Novel xylan degrading enzymes from polysaccharide utilizing loci of Prevotella copri DSM18205

AbstractPrevotella copri DSM18205 is a bacterium, classified under Bacteroidetes that can be found in the human gastrointestinal tract (GIT). The role of P. copri in the GIT is unclear, and elevated numbers of the microbe have been reported both in dietary fiber-induced improvement in glucose metabolism but also in conjunction with certain inflammatory conditions. These findings raised our interest in investigating the possibility of P. copri to grow on xylan, and identify the enzyme systems playing a role in digestion of xylan-based dietary fibers in P. copri, which currently are unexplored. Two xylan degrading polysaccharide utilizing loci (PUL10 and 15) were found in the genome, with three and eight GH-encoding genes, respectively. Three of the eight gene products were successfully produced in Escherichia coli: One monomeric two-domain extracellular enzyme from GH43 (subfamily 12, in PUL10, 60 kDa) and two dimeric single module enzymes from PUL15, one extracellular GH10 (41 kDa), and one intracellular GH43 subfamily 1 enzyme (37 kDa). The GH43_12 enzyme was hydrolysing arabinofuranose residues from different substrates, and a model of the 3D-structure revealed a single arabinose binding pocket. The GH10 (1) and GH43_1 are cleaving the xylan backbone. Hydrolysis products of GH10 (1) were DP2-4, and seven subsites (−3 to +4) were predicted in the 3D-model of the GH10 active site. GH43_1 mainly produced xylose (in line with its intracellular location). Based on our results we propose that in PUL15, GH10 (1) is an extracellular endo-1,4-β-xylanase, that hydrolyses mainly glucuronosylated xylan polymers to xylooligosaccharides (XOS); while, GH43_1 in the same PUL, is an intracellular β-xylosidase, catalysing complete hydrolysis of the XOS to xylose. In PUL10, the characterized GH43_12 is an arabinofuranosidase, with a role in degradation of arabinoxylan, catalysing removal of arabinose-residues on xylan polymers.

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Cysteine-10 on 17β-Hydroxysteroid Dehydrogenase 1 Has Stabilizing Interactions in the Cofactor Binding Region and Renders Sensitivity to Sulfhydryl Modifying Chemicals

International Journal of Cell Biology ◽

10.1155/2013/769536 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Lyubomir G. Nashev ◽

Atanas G. Atanasov ◽

Michael E. Baker ◽

Alex Odermatt

Keyword(s):

Structure Function ◽

Enzyme Inhibitors ◽

3D Structure ◽

Hydroxysteroid Dehydrogenase ◽

Binding Pocket ◽

Cysteine Residue ◽

Kinetic Properties ◽

Binding Region ◽

Cofactor Binding

17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the conversion of estrone to the potent estrogen estradiol. 17β-HSD1 is highly expressed in breast and ovary tissues and represents a prognostic marker for the tumor progression and survival of patients with breast cancer and other estrogen-dependent tumors. Therefore, the enzyme is considered a promising drug target against estrogen-dependent cancers. For the development of novel inhibitors, an improved understanding of the structure-function relationships is essential. In the present study, we examined the role of a cysteine residue, Cys10, in the Rossmann-fold NADPH binding region, for 17β-HSD1 function and tested the sensitivity towards sulfhydryl modifying chemicals. 3D structure modeling revealed important interactions of Cys10with residues involved in the stabilization of amino acids of the NADPH binding pocket. Analysis of enzyme activity revealed that 17β-HSD1 was irreversibly inhibited by the sulfhydryl modifying agents N-ethylmaleimide (NEM) and dithiocarbamates. Preincubation with increasing concentrations of NADPH protected 17β-HSD1 from inhibition by these chemicals. Cys10Ser mutant 17β-HSD1 was partially protected from inhibition by NEM and dithiocarbamates, emphasizing the importance of Cys10in the cofactor binding region. Substitution of Cys10with serine resulted in a decreased protein half-life, without significantly altering kinetic properties. Despite the fact that Cys10on 17β-HSD1 seems to have limited potential as a target for new enzyme inhibitors, the present study provides new insight into the structure-function relationships of this enzyme.

