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1.
Proc Natl Acad Sci U S A ; 121(12): e2315707121, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38489388

RESUMO

KCTD10 belongs to the KCTD (potassiumchannel tetramerization domain) family, many members of which are associated with neuropsychiatric disorders. However, the biological function underlying the association with brain disorders remains to be explored. Here, we reveal that Kctd10 is highly expressed in neuronal progenitors and layer V neurons throughout brain development. Kctd10 deficiency triggers abnormal proliferation and differentiation of neuronal progenitors, reduced deep-layer (especially layer V) neurons, increased upper-layer neurons, and lowered brain size. Mechanistically, we screened and identified a unique KCTD10-interacting protein, KCTD13, associated with neurodevelopmental disorders. KCTD10 mediated the ubiquitination-dependent degradation of KCTD13 and KCTD10 ablation resulted in a considerable increase of KCTD13 expression in the developing cortex. KCTD13 overexpression in neuronal progenitors led to reduced proliferation and abnormal cell distribution, mirroring KCTD10 deficiency. Notably, mice with brain-specific Kctd10 knockout exhibited obvious motor deficits. This study uncovers the physiological function of KCTD10 and provides unique insights into the pathogenesis of neurodevelopmental disorders.


Assuntos
Encefalopatias , Transtornos do Neurodesenvolvimento , Canais de Potássio de Abertura Dependente da Tensão da Membrana , Animais , Camundongos , Proteínas/metabolismo , Encéfalo/metabolismo , Neurônios/metabolismo , Transtornos do Neurodesenvolvimento/genética , Encefalopatias/genética , Neurogênese/genética , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo
2.
J Environ Manage ; 356: 120592, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38508009

RESUMO

Chicken manure (CM) can pose a serious threat to environmental and human health, and need to be managed properly. The compost can effectively treat CM. However, there is limited research on the heavy metals and antibiotic resistance genes (ARGs) during compost CM. In this study, the combined application of reactor and static composting (RSC) was used to produce organic fertilizer of CM (OCM), and heavy metals, ARGs and bacterial community structure was investigated. The results show that RSC could be used to produce OCM, and OCM meet the National organic fertilizer standard (NY/T525-2021). Compared to the initial CM, DTPA-Cu, DTPA-Zn, DTPA-Pb, DTPA-Cr, DTPA-Ni and DTPA-As in OCM decreased by 40.83%, 23.73%, 34.27%, 38.62%, 16.26%, and 43.35%, respectively. RSC decreased the relative abundance of ARGs in CM by 84.06%, while the relative abundance of sul1 and ermC increased. In addition, the relative abundance and diversity of ARGs were mainly influenced by the bacterial community, with Actinobacteria, Firmicutes, and Proteobacteria becoming the dominant phyla during composting, and probably being the main carriers and dispersers of most of the ARGs. Network analyses confirmed that Gracilibacillus, Lactobacillus, Nocardiopsis, Mesorhizobium and Salinicoccus were the main potential hosts of ARGs, with the main potential hosts of sul1 and ermC being Mesorhizobium and Salinicoccus. The passivation and physicochemical properties of heavy metals contribute to the removal of ARGs, with sul1 and ermC being affected by the toal heavy metals. Application of RSC allows CM to produce mature, safe organic fertilizer after 32 d and reduces the risk of rebound from ARGs, but the issues of sul1 and ermC gene removal cannot be ignored.


Assuntos
Compostagem , Metais Pesados , Animais , Humanos , Genes Bacterianos , Esterco/análise , Galinhas , Antibacterianos/farmacologia , Fertilizantes , Resistência Microbiana a Medicamentos/genética , Bactérias/genética , Metais Pesados/análise , Ácido Pentético
3.
Chem Pharm Bull (Tokyo) ; 71(7): 528-533, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37100609

