References of "De Pauw, Edwin"
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See detailGrasshoppers as a food source? A review
Paul, Aman ULg; Frederich, Michel ULg; Uyttenbroeck, Roel ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (in press), 20(AgricultureIsLife),

Description of the subject. Current trends suggest an increasing future demand for conventional meats, which indicates a strong need to shift this dependency to other alternative protein sources such as ... [more ▼]

Description of the subject. Current trends suggest an increasing future demand for conventional meats, which indicates a strong need to shift this dependency to other alternative protein sources such as insects. Literature. From a nutritional point of view, of all the insects consumed globally, grasshoppers are particularly important as a human food. Data from the literature regarding the nutrient composition, amino acid profile, fatty acid profile, mineral composition and vitamin content of grasshoppers as reviewed in this paper, suggest that a number of grasshopper species are a good source of nutrients. It also highlights some of the health related aspects that might arise from the consumption of grasshoppers, mostly linked to agricultural practices and the allergic response of sensitive individuals. The paper also summarizes some religious, social and economic factors that are associated with grasshopper consumption. Conclusions. The success of introducing grasshoppers as a novel food in western countries depends on changes in consumer attitudes. It would be interesting to develop food products derived from grasshoppers in a form acceptable to consumers. Furthermore, it is important to explore the food potential of some grasshopper species native to western countries and to develop their rearing methodologies to enhance availability. [less ▲]

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See detailMass-spectrometry-based method for screening of new peptide ligands for G-protein-coupled receptors
Cologna Takeno, Camila; Gilles, Nicolas; Echterbille, Julien ULg et al

in Analytical and Bioanalytical Chemistry (in press)

G-protein-coupled receptors (GPCRs) constitute the largest family of transmembrane proteins. Although implicated in almost all physiological processes in the human body, most of them remain unexploited ... [more ▼]

G-protein-coupled receptors (GPCRs) constitute the largest family of transmembrane proteins. Although implicated in almost all physiological processes in the human body, most of them remain unexploited, mostly because of the lack of specific ligands. The objective of this work is to develop a new mass-spectrometry-based technique capable of identifying new peptide ligands for GPCRs. The strategy is based on the incubation of cellular membranes overexpressing GPCRs with a mixture of peptides that contains potential ligands. Peptide ligands bind to the receptors, whereas other peptides remain in the binding buffer. Bound peptides are eluted from membranes and directly detected, identified, and characterized by MALDI TOF–TOF. The results reveal the efficacy of the procedure for selecting a specific ligand of GPCRs in both simple and complex mixtures of peptides. This new approach may offer direct purification, identification, and characterization of the new ligand in a single workflow. The proposed method is labeling-free and, unlike radio-binding and other techniques, it does not require a previously known labeled ligand of the studied GPCR. All these properties greatly reduce the experimental constraints. Moreover, because it is not based on the principle of a competitive specific binding, this technique constitutes a new tool to discover new ligands not only for known GPCRs, but also for orphan GPCRs [less ▲]

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See detailPeptidoglycan fragments separation by CE/LC-MS
Boulanger, Madeleine ULg; Delvaux, Cédric ULg; Far, Johann ULg et al

Poster (2016, May 24)

In Bacillus licheniformis 749/I, the induction of BlaP beta-lactamase relies on a complex regulation system. During this process, the intracellular repressor BlaI is inactivated by a dipeptide coming from ... [more ▼]

In Bacillus licheniformis 749/I, the induction of BlaP beta-lactamase relies on a complex regulation system. During this process, the intracellular repressor BlaI is inactivated by a dipeptide coming from the peptidoglycan (PG) degradation via an “AND Gate” regulation. This regulation involves the cellular stress induced by the beta-lactam, the membrane receptor BlaR1 and the PG turnover. Briefly, the induction occurs when the extracellular domain of BlaR1 is acylated by the antibiotic which leads to a reorganization of the transmembrane segments and the receptor autocleavage. Simultaneously, the beta-lactam partially inhibits the penicillin-binding protein 1 (PBP1), triggering increased PG turnover and accumulation of PG fragments. Some of these fragments could enter in the cytoplasm and undergo enzymatic degradations which lead to the formation of the pro co-activator (tripeptide L-Ala-D-Glu-m-A2pm). This pro co-activator generates the co-activator, the dipeptide D-Glu-m-A2pm. Nowadays the nature and the concentration of PG fragments inside the cytoplasm are unknown. Therefore, the development of different analytical methods is required in order to identify those cytoplasmic fragments. In this poster, three different ways to separate PG fragments are discussed. [less ▲]

