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1.
Chemistry ; 26(20): 4599-4606, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-31943433

RESUMO

This study reports a combined Cambridge Structural Database and theoretical DFT study of charge assisted chalcogen bonds involving sulfonium, selenonium, and telluronium cations. The chalcogen bond has been recently defined by IUPAC as the net attractive interaction between an electrophilic region associated with a chalcogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. Divalent chalcogen atoms typically have up to two σ-holes and forms up to two ChBs; the same holds for tetravalent chalcogens which adopt a seesaw arrangement. In sulfonium, selenonium, and telluronium salts chalcogen atoms form three covalent bonds, three σ-holes are located opposite to these bonds, and up to three charge assisted ChBs can be formed between these holes and the counterions. The covalent bond arrangement around these chalcogen atoms is similar to trivalent pnictogen atoms and translates into a similar pattern of noncovalent interactions. We have found and studied this type of charge-assisted chalcogen bonds in various sulfonium ion-containing inhibitors of glucosidase, for example, salacinol and kotalanol.


Assuntos
Cátions/química , Calcogênios/química , Glucosidases/antagonistas & inibidores , Calcogênios/análise , Modelos Moleculares
2.
J Food Sci ; 85(2): 324-331, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31968392

RESUMO

Anthocyanins in wine principally depend on grape skin extractable anthocyanin content, that is, the amount of anthocyanins present in grape skin that are released to wine during the maceration stage. This amount of extractable anthocyanins is closely linked to the cell wall degradation of skin cells. Indeed, among other methodologies, the maceration in presence of different enzymes can be used to increase cell wall degradation, and therefore, the amount of anthocyanins extracted from grape skins to wine. Vitis vinifera L. cv. Tempranillo and Syrah red grapes have been identified as samples with low anthocyanin extraction potential by near infrared hyperspectral imaging. Grape skins have been macerated in the presence of cellulase, glucosidase, and pectinase. Then, color of the supernatants and phenolic compounds extracted from grape skins (total phenols, total flavanols, and total and individual anthocyanins) has been determined. Cellulase and glucosidase have shown a positive effect in the extraction of phenolic compounds from these grapes. Macerations carried out in the presence of cellulase have produced supernatants with a more intense color (lower lightness and higher chroma values), and a higher extraction of flavanols and anthocyanins than the respective control essays. However, pectinase treatments have produced the opposite effect, which could be partially explained by an eventual interaction between the cell wall polysaccharides liberated by pectinase and the phenolic compounds extracted. Synergy effects do not appear between cellulase and glucosidase. Moreover, the negative effect of the addition of pectinase might be due to the interactions between the cell wall material liberated by pectinase and the phenolic compounds extracted. PRACTICAL APPLICATION: In the present study, grape samples with a low anthocyanin extraction potential have been identified, and these samples have been macerated in the presence of different enzymes. The applied enzymes were three of the most common enzymes that are applied in the wine industry. Individual enzymes and mixtures have been applied to Syrah and Tempranillo grape skin samples and the results have been compared to control macerations. Knowledge in this topic will help the production of quality wines.


Assuntos
Antocianinas/análise , Antocianinas/isolamento & purificação , Fenóis/análise , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Vitis/química , Biocatálise , Celulase/química , Cor , Frutas/química , Glucosidases/química , Fenóis/química , Poligalacturonase/química , Vinho/análise
3.
Gene ; 726: 144192, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31669635

RESUMO

In the Carbohydrate-Active enZymes database (CAZy) glycoside hydrolases (GHs) are classified presently into 156 GH families. In human, there are five known enzymes from the family GH31. Two (MGAM and SI) are intestinal glucosidases involved in saccharide digestion, the acidic glucosidase (GAA) is responsible for glycogen degradation in lysosomes and GANAB (glucosidase II) plays a role in the control of a proper protein folding in the endoplasmic reticulum. The fifth protein is called GANC. It is an α-glucosidase, which is able to release the terminal glucose from maltotriose and glycogen at neutral pH. Its subcellular localization and its physiological function have not been reported in scientific literature yet. Our phylogenetic analysis shows that GANC evolved in early vertebrates from the α-subunit of GANAB. We have thus used an in silico approach to identify changes leading from the α-subunit of GANAB to GANC. We have also searched for residues and regions, which are conserved and under influence of negative selection pressure and which could be important for the function of the enzymes. We have found three residues, which could be responsible for the difference in the substrate specificity reported between the α-subunit of GANAB and GANC. We have also retrieved expression and subcellular localization data, from the Human Protein Atlas database, which shows differences in the expression profiles between GANAB and GANC. Unlike GANAB, GANC seems to be expressed in the nucleoplasm and in the cytoplasm where it colocalizes with actin filaments. The signal sequence and the nuclear localization signal have also been analyzed.


