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Improved proteolytic stability of chicken cathelicidin-2 derived peptides by d-amino acid substitutions and cyclization

Molhoek, E.M. (author), van Dijk, A. (author), Veldhuizen, E.J.A. (author), Haagsman, H.P. (author), Bikker, F.J. (author)

A truncated version of host defense peptide chicken cathelicidin-2, C1-15, possesses potent, broad spectrum antibacterial activity. A variant of this peptide, F2,5,12W, which contains 3 phenylalanine to tryptophan substitutions, possesses improved antibacterial activity and lipopolysaccharide (LPS) neutralizing activity compared to C1-15. In...

article 2011

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Transcriptome analysis of a phenol-producing Pseudomonas putida S12 construct: Genetic and physiological basis for improved production

Wierckx, N.J.P. (author), Ballerstedt, H. (author), de Bont, J.A.M. (author), de Winde, J.H. (author), Ruijssenaars, H.J. (author), Wery, J. (author), TNO Kwaliteit van Leven (author)

The unknown genetic basis for improved phenol production by a recombinant Pseudomonas putida S12 derivative bearing the tpl (tyrosine-phenol lyase) gene was investigated via comparative transcriptomics, nucleotide sequence analysis, and targeted gene disruption. We show upregulation of tyrosine biosynthetic genes and possibly decreased...

article 2008

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Evening dietary tryptophan improves post-sleep behavioral and brain measures of memory function in healthy subjects

Markus, C.R. (author), Jonkman, L.M. (author), Lammers, J.H.C.M. (author), Deutz, N.E.P. (author), TNO Kwaliteit van Leven (author)

Brain serotonin function has been implicated in the control of sleep and sleep related memory dysfunctions are attributed to deficient brain serotonin activity. Depletion of the serotonin precursor tryptophan reduces brain serotonin function and is found to cause sleep abnormalities and cognitive decline. We hypothesized that enhancing pre-sleep...

article 2006

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Single amino acid residue changes in subsite - 1 of inulosucrase from Lactobacillus reuteri 121 strongly influence the size of products synthesized

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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Evening intake of α-lactalbumin increases plasma tryptophan availability and improves morning alertness and brain measures of attention

Markus, C.R. (author), Jonkman, L.M. (author), Lammers, J.H.C.M. (author), Deutz, N.E.P. (author), Messer, M.H. (author), Rigtering, N. (author), TNO Kwaliteit van Leven TNO Voeding (author)

Background: Brain serotonin function is thought to promote sleep regulation and cognitive processes, whereas sleep abnormalities and subsequent behavioral decline are often attributed to deficient brain serotonin activity. Brain uptake of the serotonin precursor tryptophan is dependent on nutrients that influence the availability of tryptophan...

article 2005

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Identification of pitfalls in the analysis of heat capacity changes of β-lactoglobulin A

van Teeffelen, A.M.M. (author), Meinders, M.B.J. (author), de Jongh, H.H.J. (author), TNO Kwaliteit van Leven (author)

Information on changes in heat capacity (ΔCp) of proteins upon unfolding is used frequently in literature to understand possible follow-up reactions of protein denaturation, like their aggregation propensity. This thermodynamic property is intrinsic to the protein's architecture and unfolding and should be independent of the approach used to...

article 2005

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Generation of a recombinant apolipoprotein E variant with improved biological functions: Hydrophobic residues (LEU-261, TRP-264, PHE-265, LEU-268, VAL-269) of apoE can account for the apoE-induced hypertriglyceridemia

TNO Kwaliteit van Leven (author), Kypreos, K.E. (author), van Dijk, K.W. (author), Havekes, L.M. (author), Zannis, V.I. (author)

To identify the residues in the carboxyl-terminal region 260-299 of human apolipoprotein E (apoE) that contribute to hypertriglyceridemia, two sets of conserved, hydrophobic amino acids between residues 261 and 283 were mutated to alanines, and recombinant adenoviruses expressing these apoE mutants were generated. Adenovirus-mediated gene...