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See detailFrom Valeriana officinalis to cancer therapy: the success of a bio-sourced compound
Hamaïdia, Malik ULg; Barez, Pierre-Yves ULg; Carpentier, Alexandre ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2016), 20

Over the centuries, bio-sourced compounds isolated from plants, insects and microorganisms have been a potent source of drugs for the treatment of human diseases. In this review, we recapitulate the story ... [more ▼]

Over the centuries, bio-sourced compounds isolated from plants, insects and microorganisms have been a potent source of drugs for the treatment of human diseases. In this review, we recapitulate the story of one of these compounds, 2-propylpentanoic acid, derived from the Valeriana officinalis flowering plant and its path to validation as a cancer treatment. [less ▲]

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See detailContribution of Capillary Electrophoresis and Ion Mobility Spectrometry to probe conformational change during desolvation
Far, Johann ULg; Delvaux, Cédric ULg; Kune, Christopher ULg et al

Conference (2016, January 28)

The transfer of ions from the solution to the gas phase is a critical step to produce « native species ». Coming from a highly solvating medium, ionic species will tend to find a new equilibrium ... [more ▼]

The transfer of ions from the solution to the gas phase is a critical step to produce « native species ». Coming from a highly solvating medium, ionic species will tend to find a new equilibrium conformation in the gas phase. The pathway to reach the thermodynamically stable conformation involves crossing potential barriers of different heights. When these barriers are too high compared to the internal energy of the ions, it will result in “partial memories” (as structural preservation) of the conformation in solution. In order to evaluate the effect of the solvent evaporation and of the various collision processes encountered by the ions in the mass spectrometer, we developed two strategies: The first strategy consists in comparing in a single experiment the shape of the ions in solution and in the gas phase. Data are obtained by coupling Capillary Electrophoresis (CE) with Ion Mobility Mass Spectrometry (IMS). Drift times in solution and in the gas phase are directly compared. Deviations from their correlation points out changes in folding upon desolvatation. Preliminary results show that some of peptides issued from tryptic digest of BSA clearly change their conformation during desolvatation. The second strategy consists to monitor the shape of the different conformers observed for the intact cytochrome C during native runs in capillary electrophoresis and “native” ion mobility mass spectrometry, both using a physiological TRIS acetic pH7 buffer compared to a “MS friendly” ammonium acetate pH7 buffer. Finally as preliminary study, we proposed to use homopolymers for better understanding about the folding behavior in gas phase and the resulting shape of these ions using ion mobility spectrometry. [less ▲]

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See detailDe novo sequencing using MELD proteolysis coupled to a "sequence assembly" algorithm
Mazzucchelli, Gabriel ULg; Zimmerman, Tyler A; Smargiasso, Nicolas ULg et al

Poster (2016, January 22)

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See detailStructural analysis of ruthenium–arene complexes using ion mobility mass spectrometry, collision-induced dissociation, and DFT
Cserwinska, Izabella; Far, Johann ULg; Kune, Christopher ULg et al

in Dalton Transactions (2016), 45

Ion mobility mass spectrometry (IM-MS) and collision-induced dissociation (CID) techniques were used to investigate the influence of the phosphine ligand on the physicochemical properties of [RuCl2(p ... [more ▼]

