ (p = 0.38) between diets, whereas propionate concentration was higher (p = 0.01) for the RSUM-diet compared to the MH-diet. Turnover rates as well as concentrations of plasma glucose and Leu did not differ between diets. It can be concluded that kinetics of plasma glucose and Leu metabolism were comparable between the RSUM-diet and the MH-diet, and rumen fermentation characteristics were improved in sheep fed the RSUM-diet compared to the MH-diet.

16.
Sci Rep ; 5: 10655, 2015 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-25990947

RESUMO

In the era of synthetic biology, techniques for rapidly constructing a designer long DNA from short DNA fragments are desired. To realize this, we attempted to establish a method for one-step DNA assembly of unprecedentedly large numbers of fragments. The basic technology is the Ordered Gene Assembly in Bacillus subtilis (OGAB) method, which uses the plasmid transformation system of B. subtilis. Since this method doesn't require circular ligation products but needs tandem repeat ligation products, the degree of deviation in the molar concentration of the material DNAs is the only determinant that affects the efficiency of DNA assembly. The strict standardization of the size of plasmids that clone the DNA block and the measurement of the block in the state of intact plasmid improve the reliability of this step, with the coefficient of variation of the molar concentrations becoming 7%. By coupling this method with the OGAB method, one-step assembly of more than 50 DNA fragments becomes feasible.


Assuntos
Bacillus subtilis/genética , DNA Bacteriano/biossíntese , Biologia Sintética/métodos , Sequências de Repetição em Tandem/genética , Bacteriófago lambda/genética , Fragmentação do DNA , DNA Bacteriano/genética , Plasmídeos/genética , Transformação Genética
17.
Acta Crystallogr D Biol Crystallogr ; 70(Pt 7): 1884-97, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25004965

RESUMO

The crystal structure of the novel haloalkane dehalogenase DbeA from Bradyrhizobium elkanii USDA94 revealed the presence of two chloride ions buried in the protein interior. The first halide-binding site is involved in substrate binding and is present in all structurally characterized haloalkane dehalogenases. The second halide-binding site is unique to DbeA. To elucidate the role of the second halide-binding site in enzyme functionality, a two-point mutant lacking this site was constructed and characterized. These substitutions resulted in a shift in the substrate-specificity class and were accompanied by a decrease in enzyme activity, stability and the elimination of substrate inhibition. The changes in enzyme catalytic activity were attributed to deceleration of the rate-limiting hydrolytic step mediated by the lower basicity of the catalytic histidine.


Assuntos
Halogênios/metabolismo , Hidrolases/metabolismo , Sítios de Ligação , Cristalização , Hidrolases/química , Cinética , Análise de Componente Principal
18.
J Toxicol Sci ; 39(3): 447-52, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24849679

RESUMO

Air purifiers, which release positive and negative ions generated by an electric discharge into the air, have been widely used in common households. In this study, the developmental toxicity potential of the ionized air containing positive and negative ions was evaluated in SD rats [Crl:CD(SD)] following whole-body inhalation to obtain preliminary information for the definitive study. Two groups of 10 pregnant female rats were exposed to the ionized air at concentrations of 0 and 7,000,000 ions/cm(3) for 6 hr per day from Days 6 to 19 of gestation. All dams underwent a cesarean section on Day 20 of gestation and their fetuses were examined externally, viscerally, and skeletally for morphological changes. The ionized air had no effects on dams in terms of clinical signs, body weight, food consumption, gravid uterine weights, corrected body weight by gravid uterine weight, or necropsy findings. In addition, there were no effects on the maintenance of pregnancy, including abortion or premature delivery. No exposure-related changes were detected in the number of corpora lutea, implantations, dead embryos, or live fetuses, implantation loss, live fetal weights, sex ratio, or placental weight or features. Fetal examination revealed no external, visceral, or skeletal anomalies or variations caused by the ionized air, nor were there any changes in degree of ossification. Although this study did not fully adhere to the current guidelines because of a smaller number of animals per group, it was suggested that the ionized air has no maternal toxicity or embryo-fetal toxicity in rats.


Assuntos
Filtros de Ar/efeitos adversos , Ionização do Ar , Desenvolvimento Fetal/fisiologia , Animais , Feminino , Inalação/fisiologia , Masculino , Troca Materno-Fetal/fisiologia , Gravidez , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
19.
Genes Cells ; 17(7): 597-610, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22686249

RESUMO

Agrobacterium strains containing a Ti plasmid can transfer T-DNA not only to plants but also to fungi, including the yeast Saccharomyces cerevisiae. However, no Agrobacterium strain harboring an Ri plasmid has been evaluated in fungal transformation. Some Ri plasmids have GALLS , instead of virE1 and virE2. GALLS protein can functionally substitute in plant transformation for a structurally different protein VirE2. In this study, we compared the yeast transformation ability among Agrobacterium donors: a strain containing a Ti plasmid, strains harboring either an agropine-type or a mikimopine-type Ri plasmid, and a strain having a modified Ri plasmid supplemented with a Ti plasmid type virE operon. Agrobacterium strains possessing GALLS transformed yeast cells far less efficiently than the strain containing virE operon. Production of GALLS in recipient yeast cells improved the yeast transformation mediated by an Agrobacterium strain lacking neither GALLS nor virE operon. A reporter assay to detect mobilization of the proteins fused with Cre recombinase revealed that VirE2 protein is much more abundant in yeast cells than GALLS. Based on these results, we concluded that the low yeast transformability mediated by Agrobacterium strains having the Ri plasmid is because of low amount of mobilized GALLS in yeast cells.


Assuntos
Agrobacterium/genética , Agrobacterium/metabolismo , Proteínas de Bactérias/genética , Plasmídeos/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Transformação Genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Ordem dos Genes , Óperon/genética , Mutação Puntual , Regiões Promotoras Genéticas , Transporte Proteico
20.
FEMS Microbiol Lett ; 327(2): 110-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22098388

RESUMO

The mycotoxin deoxynivalenol (DON), a secondary metabolite produced by species of the plant pathogen Fusarium, causes serious problems in cereal crop production because of its toxicity towards humans and livestock. A biological approach for the degradation of DON using a DON-degrading bacterium (DDB) appears to be promising, although information about DDBs is limited. We isolated 13 aerobic DDBs from a variety of environmental samples, including field soils and wheat leaves. Of these 13 strains, nine belonged to the Gram-positive genus Nocardioides and other four to the Gram-negative genus Devosia. The degradation phenotypes of the two Gram types were clearly different; all washed cells of the 13 strains degraded 100 µg mL(-1) DON to below the detection limit (0.5 µg mL(-1)), but the conditions inducing the DON-degrading activities differed between the two Gram types. The HPLC profiles of the DON metabolites were also distinct between the two genera, although all strains produced 3-epi-deoxynivalenol. The Gram-positive strains showed DON assimilation in media containing DON as a carbon source, whereas the Gram-negatives did not. Our results suggest that aerobic DDBs are distributed within at least two phylogenetically restricted genera, suggesting independent evolution of the DON-degradation mechanisms.


Assuntos
Bactérias/classificação , Bactérias/metabolismo , Micotoxinas/metabolismo , Tricotecenos/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Fusarium/metabolismo , Dados de Sequência Molecular , Filogenia , Microbiologia do Solo , Triticum/microbiologia
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