Assuntos
Glucosidases/genética , alfa-Glucosidases/genética , Sequência de Aminoácidos , Animais , Simulação por Computador , Humanos , Filogenia , Dobramento de Proteína , Subunidades Proteicas/genética , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Vertebrados/genética
4.
Food Chem ; 305: 125462, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31618694

RESUMO

The objectives of this research were to demonstrate the changes in isoflavone-aglycones, total phenolics, and biological properties (digestive enzyme inhibition; antioxidant) from six organs including leaves, leafstalks, roots, stems, seeds, and pods at different growth times of soybean plant. Three isoflavone-aglycones in microwave-assisted acid hydrolysis extracts were elucidated using UHPLC-ESI-Q-TOF-MS/MS and their contents exhibited remarkable differences in leaves (245.93-2239.33 µg/g), roots (854.96-4425.34 µg/g), and seeds (ND-2339.62 µg/g). Specifically, the collected samples on 15-Oct (leaves: 2239.33; seeds: 2339.62 µg/g) and 31-Aug (roots: 4425.34 µg/g) showed the highest isoflavone-aglycones, and daidzein was observed the most abundant component, comprising approximately 70%. Moreover, the inhibitions against α-glucosidase and α-amylase displayed the predominant effects in roots (89;91%) and leaves (81;85%) of samples on 31-Aug and 15-Oct at 300 µg/ml. The antioxidant activities on ABTS, DPPH, and hydroxyl radicals increased considerably with the increases of growth times in leaves and seeds, especially, ABTS showed the highest scavenging abilities: leaves (15-Oct;83%) > roots (31-Aug;75%) > seeds (15-Oct;68%). Therefore, our results suggest that soybean leaves, roots and seeds may be considered as excellent natural sources for nutraceuticals.


Assuntos
Antioxidantes/química , Glucosidases/metabolismo , Isoflavonas/análise , Micro-Ondas , Soja/química , Cromatografia Líquida de Alta Pressão , Glucosidases/antagonistas & inibidores , Hidrólise , Isoflavonas/metabolismo , Fenóis/análise , Folhas de Planta/química , Folhas de Planta/metabolismo , Sementes/química , Sementes/metabolismo , Soja/crescimento & desenvolvimento , Soja/metabolismo , Espectrometria de Massas em Tandem/métodos
5.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(5): 714-719, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31762243

RESUMO

OBJECTIVE: To select and identify the bacterium which highly produces protease and ß-D-glucosidase from 72 strains of Shuidouchi from Sichuan, and to provide evidence for further research on its nutritional value and fermentation strain exploiting. METHODS: Casein degradation test and pNPG chemical test were applied respectively to detect the capacity to produce protease and ß-D-glucosidase of each strain. Characteristics of morphology, biochemistry, 16S rRNA and MALDI-TOF-MS were used to identify the fermentation strain, which genetic stability, curves of growth and enzyme producing were also obtained. RESULTS: The strain with the highest enzyme activity of ß-D-glucosidase (0.084 U/L) among the top 10 strains for producing protease was selected as the fermentation strain and was identified as Bacillus subtilis, which curves of growth and enzyme producing conformed as well. The result of genetic stability showed that capacity of enzyme producing was stable until the 10th generation. CONCLUSIONS: The fermentation strain which highly produced protease and ß-D-glucosidase was selected from 72 strains of shuidouchi from Sichuan and was identified as Bacillus subtilis.


