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Boers, M.N. (author), de Klerk, W.P.C. (author), TNO Defensie en Veiligheid (author)A lifetime prediction study is carried out on four triple base propellant compositions by artificial ageing. The ageing effects are studied with High Performance Liquid Chromatography (HPLC) and Heat Flow Calorimetry (HFC) in order to find the most effective stabilizer and to evaluate the advantages and disadvantages of both methods. It is...article 2005
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van der Veen, M. (author), Norde, W. (author), Stuart, M.C. (author)The influence of succinylation on lysozyme is studied using circular dichroism, fluorescence spectroscopy, and differential scanning calorimetry. The spectroscopic data reveal that at room temperature the structures of succinylated lysozyme and native lysozyme are similar. However, the calorimetric results show that the thermal stability of...article 2005
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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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van Teeffelen, A.M.M. (author), Broersen, K. (author), de Jongh, H.H.J. (author), TNO Kwaliteit van Leven (author)Chemical glycosylation of proteins occurs in vivo spontaneously, especially under stress conditions, and has been linked in a number of cases to diseases related to protein denaturation and aggregation. It is the aim of this work to study the origin of the change in thermodynamic properties due to glucosylation of the folded β-lactoglobulin A....article 2005
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TNO Defensie en Veiligheid (author), Kersten, R.J.A. (author), Boers, M.N. (author), Stork, M.M. (author), Visser, C. (author)The results of a Round-Robin test on the decomposition reaction of 15% w/w di-tertiary-butyl peroxide (DTBP) in toluene are described in the present paper. The aim of the Round-Robin test was to compare the results of different (pseudo-)adiabatic reaction calorimeters in terms of accuracy and reliability for practical applications. The...article 2005
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Characterization of Pea Vicilin. 1. Denoting Convicilin as the α-Subunit of the Pisum Vicilin FamilyO'Kane, F.E. (author), Happe, R.P. (author), Vereijken, J.M. (author), Gruppen, H. (author), van Boekel, M.A.J.S. (author), TNO Voeding Centraal Instituut voor Voedingsonderzoek TNO (author)Vicilin, a major globulin protein of pea that has been described as "extremely heterogeneous in terms of its polypeptide composition", was extracted from pea flour under alkaline conditions and subsequently fractionated by salt under acid conditions. This procedure induced the separation of vicilin into two fractions, which, after purification,...article 2004
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Trofimova, D. (author), de Jongh, H.H.J. (author), TNO Voeding (author)Maillard products of β-lactoglobulin (βLg) and fructose oligosaccharide (FOS) were obtained in different degrees of modification depending on incubation time and pH. By use of a variety of biochemical and spectroscopic tools, it was demonstrated that the modification at limited degrees does not significantly affect the secondary, tertiary, and...article 2004
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Centraal Instituut voor Voedingsonderzoek TNO (author), Pouvreau, L. (author), Gruppen, H. (author), van Koningsveld, G.A. (author), van den Broek, L.A.M. (author), Voragen, A.G.J. (author)Potato serine protease inhibitor (PSPI) is the most abundant protease inhibitor group in potato tuber. The investigated PSPI isoforms have a highly similar structure at both the secondary and the tertiary level. From the results described, PSPI is classified as a β-II protein based on (1) the presence in the near-UV spectra of sharp peaks,...article 2004
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TNO Zeist (author), van den Broek, L.A.M. (author), Pouvreau, L. (author), Lommerse, G. (author), Schipper, B. (author), van Koningsveld, G.A. (author), Gruppen, H. (author)In the present study the structural properties of potato protease inhibitor 1 (PI-1) were studied as a function of temperature to elucidate its precipitation mechanism upon heating. A cDNA coding for PI-1 from cv. Bintje was cloned and expressed in Pichia pastoris. Using the recombinant PI-1 it was suggested that PI-1 behaves as a hexameric...article 2004
