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See detailCrystallization and Gelation Behavior of Low- and High Melting Waxes in Rice Bran Oil: a Case-Study on Berry Wax and Sunflower Wax
Doan, Chi Diem; Tavernier, Iris; Bin Sintang, Mohd Dona et al

in Food Biophysics (2017), 12

Low-melting berry wax (BEW) has proven to be a good oil gelator with a positive contribution to the consistency and flexibility of the structured oil. Nevertheless, the properties of BEWand the ... [more ▼]

Low-melting berry wax (BEW) has proven to be a good oil gelator with a positive contribution to the consistency and flexibility of the structured oil. Nevertheless, the properties of BEWand the corresponding oleogel have not yet been investigated in-depth. In this research, the difference in crystallization and gelling behavior between sunflower wax (SW), a high melting wax, and BEW, a low-melting wax, in rice bran oil (RBO) was investigated. The difference in melting and crystallization temperatures can be explained by the different chemical composition (long-chain wax esters in SWand shortchain fatty acids in BEW). The heterogeneity in crystal habits (unidirectional platelets versus microcrystalline particles) and polymorphism (orthorhombic versus hexagonal) are responsible for the varying gel strength and hardness of the respective SWand BEW-oleogels. The microcrystalline BEW particles aligned and reorganized during 1-month storage at 5 °C, which leaded to an increase in the gel strength and hardness of BEW-oleogel. The gelling property of SW-oleogel however did not significantly differ after 4 weeks at 5 °C, despite of the appearance of spherulitic crystalline clusters. The changes in the physical properties of wax-based oleogels during storage time were further explored using differential scanning calorimetry, polarized light microscope, powder X-ray diffraction and rheology. [less ▲]

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See detailCrystallization and morphologies of waxes in rice bran oil
Diem Doan, Chi; Patel, Ashok R.; Danthine, Sabine ULiege et al

Conference (2016, September)

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See detailCrystallization and polymorphic behavior of enzymatically produced sunflower oil based cocoa butter equivalents
Kadivar, Sheida; De Clercq, Nathalie; Danthine, Sabine ULiege et al

in European Journal of Lipid Science and Technology (2016), 118

A multi-methodological approach was used to study the isothermal crystallization of cocoa butter (CB) in the presence of sunflower oil based cocoa butter equivalents (CBEs). pNMR, DSC, oscillatory ... [more ▼]

A multi-methodological approach was used to study the isothermal crystallization of cocoa butter (CB) in the presence of sunflower oil based cocoa butter equivalents (CBEs). pNMR, DSC, oscillatory rheology, XRD, and PLM were used for this purpose. All the techniques confirmed that at 20°C isothermal crystallization of all the blends is a two-step process with formation of α crystals in the first step and formation of β’ crystals in the second step. The blends with high amount of CBEs contained more high-melting triacylglycerols (TAGs) and diacylglycerol (DAG) in compare with CB acting as seed crystals enhancing the formation of a- crystals in the first crystallization step. Therefore, the induction time of the first crystallization step was inversely related to the amount of CBE. In contrast, the subsequent polymorphic transition was delayed by the presence of the CBE due to their low-melting TAGs. However, adding up to 5% CBE did not change the Foubert’s parameters for isothermal crystallization significantly. All the blends (except 5% HOSO CBE), had a mediated β’ crystallization. Picturing of the microstructure showed that for the CB and the blends up to 50% large microstructures, indicative of the bV polymorph developed during storage. At 100%, a dense network of spherulites was formed at the beginning of the crystallization period, but upon further storage, no large morphological changes were observed. Practical applications: In recent years, the production of CB has been delayed owing to its cultivation difficulty and low yield due to pest attack, while the world cocoa prices have increased with rising demand and higher chocolate consumption. Therefore, there is a need to develop low-priced and appropriate alternatives to CB. Accordingly, in this study two sunflower oil based CBEs were produced with fatty acid mixtures in the presence of immobilized 1,3-regiospecific lipase. The results from this study could help the fats and oils industries to extend their knowledge on the crystallization and polymorphic behavior of two enzymatically produced sunflower oil based CBEs. [less ▲]

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See detailCrystallization and preliminary X-ray analysis of a bacterial psychrophilic enzyme, phosphoglycerate kinase
Mandelman, D.; Bentahir, M.; Feller, Georges ULiege et al

in Acta Crystallographica Section D-Biological Crystallography (2001), 57(Pt 11), 1666-8