Assuntos
Bacillus subtilis/enzimologia , Alimentos e Bebidas Fermentados/microbiologia , Glucosidases/biossíntese , Peptídeo Hidrolases/biossíntese , Alimentos de Soja/microbiologia , China , Fermentação , RNA Ribossômico 16S
6.
Environ Pollut ; 255(Pt 2): 113321, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31610515

RESUMO

Ionic liquids (ILs) are extensively used in several chemistry fields. And research about the effects of ILs on soil microbes is needed. In this study, brown soil was exposed to 1-butyl-3-methylimidazolium bromide ([C4mim]Br), 1-hexyl-3-methylimidazolium bromide ([C6mim]Br) and 1-decyl-3-methylimidazolium bromide ([C10mim]Br). The toxicities of the three ILs are evaluated by measuring the soil culturable microbial number, enzyme activity, microbial diversity and, abundance of the ammonia monooxygenase (amoA) genes of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). Results showed that all tested ILs caused a decrease in culturable microbial abundance. Tested ILs exposure inhibit urease activity and promote acid phosphatase and ß-glucosidase activities. Tested ILs reduced soil microbial diversity and the abundances of AOB-amoA and AOA-amoA genes significantly. After a comparison of the integrated biomarker response (IBR) index, the toxicities of tested ILs to soil microorganisms were as follows: [C10mim]Br > [C6mim]Br > [C4mim]Br. Among all collected biomarkers, the abundance of the AOA-amoA gene was the most sensitive one and was easily affected after ILs exposure.


Assuntos
Archaea/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Boratos/toxicidade , Brometos/toxicidade , Imidazóis/toxicidade , Líquidos Iônicos/toxicidade , Fosfatase Ácida/metabolismo , Amônia/metabolismo , Glucosidases/metabolismo , Oxirredução , Oxirredutases/genética , Filogenia , Solo/química , Microbiologia do Solo , Urease/antagonistas & inibidores
7.
Int J Mol Sci ; 20(18)2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31500233

RESUMO

Helicobacter pylori colonises the human stomach and has tropism for the gastric mucin, MUC5AC. The majority of organisms live in the adherent mucus layer within their preferred location, close to the epithelial surface where the pH is near neutral. Trefoil factor 1 (TFF1) is a small trefoil protein co-expressed with the gastric mucin MUC5AC in surface foveolar cells and co-secreted with MUC5AC into gastric mucus. Helicobacter pylori binds with greater avidity to TFF1 dimer, which is present in gastric mucus, than to TFF1 monomer. Binding of H. pylori to TFF1 is mediated by the core oligosaccharide subunit of H. pylori lipopolysaccharide at pH 5.0-6.0. Treatment of H. pylori lipopolysaccharide with mannosidase or glucosidase inhibits its interaction with TFF1. Both TFF1 and H. pylori have a propensity for binding to mucins with terminal non-reducing α- or ß-linked N-acetyl-d-glucosamine or α-(2,3) linked sialic acid or Gal-3-SO42-. These findings are strong evidence that TFF1 has carbohydrate-binding properties that may involve a conserved patch of aromatic hydrophobic residues on the surface of its trefoil domain. The pH-dependent lectin properties of TFF1 may serve to locate H. pylori deep in the gastric mucus layer close to the epithelium rather than at the epithelial surface. This restricted localisation could limit the interaction of H. pylori with epithelial cells and the subsequent host signalling events that promote inflammation.


Assuntos
Helicobacter pylori/fisiologia , Lipopolissacarídeos/metabolismo , Estômago/microbiologia , Fator Trefoil-1/metabolismo , Mucinas Gástricas/metabolismo , Glucosidases/farmacologia , Helicobacter pylori/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Lipopolissacarídeos/química , Manosidases/farmacologia , Mucina-5AC/metabolismo , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo , Ligação Proteica/efeitos dos fármacos , Multimerização Proteica , Fator Trefoil-1/química , Tropismo
8.
Nat Commun ; 10(1): 3185, 2019 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-31320625