RESUMO

The efficiency of pharmacotherapy is significantly influenced by the crystal habit and polymorphic form of the drugs. Especially due to the anisotropy of different facets in crystalline material, crystal habit impacts the physicochemical properties and behaviors of a drug, which has been rarely reported. This paper describes a facile method for online monitoring of crystal plane orientation of favipiravir (T-705) by Raman spectroscopy. Firstly, we investigated the synergy of multiple physicochemical fields (solvation, agitated flow fields, etc.), and then prepared favipiravir crystals with different orientations in a controllable manner. Secondly, to establish the connection between crystal planes and Raman spectra, the favipiravir crystals were theoretically analyzed at the molecular and structural levels using density functional theory (DFT) and three dimensional (3D) visualization tools. Finally, we based on standard samples and applied it to 12 actual samples to evaluate the crystal habit of favipiravir. The results are similar to the classical X-ray diffraction (XRD) method. Additionally, the XRD method is difficult to be monitored online, while the Raman method is non-contact, fast, and requires no sample preparation, showing a great application prospect in the pharmaceutical process.


Assuntos
Amidas , Análise Espectral Raman , Análise Espectral Raman/métodos , Difração de Raios X
4.
Int J Biometeorol ; 65(2): 235-246, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33118114

RESUMO

This study was conducted to assess the link of miRNA expressions in cow's mammary gland undergoing heat stress. Twelve Holstein cows were allocated either to undergo heat stress (HS) or remain in a thermoneutral environment (non-heat stress, NS), respectively. The experiment with HS cows was carried out in August, and the experiment with NS cows was done in November. After a month, three cows from each group were slaughtered, and mammary gland samples were obtained, and then miRNA were extracted from the samples for later sequencing. From the miRNA-seq, we obtained a total of 124 differentially expressed miRNAs in HS and NS cows' mammary gland. The differentially expressed miRNA could be predicted to influence multiple target genes. The target interleukin-1 (IL-1), which play a role in regulating the function of mammary gland in dairy cows, could be affected by bta-let-7c, bta-let-7e, bta-miR-181d, bta-miR-452, and bta-miR-31. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that mitogen-activated protein kinase (MAPK) pathway plays an important role in the mammary glands of dairy cows and bta-miR-25 and bta-miR-382 may influence MAPK pathway through c-Jun N-terminal kinase (JNK) gene to affect the function of mammary gland in HS cows. In conclusion, this study characterized expression profile of miRNAs in the Holstein cows' mammary gland under summer heat stress or not. We observed miRNA expression during heat stress, which was significantly different from non-heat stress states. A comprehensive analysis of the miRNA's expression will be helpful to further study the link of miRNAs with mechanisms regulating heat stress in the cow mammary gland.


Assuntos
Transtornos de Estresse por Calor , MicroRNAs , Animais , Bovinos/genética , Feminino , Perfilação da Expressão Gênica , Transtornos de Estresse por Calor/genética , Transtornos de Estresse por Calor/veterinária , Resposta ao Choque Térmico/genética , MicroRNAs/genética , Estações do Ano
5.
Chemphyschem ; 20(4): 627-635, 2019 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-30610760

RESUMO

Several σ-hole and π-hole tetrel-bonded complexes with a base H2 CX (X=O, S, Se) have been studied, in which TH3 F (T=C-Pb) and F2 TO (T=C and Si) act as the σ-hole and π-hole donors, respectively. Generally, these complexes are combined with a primary tetrel bond and a weak H-bond. Only one minimum tetrel-bonded structure is found for TH3 F, whereas two minima tetrel-bonded complexes for some F2 TO. H2 CX is favorable to engage in the π-hole complex with F2 TO relative to TH3 F in most cases, and this preference further expands for the Si complex. Particularly, the double π-hole complex between F2 SiO and H2 CX (X=S and Se) has an interaction energy exceeding 500 kJ/mol, corresponding to a covalent-bonded complex with the huge orbital interaction and polarization energy. Both the σ-hole interaction and the π-hole interaction are weaker for the heavier chalcogen atom, while the π-hole interaction involving F2 TO (T=Ge, Sn, and Pb) has an opposite change. Both types of interactions are electrostatic in nature although comparable contributions from dispersion and polarization are respectively important for the weaker and stronger interactions.

