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Exo-inulinase of Aspergillus niger N402: A hydrolytic enzyme with significant transfructosylating activity

Goosen, C. (author), van der Maarel, M.J.E.C. (author), Dijkhuizen, L. (author), TNO Kwaliteit van Leven (author)

The purified exo-inulinase enzyme of Aspergillus niger N402 (AngInuE; heterologously expressed in Escherichia coli) displayed a sucrose:inulin (S/I) hydrolysis ratio of 2.3, characteristic for a typical exo-inulinase. The enzyme also had significant transfructosylating activity with increasing sucrose concentrations, producing various...

article 2008

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Eradication of Helicobacter pylori infection favourably affects altered gastric mucosal MMP-9 levels

Kubben, F.J.G.M. (author), Sier, C.F.M. (author), Schram, M. (author), Witte, T.A.M.C. (author), Veenendaal, R.A. (author), van Duijn, W. (author), Verheijen, J.H. (author), Hanemaaijer, R. (author), Lamers, C.B.H.W. (author), Verspaget, H.W. (author), TNO Kwaliteit van Leven (author)

Background: Helicobacter pylori gastritis is recognized as an important pathogenetic factor in peptic ulcer disease and gastric carcinogenesis, and is accompanied by strongly enhanced gastric mucosal matrix metalloproteinase-9 (MMP-9) levels. Aim: This study was performed to investigate whether H. pylori-affected gastric mucosal MMP-2 and MMP-9...

article 2007

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Phylogenetic and biochemical characterization of a novel cluster of intracellular fungal α-amylase enzymes

van der Kaaij, R.M. (author), Janeček, Š. (author), van der Maarel, M.J.E.C. (author), Dijkhuizen, L. (author), TNO Kwaliteit van Leven (author)

Currently known fungal α-amylases are well-characterized extracellular enzymes that are classified into glycoside hydrolase subfamily GH13_1. This study describes the identification, and phylogenetic and biochemical analysis of novel intracellular fungal α-amylases. The phylogenetic analysis shows that they cluster in the recently identified...

article 2007

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Kinetic characteristics of acidic and alkaline ceramidase in human epidermis

Houben, E. (author), Uchida, Y. (author), Nieuwenhuizen, W.F. (author), de Paepe, K. (author), Vanhaecke, T. (author), Holleran, W.M. (author), Rogiers, V. (author), TNO Kwaliteit van Leven (author)

It has recently become evident that at least five ceramidase (CDase) isoforms are present in human epidermis, and that specifically acidic CDase (aCDase) and alkaline CDase (alkCDase) activities increase during keratinocyte differentiation, and thus might play a pivotal role(s) in permeability barrier function. Prior to investigating their...

article 2007

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Biochemical and functional modulation of the cartilage collagen network by IGF1, TGFβ2 and FGF2

Jenniskens, Y.M. (author), Koevoet, W. (author), de Bart, A.C.W. (author), Weinans, H. (author), Jahr, H. (author), Verhaar, J.A.N. (author), de Groot, J. (author), van Osch, G.J.V.M. (author), TNO Kwaliteit van Leven (author)

Objective: Examine effects of insulin-like growth factor 1 (IGF1), transforming growth factor β2 (TGFβ2) and fibroblast growth factor 2 (FGF2) on proteoglycan and collagen network and biomechanical properties of the newly formed cartilage matrix. Methods: Bovine articular chondrocytes were cultured in alginate beads for 3 weeks with or without...

article 2006

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Matrix metalloproteinase-2 is a consistent prognostic factor in gastric cancer

TNO Kwaliteit van Leven (author), Kubben, F.J.G.M. (author), Sier, C.F.M. (author), van Duijn, W. (author), Griffioen, G. (author), Hanemaaijer, R. (author), van de Velde, C.J.H. (author), van Krieken, J.H.J.M. (author), Lamers, C.B.H.W. (author), Verspaget, H.W. (author)

In a pioneer study, we showed 10 years ago that enhanced tissue levels of the matrix metalloproteinases (MMPs) MMP-2 and MMP-9 in gastric cancers, as determined by zymography, were related with worse overall survival of the patients. To corroborate these observations, we now assessed MMP-2 and MMP-9 with new techniques in an expanded group of...

article 2006

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Biochemical and molecular characterization of Lactobacillus reuteri 121 reuteransucrase

Kralj, S. (author), van Geel-Schutten, G.H. (author), van der Maarel, M.J.E.C. (author), Dijkhuizen, L. (author), TNO Voeding Centraal Instituut voor Voedingsonderzoek TNO (author)