RESUMO

Unfolded protein response (UPR) is an adaptive mechanism that aims at restoring ER homeostasis under severe environmental stress. Malignant cells are resistant to environmental stress, which is largely due to an activated UPR. However, the molecular mechanisms by which different UPR branches are selectively controlled in tumor cells are not clearly understood. Here, we provide evidence that PRKCSH, previously known as glucosidase II beta subunit, functions as a regulator for selective activation of the IRE1α branch of UPR. PRKCSH boosts ER stress-mediated autophosphorylation and oligomerization of IRE1α through mutual interaction. PRKCSH contributes to the induction of tumor-promoting factors and to tumor resistance to ER stress. Increased levels of PRKCSH in various tumor tissues are positively correlated with the expression of XBP1-target genes. Taken together, our data provide a molecular rationale for selective activation of the IRE1α branch in tumors and adaptation of tumor cells to severe environmental stress.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Transformação Celular Neoplásica/patologia , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/metabolismo , Glucosidases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Resposta a Proteínas não Dobradas/fisiologia , Animais , Proteínas de Ligação ao Cálcio/genética , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Endorribonucleases/genética , Glucosidases/genética , Células Hep G2 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/patologia , Proteínas Serina-Treonina Quinases/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Transdução de Sinais/genética
9.
Food Chem ; 297: 125018, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253265

RESUMO

Different Ohmic heating conditions (OH, 10, 100, and 1000 Hz at 25 V; 45, 60, and 80 V at 60 Hz) were assessed to manufacture whey-raspberry flavored beverages. The inhibition of α-glucosidase, α-amylase, and angiotensin-converting I enzymes, antioxidant capacity, fatty acid profile, and volatile organic compounds (VOCs) were determined. OH treated samples presented lower anthocyanins content than the conventional treatment (2.91 ±â€¯0.23 mg/g), while the mild-intermediate conditions (10,100-Hz at 25 V and 45,60-V at 60 Hz) presented the highest chemical antioxidant activity when compared to the extreme processing conditions (1000 Hz-25 V and 80 V-60 Hz). OH led to an increase of 10% in both α-glucosidase (>99%) and α-amylase (≥70%). Among the VOCs, furfural and 5-hydroxymethylfurfural, a major intermediate Maillard reaction product was found in all treatments. Overall, OH can be used in the processing of whey-flavored raspberry beverages.


Assuntos
Bebidas/análise , Aromatizantes/química , Rubus/química , Soro do Leite/química , Antocianinas/análise , Antioxidantes/química , Culinária , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas , Glucosidases/antagonistas & inibidores , Glucosidases/metabolismo , Ondas de Rádio , Temperatura , Compostos Orgânicos Voláteis/análise , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo
10.
Carbohydr Res ; 480: 42-53, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31174176

RESUMO

Sulfolobus solfataricus ß-glycosidase (SS-ßGly) belongs to Glycosyl Hydrolase family1 (GH1) with broad substrate specificity. SS-ßGly catalyzes both hydrolysis and transglycosylation reactions. SS-ßGly is commonly used to synthesize variety of galacto-oligosaccharides. A comparison of SS-ßGly with bacterial and eukaryotic homologs, using DALI search, revealed unique inserts. Free enzyme molecular dynamics (MD) simulation was performed under two different pH conditions (pH 6.5 and 2.5) at a constant temperature of 65 °C using GROMACS. A probable active-site loop (residues 331-364) in SS-ßGly was identified. Dynamics of substrate binding cavity revealed that it was buried and inaccessible during most timeframes at pH 6.5 whereas open and accessible at pH 2.5. New cavities identified during both simulations may act as probable water channel or product egress path. Analyses of docked complexes of 3D structures obtained at every 1ns interval with compounds, involved in hydrolysis and tranglycosylation reactions, demonstrated that conformational states sampled by SS-ßGly during free enzyme dynamics mimic the stages in enzyme catalysis thereby providing a mechanistic perspective. Current study revealed that conformational changes were conducive for hydrolysis at pH 6.5 and multiple cycles of transglycosylation at pH 2.5. Probable role of salt-bridge interactions in determining the type of reaction mechanism was also explored.