The glycolytic enzyme phosphoglycerate kinase (PGK) from the Antarctic microorganism Pseudomonas sp. TACII18 is a cold-adapted enzyme that displays a high specific activity at low temperatures and ... [more ▼]

The glycolytic enzyme phosphoglycerate kinase (PGK) from the Antarctic microorganism Pseudomonas sp. TACII18 is a cold-adapted enzyme that displays a high specific activity at low temperatures and decreased thermostability relative to its mesophilic counterpart. Herein, the preliminary crystallization and structure solution of psychrophilic PGK in its native form and cocrystallized with 3-phosphoglyceric acid (3-PGA) and the ATP analogue adenylyl imidophosphate (AMP-PNP) is reported. The complexed form of PGK crystallized in 2-3 d at 290 K, whereas the native form of the enzyme required 8-12 months. Morphologically, both crystal forms are similar and X-ray diffraction experiments indicate that the crystals are isomorphous. The crystals diffracted to a resolution of 2.0 A and belong to the space group P3(2). with unit-cell parameters a = b = 58.5, c = 85.4 A. [less ▲]

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See detailCrystallization and preliminary X-ray analysis of a new L-aminopeptidase-D-amidase/D-esterase activated by a Gly-Ser peptide bond hydrolysis.
Bompard-Gilles, C; Villeret, V; Fanuel, L et al

in Acta Crystallographica Section D-Biological Crystallography (1999), 55(Pt 3), 699-701

Ochrobactrum anthropi possesses an L-aminopeptidase (DmpA) also able to act as a D-amidase/D-esterase. DmpA (40 kDa) is activated by auto-catalyzed protein splicing liberating an alpha-amino group ... [more ▼]

Ochrobactrum anthropi possesses an L-aminopeptidase (DmpA) also able to act as a D-amidase/D-esterase. DmpA (40 kDa) is activated by auto-catalyzed protein splicing liberating an alpha-amino group presumably used as a general base in the catalytic mechanism. Two crystal forms were obtained at 294 K in 13-16% PEG 2000 mono-methylether at pH 9.0, adding either 0.2 M magnesium chloride or 1 M lithium chloride. Crystals of the first form belong to the space group C2221 and diffract to 3.0 A resolution, whereas crystals of the second form belong to the space group P21212 and diffract to 2.3 A resolution. Initial screening for heavy-atom derivatives on form II crystals, has led to a well substituted Hg derivative. [less ▲]

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See detailCrystallization and preliminary X-ray analysis of a xylanase from the psychrophile Pseudoalteromonas haloplanktis
Van Petegem, F.; Collins, T.; Meuwis, Marie-Alice ULiege et al

in Acta Crystallographica Section D-Biological Crystallography (2002), 58(Part 9), 1494-1496

The 46 kDa xylanase from the Antarctic microorganism Pseudoalteromonas haloplanktis is an enzyme that efficiently catalyzes reactions at low temperatures. Here, the crystallization of both the native ... [more ▼]

The 46 kDa xylanase from the Antarctic microorganism Pseudoalteromonas haloplanktis is an enzyme that efficiently catalyzes reactions at low temperatures. Here, the crystallization of both the native protein and the SeMet-substituted enzyme and data collection from both crystals using synchrotron radiation are described. The native data showed that the crystals diffract to 1.3 Angstrom resolution and belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 50.87, b = 90.51, c = 97.23 Angstrom. SAD data collected at the peak of the selenium absorption edge proved to be sufficient to determine the heavy-atom configuration and to obtain electron density of good quality. [less ▲]

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See detailCrystallization and preliminary X-ray analysis of bacteriophage lambda lysozyme in which all tryptophans have been replaced by aza-tryptophans
Evrard, Christine ULiege; Declercq, Jean-Paul; Fastrez, Jacques

in Acta Crystallographica Section D-Biological Crystallography (1997), D53

After many unsuccessful attempts to crystallize the bacteriophage lambda lysozyme, a mutant where all the tryptophan residues have been replaced by aza-tryptophans has been crystallized by the vapor ... [more ▼]