6.
Int J Biometeorol ; 62(2): 177-182, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28887600

RESUMO

This study was designed to investigate the effects of sudden cooling on the physiological responses of 12 heat-stressed Holstein dairy cows using an isobaric tags for relative and absolute quantification (iTRAQ) labeling approach. Plasma samples were collected from these cows during heat stress (HS), and after strong, sudden cooling in the summer (16 days later). We compared plasma proteomic data before and after sudden cooling to identify the differentially abundant proteins. The results showed that sudden cooling in summer effectively alleviated the negative consequences of HS on body temperature and production variables. Expressions of plasma hemoglobin alpha and hemoglobin beta were upregulated, whereas lipopolysaccharide-binding protein (LBP) and haptoglobin were downregulated in this process. The increase of hemoglobin after cooling may improve oxygen transport and alleviate the rise in respiration rates in heat-stressed dairy cows. The decrease of LBP and haptoglobin suggests that the inflammatory responses caused by HS are relieved after cooling. Our findings provide new insight into the physiological changes that occur when heat-stressed dairy cows experience strong, sudden cooling.


Assuntos
Doenças dos Bovinos/prevenção & controle , Temperatura Baixa , Transtornos de Estresse por Calor/prevenção & controle , Transtornos de Estresse por Calor/veterinária , Proteínas de Fase Aguda , Animais , Proteínas de Transporte/sangue , Bovinos/sangue , Doenças dos Bovinos/sangue , Feminino , Haptoglobinas/análise , Transtornos de Estresse por Calor/sangue , Hemoglobinas/análise , Inflamação/sangue , Inflamação/prevenção & controle , Inflamação/veterinária , Glicoproteínas de Membrana/sangue , Proteômica
7.
Molecules ; 24(1)2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30577501

RESUMO

Carbon bonding is a weak interaction, particularly when a neutral molecule acts as an electron donor. Thus, there is an interesting question of how to enhance carbon bonding. In this paper, we found that the ⁻OCH3 group at the exocyclic carbon of fulvene can form a moderate carbon bond with NH3 with an interaction energy of about -10 kJ/mol. The ⁻OSiH3 group engages in a stronger tetrel bond than does the ⁻OGeH3 group, while a reverse result is found for both ⁻OSiF3 and ⁻OGeF3 groups. The abnormal order in the former is mainly due to the stronger orbital interaction in the ⁻OSiH3 complex, which has a larger deformation energy. The cyano groups adjoined to the fulvene ring not only cause a change in the interaction type, from vdW interactions in the unsubstituted system of ⁻OCF3 to carbon bonding, but also greatly strengthen tetrel bonding. The formation of tetrel bonding has an enhancing effect on the aromaticity of the fulvene ring.


Assuntos
Ciclopentanos/química , Carbono/química , Ligação de Hidrogênio , Modelos Moleculares , Eletricidade Estática
8.
Asian-Australas J Anim Sci ; 31(8): 1244-1251, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29514433

RESUMO

OBJECTIVE: The objective of the present study was to elucidate the mechanism underlying liver metabolic perturbations in dairy cows exposed to heat stress (HS). METHODS: Liquid chromatography massabl spectrometry was used to analyze metabolic differences in livers of 20 dairy cows, with and without exposure to HS. RESULTS: The results revealed 33 potential metabolite candidate biomarkers for the detection of HS in dairy cows. Fifteen of these metabolites (glucose, lactate, pyruvate, acetoacetate, ß-hydroxybutyrate, fumaric acid, citric acid, choline, glycine, proline, isoleucine, leucine, urea, creatinine, and orotic acid) were previously found to be potential biomarkers of HS in plasma or milk, discriminating dairy cows with and without HS. CONCLUSION: All the potential diagnostic biomarkers were involved in glycolysis, amino acid, ketone, tricarboxylic acid, or nucleotide metabolism, indicating that HS mainly affected energy and nucleotide metabolism in lactating dairy cows.