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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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Koppelman, S.J. (author), Knol, E.F. (author), Vlooswijk, R.A.A. (author), Wensing, M. (author), Knulst, A.C. (author), Hefle, S.L. (author), Gruppen, H. (author), Piersma, S. (author)Background: Peanut allergen Ara h 3 has been the subject of investigation for the last few years. The reported data strongly depend on recombinant Ara h 3, since a purification protocol for Ara h 3 from peanuts was not available. Methods: Peanut allergen Ara h 3 (glycinin), was purified and its posttranslational processing was investigated. Its...article 2003
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de Klerk, W.P.C. (author), van Driel, C.A. (author), Prins Maurits Laboratorium TNO (author)The various properties of an SB and a DB gun propellant were investigated before and after artificial ageing. It was found that the decrease of nitrocellulose (NC) molecular weight, due to ageing of gun propellants, leads to a decrease of the mechanical integrity of the propellant grains. The effect of grain fracture on the peak pressure was...conference paper 2003
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de Groot, J. (author), de Jongh, H.H.J. (author), TNO Voeding (author)The aim of this work was to study the effect of the formation of more heat-stable conformers of chicken egg ovalbumin during incubation at basic pH (9.9) and elevated temperature (55°C) on the protein aggregation properties at neutral pH. Native ovalbumin (N-OVA) is converted on the hours time-scale into more heat-stable forms denoted I- ...article 2003
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Krabbendam-La Haye, E.L.M. (author), de Klerk, W.P.C. (author), Miszczak, M. (author), Szymanowski, J. (author), Prins Maurits Laboratorium TNO (author)Compatibility is an important property for energetic materials and their additives such as a casing material or a binder. If these substances are incompatible an extra risk is introduced in handling and storage of ammunition and explosives. As part of a co-operation program between the Dutch TNO-PML and the Polish MIAT several compatibility...article 2003
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de Klerk, W.P.C. (author), Popescu, C. (author), van der Heijden, A.E.D.M. (author), Prins Maurits Laboratorium TNO (author)At TNO Prins Maurits Laboratory the characterisation and application of energetic materials is one of the main research topics. In this respect, the activities are focussed on using thermal analysis techniques such as TG/DTA and DSC. Standard DSC and TG/DTA techniques usually apply a linear temperature increase, During this gradual temperature...article 2003
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van de Velde, F. (author), Rollema, H.S. (author), Grinberg, N.V. (author), Burova, T.V. (author), Grinberg, V.Ya. (author), Hans Tromp, R. (author), TNO Voeding (author)A series of ι-carrageenans containing different amounts of v-carrageenan (0-23 monomer %) have been prepared from neutrally extracted carrageenan of Eucheuma denticulatum. v-Carrageenan is the biochemical precursor of ι-carrageenan. The conformational order-disorder transition and rheological properties of these carrageenans were studied using...article 2002
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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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TNO Voeding (author), Lakemond, C.M.M. (author), de Jongh, H.H.J. (author), Gruppen, H. (author), Voragen, A.G.J. (author)In heat denaturation studies conducted in the past the genetic variants of glycinin have been considered as a homogeneous group of proteins. In this work the validity of this assumption was tested. It was found by calorimetric studies that glycinin denatures heterogeneously at pH 7.6. When the temperature of isothermal treatment is increased...article 2002
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Centre for Protein Technology TNO-WU (author), Renkema, J.M.S. (author), Gruppen, H. (author), van Vliet, T. (author)The influence of pH and ionic strength on gel formation and gel properties of soy protein isolate (SPI) in relation to denaturation and protein aggregation/precipitation was studied. Denaturation proved to be a prerequisite for gel formation under all conditions of pH and ionic strength studied. Gels exhibited a low stiffness at pH >6 and a high...article 2002
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de Klerk, W.P.C. (author), van der Heijden, A.E.D.M. (author), Veltmans, W.H.M. (author), Prins Maurits Laboratorium TNO (author)In a search for new storable high performance propellants for the European Space Agency (ESA), the solid oxidiser hydrazinium nitroformate (HNF) has been identified as a very promising ingredient for a new storable composite propellant. The purity and stability of HNF after production are very important indicators for the quality of HNF. In...article 2001