Ion mobility mass spectrometry (IM-MS) and collision-induced dissociation (CID) techniques were used to investigate the influence of the phosphine ligand on the physicochemical properties of [RuCl2(p-cymene)(PCy3)] (1), [RuCl2(p-cymene)-(PPh3)] (2), and [RuCl2(p-cymene)(PTA)] (3) in the gas phase (PTA is 1,3,5-triaza-7-phosphaadamantane). Electrospray ionization of complexes 1 and 2 led to the corresponding [RuCl(p-cymene)(PR3)]+ ions via the dissociation of a chlorido ligand, whereas RAPTA-C (3) afforded two molecular ions by in-source oxidation ([RuIIICl2(p-cymene)(PTA)]+) or protonation ([RuCl2(p-cymene)(PTA+H)]+). Control experiments showed that the balance between these two ionization paths was strongly influenced by the nature of the solvent used for infusion. Collision cross sections (CCSs) of the four molecular ions accurately reflected the variations of steric bulk inferred from the Tolman steric parameters (θ) of the phosphine ligands. Moreover, DFT calculations combined with a model based on the kinetic theory of gases (the trajectory method of the IMoS software) afforded reliable CCS predictions. The almost two times higher dipole moment of [RuCl2(p-cymene)-(PTA+H)]+ (μ = 13.75 D) compared to [RuIIICl2(p-cymene)(PTA)]+ (μ = 7.18 D) was held responsible for increased ion-induced dipole interactions with a polarizable drift gas such as N2. Further experiments with He and CO2 confirmed that increasing the polarizability of the buffer gas improved the separation between the two molecular ions derived from complex 3. The fragmentation patterns of complexes 1–3 were determined by CID. The sequence of collision voltages at which 50% of a precursor ion dissociates (V50) recorded for the molecular ions derived from compounds 1–3 was in good agreement with simple electronic considerations based on the donor strength of the phosphine ligand. Thus, the CCS and V50 parameters used to determine the shape and stability of ionic species in the gas phase are complementary to the Tolman steric and electronic parameters (θ and TEP) commonly used by organometallic chemists in condensed phases. [less ▲]

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See detailEffet inflammatoire des extraits de Cupressus sempervirens planté dans l’Est de l’Algérie : du modèle murin à la stimulation des cellules BEAS-2B par l’allergène majeur Cup s 1
Bouguenoun, Imene; De Pauw-Gillet, Marie-Claire ULg; Bensakhri, Z et al

in Revue Française d'Allergologie (2016), 56

Cupressus sempervirens est l’une des espèces les plus répandues en Algérie ayant une capacité allergénique très élevée. Nous avons étudié,d’abord, comment l’instillation nasale des différentes fractions ... [more ▼]

Cupressus sempervirens est l’une des espèces les plus répandues en Algérie ayant une capacité allergénique très élevée. Nous avons étudié,d’abord, comment l’instillation nasale des différentes fractions de l’extrait pollinique de cette espèce peut moduler la réponse immunitaire chez les souris, et, ensuite, la stimulation des cellules épithéliales bronchiques humaines (BEAS-2B) par l’allergène majeur, identifié par spectrométrie de masse et purifié par chromatographie échangeuse d’ions. La sensibilisation des souris a révélé, d’une part, une diminution du nombre de neutrophiles et une augmentation des éosinophiles, et, d’autre part, une augmentation significative du total cellulaire dans le liquide du lavage bronchoalvéolaire.L’étude histologique des poumons a montré une présence d’infiltrat inflammatoire et d’oedème péri-bronchique. La spectrométrie de masse nous a permis de mettre en évidence la présence de l’allergène majeur Cup s 1 dans toutes les fractions avec une présence spécifique du Cup s 3 et Cupa 1 dans la fraction 4. Cet allergène avait le potentiel pour stimuler la libération de l’IL-8 et l’IL-6 par la ligné cellulaire, BEAS-2B, in vitro d’une manière dose-dépendante [less ▲]

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See detailAn Improved Molecular Histology Method for Ion Suppression Monitoring and Quantification of Phosphatidyl Cholines During MALDI MSI Lipidomics Analyses.
Jadoul, Laure ULg; Smargiasso, Nicolas ULg; Pamelard, Fabien et al

in OMICS : A Journal of Integrative Biology (2016), 20(2), 110-21

Tissue lipidomics is one of the latest omics approaches for biomarker discovery in pharmacology, pathology, and the life sciences at large. In this context, matrix-assisted laser desorption/ionization ... [more ▼]