article 2005

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Bioavailability of tryptophan from a single oral dose of a trytophan-enriched peptide mixture in healthy men

Brink, E.J. (author), Boelsma, E. (author), Steijns, J. (author), Hendriks, H.F.J. (author), TNO Voeding Centraal Instituut voor Voedingsonderzoek TNO (author)

The aim of the study was to investigate the bioavailability of tryptophan (Trp) from a Trp-enriched peptide mixture in healthy men. A second objective was to investigate the effect of this Trp-enriched protein hydrolysate on potential parameters of serotonergic activity. serum serotonim melatonin and prolactin and urinary 5-hydroxyindol-acetic...

article 2004

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Moderate whisky consumption in combination with an evening meal reduces tryptophan availability to the brain but does not influence performance in healthy volunteers

TNO Voeding Centraal Instituut voor Voedingsonderzoek TNO (author), Markus, C.R. (author), Sierksma, A. (author), Verbeek, C. (author), van Rooijen, J.J.M. (author), Patel, H.J. (author), Brand, A.N. (author), Hendriks, H.F.J. (author)

Brain serotonin (5-HT) synthesis is controlled by nutrients that influence the availability of plasma tryptophan (Trp) as compared with the sum of the other large neutral amino acids (LNAA; Trp:LNAA). Alcohol consumption is found to change mood and performance and this might well be due to alterations in the plasma Trp:LNAA ratio and brain 5-HT....

article 2004

document

Chemical processing as a tool to generate ovalbumin variants with changed stability

Kosters, H.A. (author), Broersen, K. (author), de Groot, J. (author), Simons, J.W.F.A. (author), Wierenga, P. (author), de Jongh, H.H.J. (author), TNO Voeding (author)

Processing of ovalbumin may result in proteins that differ more than 23°C in denaturation temperature while the structural fold is not significantly affected. This is achieved by 1) conversion of positive residues into negative ones (succinylation); 2) elimination of negative charges (methylation); 3) reducing the proteins hydrophobic exposure ...

article 2003

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Effect of heat-induced aggregation on the IgE binding of patatin (Sol t 1) is dominated by other potato proteins

Koppelman, S.J. (author), van Koningsveld, G.A. (author), Knulst, A.C. (author), Gruppen, H. (author), Pigmans, I.G.A.J. (author), de Jongh, H.H.J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

The interaction of the major potato allergen patatin, Sol t 1, with IgE was investigated on a quantitative level as a function of heat treatment at different temperatures. On the basis of a number of publications, potato is considered to be a heat-labile allergen, but the molecular explanation for this behavior was not given. In this work, heat...

article 2002

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Dose-dependent effect of alpha-lactalbumin in combination with two different doses of glucose on the plasma Trp/LNAA ratio

Markus, C.R. (author), Klöpping-Ketelaars, W.I. (author), Pasman, W. (author), Klarenbeek, B. (author), van den Berg, H. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

A deficient brain serotonin function has been demonstrated in psychiatric disorders and increases in brain serotonin ameliorate emotional and behavioural abnormalities found in depression. The uptake of the serotonin precursor tryptophan into the brain is dependent on nutrients that influence the cerebral availability of tryptophan via a change...

article 2000

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The bovine protein -lactalbumin increases the plasma ratio of tryptophan to the other large neutral amino acids and in vulnerable subjects raises brain serotonin activity reduces cortisol concentration and improves mood under stress

Centraal Instituut voor Voedingsonderzoek TNO (author), Markus, C.R. (author), Olivier, B. (author), Panhuysen, G.E.M. (author), van der Gugten, J. (author), Alles, M.S. (author), Tuiten, A. (author), Westenberg, H.G.M. (author), Fekkes, D. (author), Koppeschaar, H.F. (author), de Haan, E.E.H.F. (author)