Assuntos
Biocatálise , Glucosidases/química , Glucosidases/metabolismo , Simulação de Dinâmica Molecular , Sequência de Aminoácidos , Domínio Catalítico , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Especificidade por Substrato
11.
Nat Commun ; 10(1): 2222, 2019 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-31110237

RESUMO

Substrates associate and products dissociate from enzyme catalytic sites rapidly, which hampers investigations of their trajectories. The high-resolution structure of the native Hordeum exo-hydrolase HvExoI isolated from seedlings reveals that non-covalently trapped glucose forms a stable enzyme-product complex. Here, we report that the alkyl ß-D-glucoside and methyl 6-thio-ß-gentiobioside substrate analogues perfused in crystalline HvExoI bind across the catalytic site after they displace glucose, while methyl 2-thio-ß-sophoroside attaches nearby. Structural analyses and multi-scale molecular modelling of nanoscale reactant movements in HvExoI reveal that upon productive binding of incoming substrates, the glucose product modifies its binding patterns and evokes the formation of a transient lateral cavity, which serves as a conduit for glucose departure to allow for the next catalytic round. This path enables substrate-product assisted processive catalysis through multiple hydrolytic events without HvExoI losing contact with oligo- or polymeric substrates. We anticipate that such enzyme plasticity could be prevalent among exo-hydrolases.


Assuntos
Domínio Catalítico , Glucosidases/metabolismo , Modelos Moleculares , Proteínas de Plantas/metabolismo , Biocatálise , Cristalografia por Raios X , Ensaios Enzimáticos/métodos , Glucosidases/química , Glucosidases/isolamento & purificação , Glicosídeos/metabolismo , Hordeum/metabolismo , Simulação de Dinâmica Molecular , Ressonância Magnética Nuclear Biomolecular , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Plântula/metabolismo , Especificidade por Substrato
12.
Adipocyte ; 8(1): 190-200, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31037987

RESUMO

Long-term weight loss maintenance is a problem of overweight and obesity. Changes of gene expression during weight loss (WL) by calorie restriction (CR) are linked to the risk of weight regain (WR). However, detailed information on genes/proteins involved in the mechanism is still lacking. Therefore, we developed an in-vitro model system for glucose restriction (GR) and refeeding (RF) to uncover proteome differences between GR with RF vs normal feeding, of which we explored the relation with WR after WL. Human Simpson-Golabi-Behmel Syndrome cells were subjected to changing levels of glucose to mimic the condition of CR and RF. Proteome profiling was performed by liquid chromatography tandem mass spectrometry. This in-vitro model revealed 44 proteins differentially expressed after GR and RF versus feeding including proteins of the focal adhesions. Four proteins showed a persistent up- or down-regulation: liver carboxylesterase (CES1), mitochondrial superoxide dismutase [Mn] (SOD2), alpha-crystallin B-chain (CRYAB), alpha-enolase (ENO1). In-vivo weight loss-induced RNA expression changes linked CES1, CRYAB and ENO1 to WR. Moreover, of these 44 proteins, CES1 and glucosidase II alpha subunit (GANAB) during follow up correlated with WR. Correlation clustering of in-vivo protein expression data indicated an interaction of these proteins with structural components of the focal adhesions and cytoplasmic filaments in the adipocytes.


Assuntos
Adipócitos/metabolismo , Biomarcadores Tumorais/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Proteínas de Ligação a DNA/metabolismo , Glucose/deficiência , Glucosidases/metabolismo , Fosfopiruvato Hidratase/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ganho de Peso , Cadeia B de alfa-Cristalina/metabolismo , Adipócitos/citologia , Biomarcadores Tumorais/genética , Hidrolases de Éster Carboxílico/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Glucose/metabolismo , Glucosidases/genética , Humanos , Fosfopiruvato Hidratase/genética , Proteínas Supressoras de Tumor/genética , Cadeia B de alfa-Cristalina/genética
13.
Arch Oral Biol ; 102: 122-127, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31004977

RESUMO

OBJECTIVES: Approximately 25% of the adolescents in the Scandinavian population are treated with a fixed orthodontic appliance (FOA). Adverse effects such as enamel decalcification (white spot lesions - WSL), seem to affect over 30% of patients. WSL have only a limited ability to improve, thus seriously jeopardising the treatment outcome. The aim of present study was to explore the biofilm phenotype by investigating plaque collected: 1) adjacent to brackets, and 2) in gingival margin of maxillary incisors in adolescents with FOA. Incidence of WSL after treatment was also assessed. DESIGN: In eight adolescent patients treated with FOA, supra-gingival plaque formed on: 1) brackets, and 2) along the gingival margin of the maxillary incisors, was collected after 6-8 months of treatment. The patients were documented before and after treatment by intraoral photos. Plaque samples were tested for glycosidase- (fluorogenic substrates) and protease (FITC-labelled casein substrate) activities. The plaque samples were visualised by Live/Dead BacLight stain, following which cells were investigated by confocal scanning laser microscopy. RESULTS: In the collected plaque samples, all enzymes tested displayed small variations in activity between the individuals, except glucosidases, which varied significantly. Four patients developed WSL. The patients displayed higher glucosidase activity in plaque of brackets compared to patients without WSL. In seven patients, plaque at the gingival margin displayed higher protease activity than plaque of brackets. CONCLUSIONS: The current study shows two distinct environmentally induced biofilm phenotypes: 1) brackets with higher glucosidase activity, and 2) gingival margin with higher protease activity. Glucosidase activity might thus be used as a putative biomarker for risk of WSL.