After many unsuccessful attempts to crystallize the bacteriophage lambda lysozyme, a mutant where all the tryptophan residues have been replaced by aza-tryptophans has been crystallized by the vapor-diffusion method. The crystals are orthorhombic and belong to space group P212121 with cell dimensions a = 73.01, b = 78.80, c = 82.31 Å. Diffraction data were collected using synchrotron radiation sources. Crystals diffract to a resolution of 2.3 Å. Data from two different platinum derivatives were also recorded to 2.8 and 2.5 Å, respectively. [less ▲]

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See detailCrystallization and preliminary X-ray data for parvalbumin IIIf of Opsanus tau.
Hamoir, G.; Dideberg, O.; Charlier, Paulette ULiege

in Journal of Molecular Biology (1981), 153(2), 487-9

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See detailCrystallization and preliminary X-ray data for the exocellular beta-lactamase of Bacillus licheniformis 749/C.
Dideberg, O.; Libert, M.; Frère, Jean-Marie ULiege et al

in Journal of Molecular Biology (1985), 181(1), 145-6

The exocellular beta-lactamase from Bacillus licheniformis 749/C has been crystallized from polyethylene glycol solution at pH 5.5. An X-ray examination of the monoclinic crystals shows the space group is ... [more ▼]

The exocellular beta-lactamase from Bacillus licheniformis 749/C has been crystallized from polyethylene glycol solution at pH 5.5. An X-ray examination of the monoclinic crystals shows the space group is P21, with unit cell dimensions a = 66.77 A, b = 93.77 A, c = 43.57 A and beta = 104.5 degrees. The asymmetric unit consists of two molecules of 28,500 Mr each. The crystals are suitable for structure analysis to at least 2 A resolution. [less ▲]

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See detailCrystallization and preliminary X-ray diffraction studies of a-amylase from the antarctic psychrophile Alteromonas haloplanctis A23
Aghajari, N.; Feller, Georges ULiege; Gerday, Charles ULiege et al

in Protein Science : A Publication of the Protein Society (1996), 5(10), 2128-2129

A cold-active alpha-amylase was purified from culture supernatants of the antarctic psychrophile Alteromonas haloplanctis A23 grown at 4 degrees C. In order to contribute to the understanding of the ... [more ▼]

A cold-active alpha-amylase was purified from culture supernatants of the antarctic psychrophile Alteromonas haloplanctis A23 grown at 4 degrees C. In order to contribute to the understanding of the molecular basis of cold adaptations, crystallographic studies of this cold-adapted enzyme have been initiated because a three-dimensional structure of a mesophilic counterpart, pig pancreatic alpha-amylase, already exists. alpha-Amylase from A. haloplanctis, which shares 53% sequence identity with pig pancreatic alpha-amylase, has been crystallized and data to 1.85 A have been collected. The space group is found to be C222(1) with a = 71.40 A, b = 138.88 A, and c = 115.66 A. Until now, a three-dimensional structure of a psychrophilic enzyme is lacking. [less ▲]

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See detailCrystallization and X-ray diffraction study of the Streptomyces K15 penicillin-binding DD-transpeptidase.
Englebert, S.; Charlier, Paulette ULiege; Fonze, E. et al

in Journal of Molecular Biology (1994), 241(2), 295-7

The 262 amino acid residue long DD-transpeptidase/penicillin-binding protein of Streptomyces K15 has been crystallized at room temperature by using the hanging drop vapour diffusion technique. The ... [more ▼]

The 262 amino acid residue long DD-transpeptidase/penicillin-binding protein of Streptomyces K15 has been crystallized at room temperature by using the hanging drop vapour diffusion technique. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit cell parameters a = 46.4 A, b = 54.1 A and c = 108.3 A. They contain one protein molecule per asymmetric unit and diffract to about 1.9 A. X-ray data have been collected to 2.0 A from a native crystal. The previously published amino acid sequence of the protein has been corrected at positions 71, 72, 113, 114 and 156. [less ▲]

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See detailCrystallization behavior of neutralized and bleached shea butter under dynamic conditions
Gibon, V.; Dijckmans, P.; Blecker, Christophe ULiege et al

Poster (2016, May 01)

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See detailCrystallization behaviour of binary fat blends containing shea stearin as hard fat
Danthine, Sabine ULiege; Delatte, Sophie; Blecker, Christophe ULiege et al

in European Journal of Lipid Science and Technology [=EJLST] (2015), 117

Filling fats are used in bakery and confectionery applications. These fats are made up of complex mixtures of triacylglycerols (TAG). The crystallization, melting behaviour and polymorphic stability of ... [more ▼]