9.
Asian-Australas J Anim Sci ; 31(4): 505-513, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28920416

RESUMO

OBJECTIVE: This experiment investigated the effects of aflatoxin B1 (AFB1) alone or mixed with ochratoxin A (OTA) and/or zearalenone (ZEA) on the metabolism, immune function, and antioxidant status of dairy goats. METHODS: Fifty lactating Laoshan dairy goats were randomly assigned to one of five treatment groups (n = 10) for 14 days. Goats were fed no additive (control) or administered with 50 µg AFB1/kg dry matter (DM) (AFB1), 50 µg AFB1/kg DM+100 µg OTA/kg DM (AFB1+ OTA), 50 µg AFB1/kg DM+500 µg ZEA/kg DM (AFB1+ZEA), or 50 µg AFB1/kg DM+100 µg OTA/kg DM+500 µg ZEA/kg DM (AFB1+OTA+ZEA). RESULTS: Dry matter intake and milk production were lower in goats fed AFB1+OTA+ZEA than in controls. Supplementation with AFB1, OTA, and ZEA significantly decreased red blood cell count, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and mean platelet volume, and significantly increased white blood cell count, when compared with the control group. Compared with control, the combination of AFB1, OTA, and ZEA significantly increased alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities, total bilirubin (TBIL), interleukin-6, and malondialdehyde (MDA), but significantly reduced immunoglobulin A concentration, the activities of superoxide dismutase (SOD) and glutathione peroxides (GSH-Px), and total antioxidant capacity (T-AOC) in serum. Administration of AFB1 combined with OTA led to higher ALP, ALT, TBIL, and MDA, as well as lower milk production, SOD and GSH-Px activities, and T-AOC, than administration of AFB1 combined with ZEA. CONCLUSION: The mixture of AFB1, OTA, and ZEA exerted the greatest adverse effects on dairy goats, meanwhile the deleterious damage of the other mycotoxin combinations were in varying degrees. The findings of this study could provide guidance for the prevention and treatment of the consequences of contamination of animal feeds with combinations of mycotoxin.

10.
Chemphyschem ; 18(18): 2442-2450, 2017 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-28708276

RESUMO

The σ-hole tetrel bond in pyrazine/1,4-dicyanobenzene⋅⋅⋅TH3 F (T=C and Si) and the π-hole tetrel bond in pyrazine/1,4-dicyanobenzene⋅⋅⋅F2 TO have been compared. The π-hole tetrel bond is stronger than the corresponding σ-hole tetrel bond, with a larger interaction energy, shorter binding contact, greater electron density, and bigger charge transfer. Pyrazine forms a more stable tetrel-bonded complex than 1,4-dicyanobenzene even though the nitrogen atom in the former has a smaller negative electrostatic potential than the latter. An interesting cooperative effect was found when anion-π and tetrel-bond interactions coexisted in the same multicomponent complex of X- ⋅⋅⋅pyrazine/1,4-dicyanobenzene⋅⋅⋅TH3 F/F2 TO (X=F, Cl, and Br). Both interactions displayed a positive cooperative effect, as shown by the larger interaction energies, shorter binding separations, and greater electron densities. The enhancement in the tetrel bond is dependent on the strength of the anion-π interaction and it becomes larger in the order Br-

11.
J Dairy Res ; 84(4): 401-406, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29154733

RESUMO

The purposes of this study were to investigate the systemic and characteristic metabolites in the serum of dairy goats induced by aflatoxin B1 (AFB1) exposure and to further understand the endogenous metabolic alterations induced by it. A nuclear magnetic resonance (NMR)-based metabonomic approach was used to analyse the metabolic alterations in dairy goats that were induced by low doses of AFB1 (50 µg/kg DM). We found that AFB1 exposure caused significant elevations of glucose, citrate, acetate, acetoacetate, betaine, and glycine yet caused reductions of lactate, ketone bodies (acetate, ß-hydroxybutyrate), amino acids (citrulline, leucine/isoleucine, valine, creatine) and cell membrane structures (choline, lipoprotein, N-acetyl glycoproteins) in the serum. These data indicated that AFB1 caused endogenous metabolic changes in various metabolic pathways, including cell membrane-associated metabolism, the tricarboxylic acid cycle, glycolysis, lipids, and amino acid metabolism. These findings provide both a comprehensive insight into the metabolic aspects of AFB1-induced adverse effects on dairy goats and a method for monitoring dairy animals exposed to low doses of AFB1.