Lactobacillus reuteri strain 121 uses sucrose for synthesis of a unique, soluble glucan ('reuteran') with mainly α-(1→4) glucosidic linkages. The gene (gtfA) encoding this glucansucrase enzyme had previously been characterized. Here, a detailed biochemical and molecular analysis of the GTFA enzyme is presented. This is believed to be the first...

article 2004

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Glucan synthesis in the genus Lactobacillus: Isolation and characterization of glucansucrase genes, enzymes and glucan products from six different strains

Kralj, S. (author), van Geel-Schutten, G.H. (author), Dondorff, M.M.G. (author), Kirsanovs, S. (author), van der Maarel, M.J.E.C. (author), Dijkhuizen, L. (author), TNO Voeding Centraal Instituut voor Voedingsonderzoek TNO (author)

Members of the genera Streptococcus and Leuconostoc synthesize various α-glucans (dextran, alternan and mutan). In Lactobacillus, until now, the only glucosyltransferase (GTF) enzyme that has been characterized is gtfA of Lactobacillus reuteri 121, the first GTF enzyme synthesizing a glucan (reuteran) that contains mainly α-(1 → 4) linkages...

article 2004

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Natural and recombinant fungal laccases for paper pulp bleaching

Sigoillot, C. (author), Record, E. (author), Belle, V. (author), Robert, J.L. (author), Levasseur, A. (author), Punt, P.J. (author), van den Hondel, C.A.M.J.J. (author), Fournel, A. (author), Sigoillot, J.C. (author), Asther, M. (author), TNO Voeding (author)

Three laccases, a natural form and two recombinant forms obtained from two different expression hosts, were characterized and compared for paper pulp bleaching. Laccase from Pycnoporus cinnabarinus, a well known lignolytic fungus, was selected as a reference for this study. The corresponding recombinant laccases were produced in Aspergillus...

article 2004

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Association between thrombin activatable fibrinolysis inhibitor genotype and levels in plasma: Comparison of different assays

Guimarães, A.H.C. (author), van Tilburg, N.H. (author), Vos, H.L. (author), Bertina, R.M. (author), Rijken, D.C. (author)

Thrombin activatable fibrinolysis inhibitor (TAFI) antigen levels exhibit a large interindividual variability in which genetic control seems to play a major role. However, recent reports have questioned the association between TAFI concentration and genotype, suggesting that variable antibody reactivity towards TAFI isoforms, particularly the...

article 2004

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Acetoxy drug: Protein transacetylase of buffalo liver - Characterization and mass spectrometry of the acetylated protein product

Kohli, E. (author), Gaspari, M. (author), Raj, H.G. (author), Parmar, V.S. (author), Sharma, S.K. (author), van der Greef, J. (author), Kumari, R. (author), Gupta, G. (author), Khurana, P. (author), Tyagi, Y.K. (author), Watterson, A.C. (author), Olsen, C.E. (author), TNO Voeding (author)

The purification and characterization of the buffalo liver microsomal transacetylase (TAase) catalyzing the transfer of acetyl groups from a model acetoxy drug: 7,8-diacetoxy-4-methylcoumarin (DAMC) to GST3-3 has been described here. The enzyme was routinely assayed using DAMC and cytosolic GST as the substrates and was partially purified from...

article 2004

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Efficient production of Arthromyces ramosus peroxidase by Aspergillus awamori

Lokman, B.C. (author), Joosten, V. (author), Hovenkamp, J. (author), Gouka, R.J. (author), Verrips, C.T. (author), van den Hondel, C.A.M.J.J. (author)

The heterologous production of Arthromyces ramosus peroxidase (ARP) was analysed in the filamentous fungus Aspergillus awamori under control of the inducible endoxylanase promoter. Secretion of active ARP was achieved up to 800 mg l-1 in shake flask cultures. Western blot analysis showed that an rARP product of the correct molecular weight was...

article 2003

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Identification of PLOD2 as Telopeptide Lysyl Hydroxylase, an Important Enzyme in Fibrosis

TNO Preventie en Gezondheid (author), van der Slot, A.J. (author), Zuurmond, A.M. (author), Bardoel, A.F.J. (author), Wijmenga, C. (author), Pruijs, H.E.H. (author), Sillence, D.O. (author), Brinckmann, J. (author), Abraham, D.J. (author), Black, C.M. (author), Verzijl, N. (author), de Groot, J. (author), Hanemaaijer, R. (author), te Koppele, J.M. (author), Huizinga, T.W.J. (author), Bank, R.A. (author)