Assuntos
Biofilmes , Cárie Dentária , Adolescente , Biomarcadores , Glucosidases , Humanos , Aparelhos Ortodônticos , Aparelhos Ortodônticos Fixos
14.
J Microbiol Biotechnol ; 29(4): 562-570, 2019 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-30955258

RESUMO

ß-Glucosylglycerol (ß-GG) and their derivatives have potential applications in food, cosmetics and the healthcare industry, including antitumor medications. In this study, ß-GG and its unnatural glycosides were synthesized through the transglycosylation of two enzymes, Sulfolobus shibatae ß-glycosidase (SSG) and Deinococcus geothermalis amylosucrase (DGAS). SSG catalyzed a transglycosylation reaction with glycerol as an acceptor and cellobiose as a donor to produce 56% of ß-GGs [ß-D-glucopyranosyl-(1→1/3)-D-glycerol and ß-D-glucopyranosyl- (1→2)-D-glycerol]. In the second transglycosylation reaction, ß-D-glucopyranosyl-(1 → 1/3)-Dglycerol was used as acceptor molecules of the DGAS reaction. As a result, 61% of α-Dglucopyranosyl-( 1→4)-ß-D-glucopyranosyl-(1→1/3)-D-glycerol and 28% of α-D-maltopyranosyl- (1→4)-ß-D-glucopyranosyl-(1→1/3)-D-glycerol were synthesized as unnatural glucosylglycerols. In conclusion, the combined enzymatic synthesis of the unnatural glycosides of ß-GG was established. The synthesis of these unnatural glycosides may provide an opportunity to discover new applications in the biotechnological industry.


Assuntos
Glucosídeos/biossíntese , Glucosiltransferases/metabolismo , Glicosídeo Hidrolases/metabolismo , Glicosídeos/biossíntese , Biotecnologia , Celobiose/metabolismo , Deinococcus/enzimologia , Deinococcus/genética , Escherichia coli/genética , Glucosidases/metabolismo , Glucosídeos/análise , Glucosídeos/química , Glucosiltransferases/genética , Glicerol/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeos/análise , Glicosídeos/química
15.
Physiol Plant ; 166(1): 105-119, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30834537

RESUMO

The maximum quantum yield of photosystem II (as reflected by variable to maximum chlorophyll a fluorescence, Fv /Fm ) is regarded as one of the most important photosynthetic parameters. The genetic basis underlying natural variation in Fv /Fm , which shows low level of variations in plants under non-stress conditions, is not easy to be exploited using the conventional gene cloning approaches. Thus, in order to answer this question, we have followed another strategy: we used genome-wide association study (GWAS) and transgenic analysis in a rice mini-core collection. We report here that four single-nucleotide polymorphisms, located in the promoter region of ß-glucosidase 5 (BGlu-5), are associated with observed variation in Fv /Fm . Indeed, our transgenic analysis showed a good correlation between BGlu-5 and Fv /Fm . Thus, our work demonstrates the feasibility of using GWAS to study natural variation in Fv /Fm , suggesting that cis-element polymorphism, affecting the BGlu-5 expression level, may, indirectly, contribute to Fv /Fm variation in rice through the gibberellin signaling pathway. Further research is needed to understand the mechanism of our novel observation.