Assuntos
Aflatoxina B1/toxicidade , Aminoácidos/sangue , Carboidratos/sangue , Cabras/sangue , Peroxidação de Lipídeos/efeitos dos fármacos , Metabolômica , Acetatos/sangue , Animais , Glicemia/análise , Ácido Cítrico/sangue , Indústria de Laticínios , Exposição Ambiental , Corpos Cetônicos/sangue , Ácido Láctico/sangue , Espectroscopia de Ressonância Magnética , Redes e Vias Metabólicas/efeitos dos fármacos
12.
Biochem Biophys Res Commun ; 471(2): 296-302, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-26851364

RESUMO

In this work we employed a comparative proteomic approach to evaluate seasonal heat stress and investigate proteomic alterations in plasma of dairy cows. Twelve lactating Holstein dairy cows were used and the treatments were: heat stress (n = 6) in hot summer (at the beginning of the moderate heat stress) and no heat stress (n = 6) in spring natural ambient environment, respectively. Subsequently, heat stress treatment lasted 23 days (at the end of the moderate heat stress) to investigate the alterations of plasma proteins, which might be employed as long-term moderate heat stress response in dairy cows. Changes in plasma proteins were analyzed by two-dimensional electrophoresis (2-DE) combined with mass spectrometry. Analysis of the properties of the identified proteins revealed that the alterations of plasma proteins were related to inflammation in long-term moderate heat stress. Furthermore, the increase in plasma tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) directly demonstrated that long-term moderate heat stress caused an inflammatory response in dairy cows.


Assuntos
Doenças dos Bovinos/imunologia , Bovinos/sangue , Bovinos/imunologia , Citocinas/imunologia , Transtornos de Estresse por Calor/veterinária , Síndrome de Resposta Inflamatória Sistêmica/veterinária , Animais , Doenças dos Bovinos/sangue , Citocinas/sangue , Feminino , Transtornos de Estresse por Calor/sangue , Transtornos de Estresse por Calor/imunologia , Proteoma/imunologia , Síndrome de Resposta Inflamatória Sistêmica/sangue , Síndrome de Resposta Inflamatória Sistêmica/imunologia
13.
Phys Chem Chem Phys ; 18(16): 11348-56, 2016 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-27055488

RESUMO

Ab initio MP2/aug-cc-pVTZ calculations were performed to investigate the pnicogen-bonded complexes of PyZX2 (Py = pyridine, Z = P and As, X = H and F) and their protonated analogues. The selected Lewis bases include H2S, PH3, H2O, NH3, and H2CO. The relative stability of pnicogen-bonded complexes is related to the nature of PyZX2 and bases. When the nitrogen atom of the pyridine ring in PyZX2 is protonated, the protonated complexes are more stabilized than their neutral counterparts, with the interaction energies increased by 8.5-34.6 kJ mol(-1) and the binding distances shortened by 0.050-0.574 Å. Protonation strengthens the pnicogen bond, from a weak interaction to one of moderate strength. In the neutral complexes of PyZX2 and H2O, the formation of a N···H-O hydrogen bond is favorable compared to the pnicogen bond. Such inclination is more prominent in the complexes of protonated PyZX2 and NH3. In H2O···PyZX2···H2O, pnicogen bonding is strengthened by hydrogen bonding due to positive synergistic effects; however, in NH3···H(+)-PyZX2···NH3, pnicogen bonding is weakened by hydrogen bonding due to negative synergistic effects.

14.
J Chem Phys ; 145(22): 224310, 2016 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-27984914

RESUMO

The complexes of XH3F⋯N3-/OCN-/SCN- (X = C, Si, Ge, and Sn) have been investigated at the MP2/aug-cc-pVTZ(PP) level. The σ-hole of X atom in XH3F acts as a Lewis acid forming a tetrel bond with pseudohalide anions. Interaction energies of these complexes vary from -8 to -50 kcal/mol, mainly depending on the nature of X and pseudohalide anions. Charge transfer from N/O/S lone pair to X-F and X-H σ* orbitals results in the stabilization of these complexes, and the former orbital interaction is responsible for the large elongation of X-F bond length and the remarkable red shift of its stretch vibration. The tetrel bond in the complexes of XH3F (X = Si, Ge, and Sn) exhibits a significant degree of covalency with XH3F distorted significantly in these complexes. A breakdown of the individual forces involved attributes the stability of the interaction to mainly electrostatic energy, with a relatively large contribution from polarization. The transition state structures that connect the two minima for CH3Br⋯N3- complex have been localized and characterized. The energetic, geometrical, and topological parameters of the complexes were analyzed in the different stages of the SN2 reaction N3- + CH3Br → Br- + CH3N3.