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Age-dependent biliary excretion of glutathione-related thiols in rats: role of gamma-glutamyltransferase

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1987.253.1.g86 ◽

1987 ◽

Vol 253 (1) ◽

pp. G86-G92 ◽

Cited By ~ 1

Author(s):

Z. Gregus ◽

A. F. Stein ◽

C. D. Klaassen

Keyword(s):

Postnatal Development ◽

Biliary Excretion ◽

Excretion Rate ◽

Dependent Manner ◽

Gamma Glutamyltransferase ◽

Hydrolysis Products ◽

Age Dependent ◽

Old Rats ◽

Hydrolysis Of

The role of gamma-glutamyltransferase (GGT) in the biliary excretion of glutathione (GS) was studied in rats during postnatal development. Between 2 and 10 wk of age the biliary excretion of GS-related sulfur increased ninefold. During this period, alterations were observed in both hepatic GGT and the composition of GS-related thiols and disulfides in bile. For instance, between 3 and 4 wk of age, GGT activity and the biliary excretion of GS hydrolysis products (Cys-Gly and Cys) increased markedly, and the latter became the predominant sulfhydryls in bile. However, by 10 wk of age, the excretion rate of GS increased and exceeded the rate of excretion of Cys-Gly and Cys. The parallelism between hepatic GGT activity and the biliary excretion of GS-hydrolysis products during development suggests a role for GGT in the formation of biliary Cys-Gly and Cys. Furthermore, in 4-wk-old rats, inhibition of hepatic GGT by acivicin markedly decreased the biliary excretion of Cys-Gly and Cys and increased that of GS without influencing the excretion of total GS-related sulfur in bile. The biliary excretion of GS-related thiols was less responsive to acivicin in 2- and 7- to 10-wk-old rats, suggesting that GGT plays a smaller role in influencing biliary thiol composition at those ages. In summary, GS transported into bile is hydrolyzed in an age-dependent manner, however, the GGT-initiated hydrolysis of GS does not affect the biliary excretion of total thiols in rats.

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Extracellular enzymatic activities in the aquatic ecosystems of the Danube Delta. 2. Alkaline phosphatase activity

ROMANIAN BIOTECHNOLOGICAL LETTERS ◽

10.25083/rbl/26.1/2269.2274 ◽

2021 ◽

Vol 26 (1) ◽

pp. 2269-2274

Author(s):

IOAN PĂCEŞILĂ ◽

EMILIA RADU

Keyword(s):

Alkaline Phosphatase ◽

Water Column ◽

Aquatic Ecosystems ◽

Temporal Dynamics ◽

Extracellular Enzyme ◽

Danube Delta ◽

Phytoplankton Communities ◽

Extracellular Enzymatic Activities ◽

Adjacent Channels ◽

Hydrolysis Of

Phosphorus is one of the most important inorganic nutrients in aquatic ecosystems, the development and functioning of the phytoplankton communities being often correlated with the degree of availability in assimilable forms of this element. Alkaline phosphatase (AP) is an extracellular enzyme with nonspecific activity that catalyses the hydrolysis of a large variety of organic phosphate esters and release orthophosphates. During 2011-2013, AP Activity (APA) was assessed in the water column and sediments of several aquatic ecosystems from Danube Delta: Roșu Lake, Mândra Lake and their adjacent channels – Roșu-Împuțita and Roșu-Puiu. The intensity of APA widely fluctuated, ranging between 230-2578 nmol p-nitrophenol L-1h-1 in the water column and 2104-15631 nmol p-nitrophenol g-1h-1 in sediment. Along the entire period of the study, APA was the most intense in Roșu-Împuțita channel, for both water and sediment samples. Temporal dynamics revealed its highest values in summer for the water column and in autumn for sediment. Statistical analysis showed significant seasonal diferences of the APA dynamics in spring vs. summer and autumn for the water column, and any relevant diferences for sediment.

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Hyperferritinaemia: An Iron Sword of Autoimmunity

Current Pharmaceutical Design ◽

10.2174/1381612825666190709202804 ◽

2019 ◽

Vol 25 (27) ◽

pp. 2909-2918 ◽

Cited By ~ 4

Author(s):

Joanna Giemza-Stokłosa ◽

Md. Asiful Islam ◽

Przemysław J. Kotyla

Keyword(s):

