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Adav, S.S. (author), Li, A.A. (author), Manavalan, A. (author), Punt, P. (author), Sze, S.K. (author), TNO Kwaliteit van Leven (author)The natural lifestyle of Aspergillus niger made them more effective secretors of hydrolytic proteins and becomes critical when this species were exploited as hosts for the commercial secretion of heterologous proteins. The protein secretion profile of A. niger and its mutant at different pH was explored using iTRAQ-based quantitative proteomics...article 2010
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Koopman, F.W. (author), de Winde, J.H. (author), Ruijssenaars, H.J. (author), TNO Kwaliteit van Leven (author)The solvent-tolerant bacterium Pseudomonas putida S12 was engineered to efficiently utilize the C1 compounds methanol and formaldehyde as auxiliary substrate. The hps and phi genes of Bacillus brevis, encoding two key steps of the ribulose monophosphate (RuMP) pathway, were introduced to construct a pathway for the metabolism of the toxic...article 2009
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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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Steeneken, P.A.M. (author), Tas, A.C. (author), Woortman, A.J.J. (author), Sanders, P. (author), Mijland, P.J.H.C. (author), de Weijs, L.G.R. (author), TNO Kwaliteit van Leven (author)The effect of the granule structure on the methylation of starch was investigated by comparing the substitution patterns of potato starch methylated in granular suspension and in solution to DS 0.3. Substitution patterns were analyzed by successive digestion with α-amylase and amyloglucosidase, fractionation of the resulting malto...article 2008
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Ruijssenaars, H.J. (author), Sperling, E.M.G.M. (author), Wiegerinck, P.H.G. (author), Brands, F.T.L. (author), Wery, J. (author), de Bont, J.A.M. (author), TNO Kwaliteit van Leven (author)A steroid 15β-hydroxylating whole-cell solvent tolerant biocatalyst was constructed by expressing the Bacillus megaterium steroid hydroxylase CYP106A2 in the solvent tolerant Pseudomonas putida S12. Testosterone hydroxylation was improved by a factor 16 by co-expressing Fer, a putative Fe-S protein from Bacillus subtilis. In addition, the...article 2007
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Jeurissen, S.M.F. (author), Punt, A. (author), Boersma, M.G. (author), Bogaards, J.J.P. (author), Fiamegos, Y.C. (author), Schilter, B. (author), van Bladeren, P.J. (author), Cnubben, N.H.P. (author), Rietjens, I.M.C.M. (author), TNO Kwaliteit van Leven (author)Human cytochrome P450 enzymes involved in the bioactivation of estragole to its proximate carcinogen 1′-hydroxyestragole were identified and compared to the enzymes of importance for 1′-hydroxylation of the related alkenylbenzenes methyleugenol and safrole. Incubations with Supersomes revealed that all enzymes tested, except P450 2C8, are...article 2007
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Goosen, C. (author), Yuan, X.L. (author), van Munster, J.M. (author), Ram, A.F.J. (author), van der Maarel, M.J.E.C. (author), Dijkhuizen, L. (author), TNO Kwaliteit van Leven (author)A novel subfamily of putative intracellular invertase enzymes (glycoside hydrolase family 32) has previously been identified in fungal genomes. Here, we report phylogenetic, molecular, and biochemical characteristics of SucB, one of two novel intracellular invertases identified in Aspergillus niger. The sucB gene was expressed in Escherichia...article 2007
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Jeurissen, S.M.F. (author), Bogaards, J.J.P. (author), Boersma, M.G. (author), ter Horst, J.P.F. (author), Awad, H.M. (author), Fiamegos, Y.C. (author), van Beek, T.A. (author), Alink, G.M. (author), Sudhölter, E.J.R. (author), Cnubben, N.H.P. (author), Rietjens, I.M.C.M. (author), TNO Kwaliteit van Leven (author)In vitro studies were performed to elucidate the human cytochrome P450 enzymes involved in the bioactivation of methyleugenol to its proximate carcinogen 1′-hydroxymethyleugenol. Incubations with Supersomes, expressing individual P450 enzymes to a high level, revealed that P450 1A2, 2A6, 2C9, 2C19, and 2D6 are intrinsically able to 1′...article 2006
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TNO Kwaliteit van Leven TNO Voeding (author), Ozimek, L.K. (author), Kralj, S. (author), Kaper, T. (author), van der Maarel, M.J.E.C. (author), Dijkhuizen, L. (author)Bacterial fructansucrase enzymes belong to glycoside hydrolase family 68 and catalyze transglycosylation reactions with sucrose, resulting in the synthesis of fructooligosaccharides and/or a fructan polymer. Significant differences in fructansucrase enzyme product specificities can be observed, i.e. in the type of polymer (levan or inulin)...article 2006