Filling fats are used in bakery and confectionery applications. These fats are made up of complex mixtures of triacylglycerols (TAG). The crystallization, melting behaviour and polymorphic stability of fat blends are determined by the behaviour of the TAGs that they contain. Filling functionalities are influenced by their fat composition but also by the processing conditions used for crystallization. In this study, the crystallization behaviour of fat blends, all based on shea stearin as hard fat (which is high in 1,3-distearoyl-2-oleoyl glycerol (SOS)) combined with either sunflower oil, shea olein or rapeseed oil, were investigated by means of pulsed nuclear magnetic resonance (pNMR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Blends containing either 30 or 40% shea stearin combined with one of the soft fats were selected as they met the criteria required for filling fats. Under static isothermal conditions (at 10°C, 15°C or 20°C), a two-step crystallization was observed for those blends, which can be explained by polymorphic transitions from a-form into more stable forms. All the selected blends exhibited different crystallization mechanisms according to theTAGcomposition of the liquid phase and their complementarity with TAG from the solid phase. [less ▲]

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See detailCrystallization behaviour of binary fat blends containing shea stearin as hard fat
Danthine, Sabine ULiege; Delatte, S; Blecker, Christophe ULiege et al

Conference (2014, September 15)

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See detailCrystallization history of enriched shergottites from Fe and Mg isotope fractionation in olivine megacrysts
Collinet, Max; Charlier, Bernard ULiege; Namur, Olivier ULiege et al

in Geochimica et Cosmochimica Acta (2017), 207

Martian meteorites are the only samples available from the surface of Mars. Among them, olivine-phyric shergottites are basalts containing large zoned olivine crystals with highly magnesian cores (Fo ... [more ▼]

Martian meteorites are the only samples available from the surface of Mars. Among them, olivine-phyric shergottites are basalts containing large zoned olivine crystals with highly magnesian cores (Fo 70–85) and rims richer in Fe (Fo 45–60). The Northwest Africa 1068 meteorite is one of the most primitive “enriched” shergottites (high initial 87Sr/86Sr and low initial ε143Nd). It contains olivine crystals as magnesian as Fo 77 and is a major source of information to constrain the composition of the parental melt, the composition and depth of the mantle source, and the cooling and crystallization history of one of the younger magmatic events on Mars (∼180 Ma). In this study, Fe-Mg isotope profiles analyzed in situ by femtosecond-laser ablation MC-ICP-MS are combined with compositional profiles of major and trace elements in olivine megacrysts. The cores of olivine megacrysts are enriched in light Fe isotopes (δ56FeIRMM-14 = −0.6 to −0.9‰) and heavy Mg isotopes (δ26MgDSM-3 = 0–0.2‰) relative to megacryst rims and to the bulk martian isotopic composition (δ56Fe = 0 ± 0.05‰, δ26Mg = −0.27 ± 0.04‰). The flat forsterite profiles of megacryst cores associated with anti-correlated fractionation of Fe-Mg isotopes indicate that these elements have been rehomogenized by diffusion at high temperature. We present a 1-D model of simultaneous diffusion and crystal growth that reproduces the observed element and isotope profiles. The simulation results suggest that the cooling rate during megacryst core crystallization was slow (43 ± 21 °C/year), and consistent with pooling in a deep crustal magma chamber. The megacryst rims then crystallized 1–2 orders of magnitude faster during magma transport toward the shallower site of final emplacement. Megacryst cores had a forsterite content 3.2 ± 1.5 mol% higher than their current composition and some were in equilibrium with the whole-rock composition of NWA 1068 (Fo 80 ± 1.5). NWA 1068 composition is thus close to a primary melt (i.e. in equilibrium with the mantle) from which other enriched shergottites derived. [less ▲]

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See detailCrystallization of a genetically engineered water-soluble primary penicillin target enzyme. The high molecular mass PBP2x of Streptococcus pneumoniae.
Charlier, Paulette ULiege; Buisson, G.; Dideberg, O. et al

in Journal of Molecular Biology (1993), 232(3), 1007-9

A genetically engineered water-soluble derivative of PBP2x of Streptococcus pneumoniae has been produced, purified and crystallized in a form suitable for X-ray diffraction analysis. The best crystals ... [more ▼]