Immune Response ◽

Macrophage Activation ◽

Inflammatory Diseases ◽

Acute Phase Reactant ◽

Catastrophic Antiphospholipid Syndrome ◽

Inflammatory Conditions ◽

Phase Reactant ◽

Signalling Molecule ◽

Cytokine Synthesis

Background:: Ferritin is a molecule that plays many roles being the storage for iron, signalling molecule, and modulator of the immune response. Methods:: Different electronic databases were searched in a non-systematic way to find out the literature of interest. Results:: The level of ferritin rises in many inflammatory conditions including autoimmune disorders. However, in four inflammatory diseases (i.e., adult-onset Still’s diseases, macrophage activation syndrome, catastrophic antiphospholipid syndrome, and sepsis), high levels of ferritin are observed suggesting it as a remarkable biomarker and pathological involvement in these diseases. Acting as an acute phase reactant, ferritin is also involved in the cytokine-associated modulator of the immune response as well as a regulator of cytokine synthesis and release which are responsible for the inflammatory storm. Conclusion:: This review article presents updated information on the role of ferritin in inflammatory and autoimmune diseases with an emphasis on hyperferritinaemic syndrome.

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Role of a guanine nucleotide-binding regulatory protein in the hydrolysis of hepatocyte phosphatidylinositol 4,5-bisphosphate by calcium-mobilizing hormones and the control of cell calcium. Studies utilizing aluminum fluoride.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)38594-0 ◽

1985 ◽

Vol 260 (27) ◽

pp. 14477-14483 ◽

Cited By ~ 33

Author(s):

P F Blackmore ◽

S B Bocckino ◽

L E Waynick ◽

J H Exton

Keyword(s):

Regulatory Protein ◽

Nucleotide Binding ◽

Aluminum Fluoride ◽

Guanine Nucleotide ◽

Cell Calcium ◽

Guanine Nucleotide Binding ◽

Hydrolysis Of

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Cysteine-Rich Hydrophobin Gene Family: Genome Wide Analysis, Phylogeny and Transcript Profiling in Cordyceps militaris

International Journal of Molecular Sciences ◽

10.3390/ijms22020643 ◽

2021 ◽

Vol 22 (2) ◽

pp. 643

Author(s):

Xiao Li ◽

Fen Wang ◽

Yanyan Xu ◽

Guijun Liu ◽

Caihong Dong

Keyword(s):

Life Cycle ◽

Pathogenic Fungi ◽

Class Ii ◽

Cordyceps Militaris ◽

Transcript Profiling ◽

Saprotrophic Fungi ◽

Genome Wide Analysis ◽

Genome Wide ◽

Encoding Genes

Hydrophobins are a family of small secreted proteins found exclusively in fungi, and they play various roles in the life cycle. In the present study, genome wide analysis and transcript profiling of the hydrophobin family in Cordyceps militaris, a well-known edible and medicinal mushroom, were studied. The distribution of hydrophobins in ascomycetes with different lifestyles showed that pathogenic fungi had significantly more hydrophobins than saprotrophic fungi, and class II members accounted for the majority. Phylogenetic analysis of hydrophobin proteins from the species of Cordyceps s.l. indicated that there was more variability among the class II members than class I. Only a few hydrophobin-encoding genes evolved by duplication in Cordyceps s.l., which was inconsistent with the important role of gene duplication in basidiomycetes. Different transcript patterns of four hydrophobin-encoding genes during the life cycle indicated the possible different functions for each. The transcripts of Cmhyd2, 3 and 4 can respond to light and were related with the photoreceptors. CmQHYD, with four hydrophobin II domains, was first found in C. militaris, and multi-domain hydrophobins were only distributed in the species of Cordycipitaceae and Clavicipitaceae. These results could be helpful for further function research of hydrophobins and could provide valuable information for the evolution of hydrophobins.

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Steroid Sulphatase and Its Inhibitors: Past, Present and Future

Molecules ◽

10.3390/molecules26102852 ◽

2021 ◽

Vol 26 (10) ◽

pp. 2852

Author(s):

Paul A. Foster

Keyword(s):