Assuntos
Estudo de Associação Genômica Ampla/métodos , Glucosidases/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Celulases/genética , Celulases/metabolismo , Giberelinas/metabolismo , Glucosidases/genética , Complexo de Proteína do Fotossistema II/genética , Polimorfismo de Nucleotídeo Único/genética
16.
Int J Biol Macromol ; 130: 499-507, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30826402

RESUMO

Potato starch displayed high viscosity, low hydroscopicity and dispersity, and acid susceptibility leading to the limited application of potato starch. To expand the potato starch utility with appropriate processing characteristics, potato starch granules were modified with branching enzyme (BE) and transglucosidase (TG). The results indicated that the susceptibility of potato starch granules to TG was higher than BE. Moreover, the two enzymes showed the synergistic effect in enzymatic modification of potato starch granules. They cooperatively attacked the external and interior of potato starch granules. The crystal forms of potato starch changed from B to C-type after double enzyme treatments, and enzyme-treated starches exhibited homogeneous crystal distribution. Compared to BE or TG alone, the combined action of BE and TG increased significantly the ratio of α-1,6-glycosidic linkage and the amounts of short chains of potato starch, which led to the significant reduction in degree of crystallinity, viscosity, gelatinization temperature and enthalpy, and a remarkable increase in solubility. Especially, the physicochemical characteristics of modified starch largely depended on the treatment time of TG. Thus, through the combination of BE and TG, the appropriate treatment time of TG may be chosen to improve the physicochemical properties of potato starch in processed starch-based products.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/química , Glucosidases/química , Solanum tuberosum/química , Amido/química , Fenômenos Químicos , Hidrólise , Reologia , Solubilidade , Termodinâmica
17.
Molecules ; 24(3)2019 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-30682802

RESUMO

Desert soil is one of the most severe conditions which negatively affect the environment and crop growth production in arid land. The application of organic amendments with inorganic fertilizers is an economically viable and environmentally comprehensive method to develop sustainable agriculture. The aim of this study was to assess whether milk tea waste (TW) amendment combined with chemical fertilizer (F) application can be used to improve the biochemical properties of sandy soil and wheat growth. The treatments included control without amendment (T1), chemical fertilizers (T2), TW 2.5% + F (T3), TW 5% + F (T4) and TW 10% + F (T5). The results showed that the highest chlorophyll (a and b) and carotenoids, shoot and root dry biomass, and leaf area index (LAI) were significantly (p < 0.05) improved with all amendment treatments. However, the highest root total length, root surface area, root volume and diameter were recorded for T4 among all treatments. The greater uptake of N, P, and K contents for T4 increased for the shoot by 68.9, 58.3, and 57.1%, and for the root by 65.7, 34.3, and 47.4% compared to the control, respectively. Compared with the control, T5 treatment decreased the soil pH significantly (p < 0.05) and increased soil enzyme activities such as urease (95.2%), ß-glucosidase (81.6%) and dehydrogenase (97.2%), followed by T4, T3, and T2. Our findings suggested that the integrated use of milk tea waste and chemical fertilizers is a suitable amendment method for improving the growth and soil fertility status of sandy soils.


Assuntos
Fertilizantes/análise , Leite/química , Solo/química , Resíduos Sólidos , Chá/química , Triticum/crescimento & desenvolvimento , Agricultura , Animais , Biomassa , Carotenoides/metabolismo , Clorofila/metabolismo , Glucosidases/metabolismo , Nitrogênio/química , Nutrientes/química , Oxirredutases/metabolismo , Fósforo/química , Potássio/química , Urease/metabolismo
18.
Int J Mol Sci ; 20(3)2019 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-30678336