Background: Increased brain serotonin may improve the ability to cope with stress, whereas a decline in serotonin activity is involved in depressive mood. The uptake of the serotonin precursor, tryptophan, into the brain is dependent on nutrients that influence the cerebral availability of tryptophan via a change in the ratio of plasma...

article 2000

document

Carbohydrate intake improves cognitive performance of stress-prone individuals under controllable laboratory stress

Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author), Markus, C.R. (author), Panhuysen, G. (author), Jonkman, L.M. (author), Bachman, M. (author)

Cognitive performance has been found to decline after exposure to stress, particularly in stress-prone subjects. The present study investigated whether a carbohydrate-rich, protein-poor (CR/PP) diet, which may enhance cerebral serotonin function in stress-prone subjects due to increases in the available tryptophan, improves the performance of...

article 1999

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Heat-induced conformational changes of patatin, the major potato tuber protein

Pots, A.M. (author), de Jongh, H.H.J. (author), Gruppen, H. (author), Hamer, R.J. (author), Voragen, A.G.J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

This paper presents a first structural characterization of isolated patatin, the major potato tuber protein, at ambient and elevated temperatures. Isolated patatin at room temperature is a highly structured molecule at both secondary and tertiary levels. It is estimated from far-ultraviolet circular dichroism data that about 33% of the residues...

article 1998

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Nucleotide sequence of the Aspergillus niger trpC gene: Structural relationship with analogous genes of other organisms

Medisch Biologisch Laboratorium TNO (author), Kos, T. (author), Kuijvenhoven, A. (author), Hessing, H.G.M. (author), Pouwels, P.H. (author), van den Hondel, C.A.M.J.J. (author)

Molecular Sequence Numbers: GENBANK: X07071; Chemicals/CAS: tryptophan, 6912-86-3, 73-22-3; DNA Restriction Enzymes, EC 3.1.21; Tryptophan, 73-22-3

article 1988

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Vitamin B6 status of women suffering from premenstrual syndrome

van den Berg, H. (author), Louwerse, E.S. (author), Bruinse, H.W. (author), Thissen, J.T.N.M. (author), Schrijver, J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

The vitamin B6 status of women suffering from premenstrual symptoms (PMS, n = 19) and a group of matched controls (n = 19) has been investigated. The women volunteering in the study were selected on strictly defined criteria. Several biochemical parameters of the metabolism of vitamin B6 and tryptophan were studied in blood and urine samples...

article 1986

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The construction of new vehicles for the cloning of transcription termination signals

Enger-Valk, B.E. (author), van Rotterdam, J. (author), Pouwels, P.H. (author), Medisch Biologisch Laboratorium TNO (author)

Chemicals/CAS: DNA Restriction Enzymes, EC 3.1.21; DNA, Recombinant; Plasmids; Tryptophan, 73-22-3

article 1981

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Escherichia coli mutant strain with altered expression of the tryptophan operon: Isolation and preliminary characterization

Pouwels, P.H. (author), Scholten, H.J. (author), Medisch Biologisch Laboratorium TNO (author)

Chemicals/CAS: tryptophan, 6912-86-3, 73-22-3; Anthranilate Synthase, EC 4.1.3.27; Lactose, 63-42-3; RNA, Bacterial; RNA, Messenger; Tryptophan Synthase, EC 4.2.1.20; Tryptophan, 73-22-3

article 1979

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Escherichia coli mutant strain with altered expression of the tryptophan operon: Ribonucleic acid synthesis in vitro

Pouwels, P.H. (author), de Groot, G.P. (author), Medisch Biologisch Laboratorium TNO (author)

Chemicals/CAS: tryptophan, 6912-86-3, 73-22-3; Antibiotics, Aminoglycoside; DNA-Directed RNA Polymerases, EC 2.7.7.6; Heparin, 9005-49-6; Rifampin, 13292-46-1; RNA, Bacterial; Tryptophan, 73-22-3

article 1979