Good Evidence ◽

The Past ◽

Steroid Sulphatase ◽

University Of Oxford ◽

Therapeutic Value ◽

Breast And Prostate Cancer ◽

The University ◽

Further Development ◽

Hydrolysis Of

Steroid sulphatase (STS), involved in the hydrolysis of steroid sulphates, plays an important role in the formation of both active oestrogens and androgens. Since these steroids significantly impact the proliferation of both oestrogen- and androgen-dependent cancers, many research groups over the past 30 years have designed and developed STS inhibitors. One of the main contributors to this field has been Prof. Barry Potter, previously at the University of Bath and now at the University of Oxford. Upon Prof. Potter’s imminent retirement, this review takes a look back at the work on STS inhibitors and their contribution to our understanding of sulphate biology and as potential therapeutic agents in hormone-dependent disease. A number of potent STS inhibitors have now been developed, one of which, Irosustat (STX64, 667Coumate, BN83495), remains the only one to have completed phase I/II clinical trials against numerous indications (breast, prostate, endometrial). These studies have provided new insights into the origins of androgens and oestrogens in women and men. In addition to the therapeutic role of STS inhibition in breast and prostate cancer, there is now good evidence to suggest they may also provide benefits in patients with colorectal and ovarian cancer, and in treating endometriosis. To explore the potential of STS inhibitors further, a number of second- and third-generation inhibitors have been developed, together with single molecules that possess aromatase–STS inhibitory properties. The further development of potent STS inhibitors will allow their potential therapeutic value to be explored in a variety of hormone-dependent cancers and possibly other non-oncological conditions.

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Regulation of the synthesis and hydrolysis of ATP by mitochondrial ATPase. Role of Mg2+.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)43969-x ◽

1983 ◽

Vol 258 (22) ◽

pp. 13673-13679 ◽

Cited By ~ 1

Author(s):

A Gómez-Puyou ◽

G Ayala ◽

U Muller ◽

M Tuena de Gómez-Puyou

Keyword(s):

Mitochondrial Atpase ◽

Hydrolysis Of

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Interactions of tervalent lanthanide ions with bacterial collagenase (clostridiopeptidase A)

Biochemical Journal ◽

10.1042/bj1950677 ◽

1981 ◽

Vol 195 (3) ◽

pp. 677-684 ◽

Cited By ~ 15

Author(s):

Christopher H. Evans

Keyword(s):

Ionic Radius ◽

Substrate Inhibition ◽

Volume Ratio ◽

Binding Pocket ◽

Lanthanide Ions ◽

Ionic Radii ◽

Apparent Dissociation Constant ◽

Substrate Complex ◽

Bacterial Collagenase ◽

Hydrolysis Of

Tervalent cations of the lanthanide (rare-earth) elements reversibly inhibit bacterial collagenase (clostridiopeptidase A; EC 3.4.24.3). Sm3+, whose ionic radius is closest to that of Ca2+, is the most effective inhibitor, completely suppressing clostridiopeptidase activity at a concentration of 100μm in the presence of 5mm-Ca2+. Er3+ and Lu3+, which both have ionic radii smaller than either Ca2+ or Sm3+, inhibit less efficiently, and La3+, which is slightly larger than Ca2+ or Sm3+, inhibits only weakly. These findings indicate a closely fitting, stereospecific, Ca2+-binding pocket in clostridiopeptidase, which excludes ions that are only slightly larger than Ca2+ [ionic radius 0.099nm (0.99 Ȧ)]. By contrast, trypsin, an enzyme whose activity does not depend on Ca2+, requires lanthanide concentrations 50–100-fold greater for inhibition. Furthermore, the relative efficiency of inhibition of trypsin by lanthanides increases as the lanthanide ions become smaller and the charge/volume ratio increases. At a concentration of 50μm, Sm3+ lowers the apparent Km for the hydrolysis of Pz-peptide by clostridiopeptidase from 5.4mm to 0.37mm and the apparent Vmax. from 0.29 Wünsch–Heidrich unit to 0.018 unit. Thus Sm3+ enhances the affinity of this enzyme for its substrate; inhibition of hydrolysis of Pz-peptide may result from the excessive stability of the enzyme–Sm3+–substrate complex. Inhibition by Sm3+ is competitive with regard to Ca2+. The apparent dissociation constant, Kd, of Ca2+ is 0.27mm, where the Ki for Sm3+ is 12μm. Clostridiopeptidase is more thermolabile in the absence of Ca2+. With Sm3+, thermoinactivation of the enzyme at 53°C or 60°C is initially accelerated, but then becomes retarded as heating continues. Lanthanide ions bind to gelatin and collagen. In so doing, they appear to protect these substrates from lysis by clostridiopeptidase through mechanisms additional to supplanting Ca2+ at its binding site on the enzyme. Collagen and gelatin sequester sufficient lanthanide ions to gain partial protection from clostridiopeptidase in the absence of an extraneous source of these inhibitors.

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