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Zuurmond, A.M. (author), Slot van der-Verhoeven, A.J. (author), van Dura, E.A. (author), de Groot, J. (author), Bank, R.A. (author), TNO Kwaliteit van Leven (author)Collagen deposits in fibrotic lesions often display elevated levels of hydroxyallysine (pyridinoline) cross-links. The relation between the occurrence of pyridinoline cross-links and the irreversibility of fibrosis suggests that these cross-links contribute to the aberrant accumulation of collagen. Based on its inhibitory effect on lysyl...article 2005
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Jeurissen, S.M.F. (author), Bogaards, J.J.P. (author), Awad, H.M. (author), Boersma, M.G. (author), Brand, W. (author), Fiamegos, Y.C. (author), van Beek, T.A. (author), Alink, G.M. (author), Sudhölter, E.J.R. (author), Cnubben, N.H.P. (author), Rietjens, I.M.C.M. (author), TNO Voeding (author)In the present study, the cytochrome P450 mediated bioactivation of safrole to its proximate carcinogenic metabolite, 1′-hydroxysafrole, has been investigated for the purpose of identifying the human P450 enzymes involved. The 1′-hydroxylation of safrole was characterized in a variety of in vitro test systems, including Supersomes, expressing...article 2004
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van der Maarel, M.J.E.C. (author), van der Veen, B. (author), Uitdehaag, J.C.M. (author), Leemhuis, H. (author), Dijkhuizen, L. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)Starch is a major storage product of many economically important crops such as wheat, rice, maize, tapioca, and potato. A large-scale starch processing industry has emerged in the last century. In the past decades, we have seen a shift from the acid hydrolysis of starch to the use of starch-converting enzymes in the production of maltodextrin,...article 2002
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TNO Voeding (author), te Biesebeke, R. (author), Krab, I.M. (author), Parmeggiani, A. (author)In this work, we have studied the role of the arginine finger region in determining the specificity of the GTPase activating proteins (GAPs) Saccharomyces cerevisiae Ira2p and human p120-GAP toward yeast Ras2p and human Ha-Ras p21. It is known that p120-GAP can enhance both Ras2p and Ha-Ras GTPase activities, whereas Ira2p is strictly specific...article 2001
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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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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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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
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Somers, W.A.C. (author), Stigter, E.C.A. (author), van Hartingsveldt, W. (author), van der Lugt, J.P. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)Quinohaemoprotein alcohol dehydrogenase from Comamonas testosteroni was co-immobilized with a redox polymer (a poly(vinylpyridine) complex functionalized with osmium bis(bipyridine) chloride) on an electrode. The enzyme electrode readily oxidizes primary alcohols and secondary alcohols with maximum current densities varying between 0.43 and 0.98...article 1998
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Overhand, M. (author), Stuivenberg, H.R. (author), Pieterman, E. (author), Cohen, L.H. (author), van Leeuwen, R.E.W. (author), Valentijn, A.R.P.M. (author), Overkleeft, H.S. (author), van der Marel, G.A. (author), van Boom, J.H. (author), Gaubius Instituut TNO (author)Novel diphosphonate homologs 7a-7c, and their cyclic counterparts 8a- 8c, of the previously synthesized farnesyl pyrophosphate analogs 1 and 2 were prepared and tested for their inhibition potency and specificity of the enzymes PFT and PGGT-I. Compound 2 was shown to be the most potent inhibitor of PFT (1C50=0.58 ± 0.45 μM) in this series. The...article 1998
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Holtman, W.L. (author), Vredenbregt-Heistek, J.C. (author), Schmitt, N.F. (author), Feussner, I. (author), Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author)Besides the pre-existing lipoxygenase (LOX-1) present in quiescent grains, a new lipoxygenase (LOX-2) is induced in embryos of germinating barley [Holtman, W. L., Van Duijn, G., Sedee, N. J. A. and Douma, A. C. (1996) Plant Physiol. 111, 569-576]. The fact that LOX-1 and LOX-2 form different products after incubation with linoleic acid, the (9S)...article 1997
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van der Aar, E.M. (author), Buikema, D. (author), Commandeur, J.N.M. (author), te Koppele, J.M. (author), van Ommen, B. (author), van Bladeren, P.J. (author), Vermeulen, N.P.E. (author), Leiden/Amsterdam Ctr. for Drug Res., Department of Pharmacochemistry, Vrije Universiteit, De Boelelaan 1083, 1081 HV, Amsterdam, Netherlands TNO Preventie en Gezondheid TNO Voeding (author)1. Four different rat glutathione S-transferase (GST) isoenzymes, belonging to three different classes, were examined for their GSH conjugating capacity towards 11 2-substituted 1-chloro-4-nitrobenzene derivatives. Significant differences were found in their enzyme kinetic parameters K(m), k(cat) and k(cat)/K(m). 2. Substrates with bulky...article 1996
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