15.
J Therm Biol ; 60: 103-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27503722

RESUMO

This experiment was conducted to investigate the effects of rumen-protected gamma-aminobutyric acid (GABA) on immune function and antioxidant status in heat-stressed dairy cows. Sixty Holstein dairy cows were randomly assigned to 1 of 4 treatments according to a completely randomized block design. The treatments consisted of 0 (control), 40, 80, or 120mg of GABA/kg DM from rumen-protected GABA. The trial lasted 10 weeks. The average temperature-humidity indices at 0700, 1400 and 2200h were 78.4, 80.2 and 78.7, respectively. Rectal temperatures decreased linearly at 0700, 1400, and 2200h with increasing GABA. As the GABA increased, the immunoglobulin (Ig) A and IgG contents and the proportions of CD4(+) and CD8(+) T lymphocytes increased linearly (P<0.05), whereas concentrations of interleukin (IL)-2, IL-4, IL-6 and tumor necrosis factor-α (TNF-α) decreased linearly (P<0.05). The activities of superoxide dismutase (SOD), glutathione-peroxidase (GSH-PX) and total antioxidant capacity (T-AOC) increased linearly (P<0.05), whereas malondialdehyde (MDA) content decreased linearly (P<0.05) with increasing GABA. These results indicate that rumen-protected GABA supplementation to heat-stressed dairy cows can improve their immune function and antioxidant activity.


Assuntos
Doenças dos Bovinos/prevenção & controle , Bovinos/fisiologia , GABAérgicos/uso terapêutico , Transtornos de Estresse por Calor/veterinária , Resposta ao Choque Térmico/efeitos dos fármacos , Ácido gama-Aminobutírico/uso terapêutico , Ração Animal/análise , Animais , Temperatura Corporal/efeitos dos fármacos , Relação CD4-CD8 , Bovinos/sangue , Bovinos/imunologia , Doenças dos Bovinos/sangue , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/metabolismo , Citocinas/sangue , Citocinas/imunologia , Suplementos Nutricionais/análise , Feminino , Transtornos de Estresse por Calor/imunologia , Transtornos de Estresse por Calor/metabolismo , Transtornos de Estresse por Calor/prevenção & controle , Temperatura Alta , Estresse Oxidativo/efeitos dos fármacos , Rúmen/efeitos dos fármacos
16.
World J Microbiol Biotechnol ; 32(1): 12, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26712627

RESUMO

A cellulase gene (cel28a) was isolated from a rumen microbial metagenome library of goat rumen microorganisms, cloned into E. coli, and expressed in active form. The gene has a length of 1596 bp obtained using a genome walking Kit and encodes a protein of 509 amino acids with a calculated MW of 55 kDa. The deduced amino acid sequence was homologous with cellulases belonging to the glycosyl hydrolase family 5 (GH5). The expressed protein showed activity toward carboxymethylcellulose (CMC) and xylan, suggesting non-specific endoglucanase activity. The optimal conditions for endoglucanase and xylanase activities were 50 °C and pH 5.0. The metal ions (Ca(2+), Fe(2+), Mn(2+) and Co(2+)) stimulated the cellulase activity of cel28a, while the other metal ions and chemicals (Ni(2+), Mg(2+), Zn(2+), Cu(2+), SDS and EDTA) inhibited the cellulase activity. Further examination of substrate preference showed a higher activity with CMC, oat spelt xylan and birchwood xylan than with filter paper and microcrystalline cellulose, again suggesting that the protein was an endoglucanase with xylanase activity.