A genetically engineered water-soluble derivative of PBP2x of Streptococcus pneumoniae has been produced, purified and crystallized in a form suitable for X-ray diffraction analysis. The best crystals have been grown at 15 degrees C, from solutions containing 8% polyethylene glycol 10,000 at pH values ranging from 3.9 to 6.0. These crystals diffract to a resolution of 3.5 A and have a space group P6(1)22 (or enantiomorph) with unit cell dimensions of a = b = 162.2 A, c = 171.8 A, alpha = beta = 90 degrees, gamma = 120 degrees. The molecular mass and cell dimensions suggest that there is one molecule of enzyme per asymmetric unit. The breakdown of a chromogenic cephalosporin derivative diffused into a crystal reveals clearly that the enzyme is active in the crystalline state. [less ▲]

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See detailCrystallization of ornithine acetyltransferase from yeast by counter-diffusion and preliminary X-ray study
Maes, D.; Crabeel, M.; Van de Weerdt, Cécile ULiege et al

in Acta Crystallographica Section F-Structural Biology and Crystallization Communications (2006), 62(Part 12), 1294-1297

A study is presented on the crystallization of ornithine acetyltransferase from yeast, which catalyzes the fifth step in microbial arginine synthesis. The use of the counter-diffusion technique removes ... [more ▼]

A study is presented on the crystallization of ornithine acetyltransferase from yeast, which catalyzes the fifth step in microbial arginine synthesis. The use of the counter-diffusion technique removes the disorder present in one dimension in crystals grown by either the batch or hanging-drop techniques. This makes the difference between useless crystals and crystals that allow successful determination of the structure of the protein. The crystals belong to space group P4, with unit-cell parameters a = b = 66.98, c = 427.09 angstrom, and a data set was collected to 2.76 angstrom. [less ▲]

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See detailCrystallization of vitreous high-T-c superconducting oxide through laser zone melting method.
Ausloos, Marcel ULiege; Bougrine, Hassan ULiege; Cloots, Rudi ULiege et al

in Institute of Physics Conference Series (1995), 148

We synthesized Bi2Sr2CaCu2O8-y ceramics through the vitreous route. After insertion in epoxy resin, we exposed the materials to a CO2 laser beam. Various intensities and sweeping conditions were examined ... [more ▼]

We synthesized Bi2Sr2CaCu2O8-y ceramics through the vitreous route. After insertion in epoxy resin, we exposed the materials to a CO2 laser beam. Various intensities and sweeping conditions were examined. We observed the samples in high resolution polarized light microscopy and with electron scanning microscopy. Crystallization zones could be detected. A systematic analysis gave the correlation between the behavior of the material and its synthesis conditions. Electrical properties were measured through micro-electrode deposited on the surface at various locations. No superconductivity was found. The optimization of such a process and potential applications will be discussed. [less ▲]

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See detailCrystallization sequence and magma chamber processes in the ferrobasaltic Sept Iles layered intrusion, Canada
Namur, Olivier ULiege; Charlier, Bernard ULiege; Toplis, Michael et al

in Journal of Petrology (2010), 51

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See detailCrystallization, X-ray characterization and selenomethionine phasing of Mlc1p bound to IQ motifs from myosin V
Terrak, Mohammed ULiege; Otterbein, L. R.; Wu, G. et al

in Acta Crystallographica Section D-Biological Crystallography (2002), 58(Pt 10 Pt 2), 1882-5

Mlc1p is a calmodulin-like protein from the budding yeast Saccharomyces cerevisiae, where it has been identified as a subunit of a class V myosin, Myo2p, and a binding partner of an IQGAP-like protein ... [more ▼]

Mlc1p is a calmodulin-like protein from the budding yeast Saccharomyces cerevisiae, where it has been identified as a subunit of a class V myosin, Myo2p, and a binding partner of an IQGAP-like protein, Iqg1p. Through its interactions with these two proteins, Mlc1p plays a role in polarized growth and cytokinesis. Mlc1p has been crystallized in complexes with four different IQ target motifs from the neck region of Myo2p: IQ2, IQ3, IQ4 and IQ2-IQ3 (referred to as IQ2,3). Electron-density maps for two of the complexes (Mlc1p-IQ4 and Mlc1p-IQ2,3) were obtained from multiple anomalous dispersion (MAD) experiments based on selenomethionine derivatives. The other two structures (Mlc1p-IQ2 and Mlc1p-IQ3) were determined by molecular replacement using the partially refined structure of Mlc1p-IQ2,3 as a search model. [less ▲]

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