RESUMO

Four novel acylglycosides flavones (AGFs) including two quercetin acylglycosides and two kaempferol acylglycosides were isolated from Fuzhuan brick tea (FBT) as follows: quercetin 3-O-[α-l-rhamnopyranosyl (1→3)] [2-O''-(E)-p-coumaroyl] [ß-d-glucopyranosyl (1→3)-α-l-rhamnopyranosyl (1→6)]-ß-d-galactoside was named as camelliquercetiside E (1), quercetin 3-O-[α-l-rhamnopyranosyl (1→3)] [2-O''-(E)-p-coumaroyl] [α-l-rhamnopyranosyl (1→6)]-ß-d-galactoside was named as camelliquercetiside F (2), kaempferol 3-O-[α-l-arabinopyranosyl (1→3)] [2-O''-(E)-p-coumaroyl] [ß-d-glucopyranosyl (1→3)-α-l-rhamnopyranosyl (1→6)]-ß-d-glucoside was named as camellikaempferoside D (3), kaempferol 3-O-[α-l-arabinopyranosyl (1→3)] [2-O''-(E)-p-coumaroyl] [α-l-rhamnopyranosyl (1→6)]-ß-d-glucoside was named as camellikaempferoside E (4). Chemical structures of AGFs were identified by time-of-flight mass (TOF-MS) and NMR spectrometers (¹H NMR, 13C NMR, ¹H-¹H COSY, HMBC and HSQC), and the MS² fragmentation pathway of AGFs was further investigated. The inhibitory abilities of AGFs and their proposed metabolites on α-glucosidase and HMG-CoA reductase were analyzed by molecular docking simulation, and the results suggested that inhibitory activities of AGFs were significantly affected by acyl structure, number of glycosyl and conformation, and part of them had strong inhibitory activities on α-glucosidase and HMG-CoA reductase, suggesting that AGFs and their metabolites might be important ingredients that participate in the regulation of hypoglycemic and hypolipidemic effects. The results provided new AGFs and research directions for the practical study of FBT health functions in future.


Assuntos
Quempferóis/farmacologia , Simulação de Acoplamento Molecular , Quercetina/farmacologia , Chá/química , Acil Coenzima A/química , Acil Coenzima A/metabolismo , Camellia sinensis/química , Glucosidases/química , Glucosidases/metabolismo , Glicosídeos/química , Humanos , Quempferóis/química , Ligação Proteica , Quercetina/análogos & derivados
19.
Food Chem ; 274: 543-546, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30372976

RESUMO

Apiosidases are glycosidases relevant for aroma development during fermentation of wines and black tea. Reaction mechanism of apiosidase from Aspergillus aculeatus in commercial glycanase Viscozyme L was studied by 1H NMR technique. Study of hydrolysis of 4-nitrophenyl ß-D-apiofuranoside revealed that this reaction proceeds with inversion of hydroxyl group in the anomeric center, which confirms inverting mechanism of the enzyme and its inability to catalyze transapiosylation in syntheses of apiosides.


Assuntos
Aspergillus/enzimologia , Glucosidases/metabolismo , Fermentação , Glicosídeos/metabolismo , Hidrólise
20.
Bioprocess Biosyst Eng ; 42(3): 345-354, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30523449

RESUMO

Maltooligosyl trehalose trehalohydrolase (MTHase, EC 3.2.1.141) catalyzes the release of trehalose, a novel food ingredient, by splitting the α-1,4-glucosidic linkage adjacent to the α-1,1-glucosidic linkage of maltooligosyl trehalose. However, the high-yield preparation of recombinant MTHase has not yet been reported. In this study, a codon-optimized synthetic gene encoding Sulfolobus acidocaldarius MTHase was expressed in Escherichia coli. In initial expression experiments conducted using pET-24a (+) and E. coli BL21 (DE3), the MTHase activity was 10.4 U/mL and a large amount of the expression product formed inclusion bodies. The familiar strategies, including addition of additives, co-expression with molecular chaperones, and expression with a fusion partner, failed to enhance soluble MTHase expression. Considering the intermolecular disulfide bond of MTHase, expression was investigated using a system comprising plasmid pET-32a (+) and host E. coli Origami (DE3), which is conducive to cytoplasmic disulfide bond formation. The MTHase activity increased to 55.0 U/mL, a 5.3-fold increase. Optimization of the induction conditions in a 3-L fermentor showed that when the lactose was fed at 0.2 g/L/h beginning at an OD600 of 40 and the induction temperature was maintained at 30 °C, the MTHase activity reached a maximum of 204.6 U/mL. This is the first report describing a systematic effort to obtain high-efficiency MTHase production. The high yield obtained using this process provides the basis for the industrial-scale production of trehalose. This report is also expected to be valuable in the production of other enzymes containing disulfide bonds.


Assuntos
Proteínas de Bactérias/biossíntese , Escherichia coli/metabolismo , Expressão Gênica , Glucosidases/biossíntese , Sulfolobus acidocaldarius/genética , Proteínas de Bactérias/genética , Escherichia coli/genética , Glucosidases/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Sulfolobus acidocaldarius/enzimologia
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