Assuntos
Proteínas de Bactérias/isolamento & purificação , Celulase/isolamento & purificação , Cabras/microbiologia , Rúmen/microbiologia , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carboximetilcelulose Sódica/metabolismo , Celulase/química , Celulase/genética , Celulase/metabolismo , Celulose/metabolismo , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Metagenômica , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência , Especificidade por Substrato , Xilanos/metabolismo
17.
Acta Chim Slov ; 63(2): 271-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27333549

RESUMO

Quantum chemical calculations have been performed for the substitution reactions of the aluminum chlorogermylenoid H2GeClAlCl2 with HF, H2O, NH3, HCl, H2S, and PH3 to get more insights into the reactivity of H2GeClAlCl2. The theoretical calculated results indicated that the substitution reactions of H2GeClAlCl2 with HF, H2O, NH3, HCl, H2S, and PH3 proceeded in a concerted manner. There were one transition state and one intermediate which connected the reactants and the products along the potential energy surface. The six substitution reactions of H2GeClAlCl2 with HF, H2O, NH3, HCl, H2S, and PH3 are compared with the addition reaction s of H2Ge with these hydrides. And based on the calculated results we concluded that the substitution reactions of H2GeClAlCl2 with these hydrides involve two steps, one is dissociation onto H2Ge with AlCl3, and the other is the addition reactions of H2Ge with HF, H2O, NH3, HCl, H2S, and PH3.

18.
Chemphyschem ; 16(5): 1008-16, 2015 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-25677330

RESUMO

The interplay between cation-π and coinage-metal-oxygen interactions are investigated in the ternary systems N⋅⋅⋅PhCCM⋅⋅⋅O (N=Li(+), Na(+), Mg(2+); M=Ag, Au; O=water, methanol, ethanol). A synergetic effect is observed when cation-π and coinage-metal-oxygen interactions coexist in the same complex. The cation-π interaction in most triads has a greater enhancing effect on the coinage-metal-oxygen interaction. This effect is analyzed in terms of the binding distance, interaction energy, and electrostatic potential in the complexes. Furthermore, the formation, strength, and nature of both the cation-π and coinage-metal-oxygen interactions can be understood in terms of electrostatic potential and energy decomposition. In addition, experimental evidence for the coexistence of both interactions is obtained from the Cambridge Structural Database (CSD).

19.
J Phys Chem A ; 119(49): 11882-90, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26595194

RESUMO

In this work, the structures, energetics, and tautomerizations in 3-hydroxyisoquinoline (3HIQ) in both the ground state and the excited state have been theoretically investigated by the MP2, TDDFT, and CASPT2 methods, respectively. The solvent effect including the implicit solvent and explicit solvent on the structures, energetics, and tautomeizations are revealed. We found that the explicit solvent plays a more important role in the structures, energetics, and tautomerizations in 3HIQ than implicit solvent in both the ground state and the excited state. The proton transfer is more facilitated in explicit solvent (water or methanol) compared to that in the gas phase and in the implicit solvent in the excited state, and the reactive role of the molecular solvent is found to be related with the two linear hydrogen bonds.

20.
J Phys Chem A ; 119(11): 2217-24, 2015 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-25029257

RESUMO

A tetrel-hydride interaction was predicted and characterized in the complexes of XH3F···HM (X = C, Si, Ge, Sn; M = Li, Na, BeH, MgH) at the MP2/aug-cc-pVTZ level, where XH3F and HM are treated as the Lewis acid and base, respectively. This new interaction was analyzed in terms of geometrical parameters, interaction energies, and spectroscopic characteristics of the complexes. The strength of the interaction is essentially related to the nature of X and M groups, with both the larger atomic number of X and the increased reactivity of M giving rise to a stronger tetrel-hydride interaction. The tetrel-hydride interaction exhibits similar substituent effects to that of dihydrogen bonds, where the electron-donating CH3 and Li groups in the metal hydride strengthen the binding interactions. NBO analyses demonstrate that both BD(H-M) → BD*(X-F) and BD(H-M) → BD*(X-H) orbital interactions play the stabilizing role in the formation of the complex XH3F···HM (X = C, Si, Ge, and Sn; M = Li, Na, BeH, and MgH). The major contribution to the total interaction energy is electrostatic energy for all of the complexes, even though the dispersion/polarization parts are nonnegligible for the weak/strong tetrel-hydride interaction, respectively.

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