The hallmark of fibrotic processes is an excessive accumulation of collagen. The deposited collagen shows an increase in pyridinoline cross-links, which are derived from hydroxylated lysine residues within the telopeptides. This change in cross-linking is related to irreversible accumulation of collagen in fibrotic tissues. The increase in...

article 2003

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Oral, but not transdermal, administration of estrogens lowers tissue- type plasminogen activator levels in humans without affecting endothelial synthesis

Giltay, E.J. (author), Gooren, L.J.G. (author), Emeis, J.J. (author), Kooistra, T. (author), Stehouwer, C.D.A. (author), TNO Preventie en Gezondheid (author)

Oral estrogen administration decreases plasma levels of tissue-type plasminogen activator (tPA), which may be explained by a decrease in endothelial tPA synthesis, an increase in its hepatic clearance, or both. In the present study, we determined (1) differences between oral (ie, via the liver) ethinyl estradiol and transdermal (ie, systemic)...

article 2000

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Purification and characterization of a Baeyer-Villiger mono-oxygenase from Rhodococcus erythropolis DCL14 involved in three different monocyclic monoterpene degradation pathways

van der Werf, M.J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

A Baeyer-Villiger mono-oxygenase (BVMO), catalysing the NADPH- and oxygen-dependent oxidation of the monocyclic monoterpene ketones 1-hydroxy-2-oxolimonene, dihydrocarvone and menthone, was purified to homogeneity from Rhodococcus erythropolis DCL14. Monocyclic monoterpene ketone mono-oxygenase (MMKMO) is a monomeric enzyme of molecular mass 60...

article 2000

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Regulation of expression of the Aspergillus niger benzoate para-hydroxylase cytochrome P450 system

van den Brink, J.M. (author), Punt, P.J. (author), van Gorcom, R.F.M. (author), van den Hondel, C.A.M.J.J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

Cytochrome P450 enzyme systems are found throughout nature and are involved in many different, often complex, bioconversions. In the endoplasmic reticulum of the filamentous fungus Aspergillus niger a cytochrome P450 enzyme system is present that is capable of the para-hydroxylation of benzoate. The expression of the two genes encoding the...

article 2000

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Characterization of a foldase, protein disulfide isomerase A, in the protein secretory pathway of Aspergillus niger

Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author), Ngiam, C. (author), Jeenes, D.J. (author), Punt, P.J. (author), van den Hondel, C.A.M.J.J. (author), Archer, D.B. (author)

Protein disulfide isomerase (PDI) is important in assisting the folding and maturation of secretory proteins in eukaryotes. A gene, pdiA, encoding PDIA was previously isolated from Aspergillus niger, and we report its functional characterization here. Functional analysis of PDIA showed that it catalyzes the refolding of denatured and reduced...

article 2000

document

Acid-catalyzed enzymatic hydrolysis of 1-methylcyclohexene oxide

van der Werf, M.J. (author), de Bont, J.A.M. (author), Swarts, H.J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

Limonene-1,2-epoxide hydrolase from Rhodococcus erythropolis DCL14, an enzyme involved in the limonene metabolism of this microorganism, catalyzes the enantioselective hydrolysis of 1-methylcyclohexene oxide. (1R,2S)-1- Methylcyclohexene oxide was the preferred substrate and it was mainly hydrolyzed to (1S,2S)-1-methylcyclohexane-1,2-diol, while...

article 1999

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Exploring the active center of human acetylcholinesterase with stereomers of an organophosphorus inhibitor with two chiral centers

Ordentlich, A. (author), Barak, D. (author), Kronman, C. (author), Benschop, H.P. (author), de Jong, L.P.A. (author), Ariel, N. (author), Barak, R. (author), Segall, Y. (author), Velan, B. (author), Shafferman, A. (author)

The stereoselectivity of the phosphonylation reaction and the effects of adduct configuration on the aging process were examined for human acetylcholinesterase (HuAChE) and its selected active center mutants, using the four stereomers of 1,2,2-trimethylpropyl methylphosphonofluoridate (soman). The reactivity of wild type HuAChE toward the P(S)...

article 1999

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Comparison of immunoaffinity chromatography enrichment and nuclease P1 procedures for 32P-postlabelling analysis of PAH- DNA adducts

Randerath, K. (author), Sriram, P. (author), Moorthy, B. (author), Aston, J.P. (author), Baan, R.A. (author), van den Berg, P.T.M. (author), Booth, E.D. (author), Watson, W.P. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

32P-postlabelling analysis for detecting DNA adducts formed by polycyclic aromatic compounds is one of the most widely used techniques for assessing genotoxicity associated with these compounds. In cases where the formation of adducts is extremely low, a crucial step in the analysis is an enrichment procedure for adducts prior to the...

article 1998