Tissue lipidomics is one of the latest omics approaches for biomarker discovery in pharmacology, pathology, and the life sciences at large. In this context, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is the most versatile tool to map compounds within tissue sections. However, ion suppression events occurring during MALDI MSI analyses make it impossible to use this method for quantitative investigations without additional validation steps. This is especially true for lipidomics, since different lipid classes are responsible for important ion suppression events. We propose here an improved lipidomics method to assess local ion suppression of phospatidylcholines in tissues. Serial tissue sections were spiked with different amounts of PC(16:0 d31/18:1) using a nebulization device. Settings for standard nebulization were strictly controlled for a detection similar to when using spiked tissue homogenates. The sections were simultaneously analyzed by MALDI MSI using a Fourier transform ion cyclotron resonance analyzer. Such a spray-based approach allows taking into account the biochemical heterogeneity of the tissue for the detection of PC(16:0 d31/18:1). Thus, here we present the perspective to use this method for quantification purposes. The linear regression lines are considered as calibration curves and we calculate PC(16:0/18:1) quantification values for different ROIs. Although those values need to be validated by a using a different independent approach, the workflow offers an insight into new quantitative mass spectrometry imaging (q-MSI) methods. This approach of ion suppression monitoring of phosphocholines in tissues may be highly interesting for a large range of applications in MALDI MSI, particularly for pathology using translational science workflows. [less ▲]

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See detailComparison of serum fractionation methods by data independent label-free proteomics
Baiwir, Dominique ULg; Mazzucchelli, Gabriel ULg; Smargiasso, Nicolas ULg et al

in EuPA Open Proteomics (2015), 9

Off-line sample prefractionations applied prior to biomarker discovery proteomics are options to enable more protein identifications and detect low-abundance proteins. This work compared five commercial ... [more ▼]

Off-line sample prefractionations applied prior to biomarker discovery proteomics are options to enable more protein identifications and detect low-abundance proteins. This work compared five commercial methods efficiency to raw serum analysis using label-free proteomics. The variability of the protein quantities determined for each process was similar to the unprefractionated serum. A 49% increase in protein identifications and 12.2% of reliable quantification were obtained. A 61 times lower limit of protein quantitation was reached compared to protein concentrations observed in raw serum. The concentrations of detected proteins were confronted to estimated reference values. [less ▲]

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See detailGender differences in responses in Gammarus pulex exposed to BDE-47: a gel-free proteomic approach
Gismondi, Eric ULg; Mazzucchelli, Gabriel ULg; De Pauw, Edwin ULg et al

in Ecotoxicology & Environmental Safety (2015), 122

Very few ecotoxicological studies have considered differences in toxic effects on male and female organisms. Here, we investigated protein expression differences in caeca of Gammarus pulex males and ... [more ▼]

Very few ecotoxicological studies have considered differences in toxic effects on male and female organisms. Here, we investigated protein expression differences in caeca of Gammarus pulex males and females under control conditions (unexposed) and after 96 h exposure to BDE-47. Using gel-free proteomic analysis, we have identified 45 proteins, of which 25 were significantly differently expressed according to sex and/or BDE-47 exposure. These proteins were involved in several biological processes such as energy metabolism, chaperone proteins, or transcription/translation. In unexposed amphipods, 11 proteins were significantly over-expressed in females, and 6 proteins were over-expressed in males. Under BDE-47 stress, 7 proteins were differently impacted according to sex. For example, catalase was over-expressed in exposed females and under-expressed in exposed males, as compared to respective controls. Conversely, proteins involved in energy metabolism were up-regulated in males and down-regulated in females. Our proteomic study showed differences in responses of males and females to BDE-47 exposure, emphasizing that sex is a confounding factor in ecotoxicological assessment. However, due to the limited information existing in databases on Gammarids, it was difficult to define a BDE-47 mechanism of action. The gel-free proteomic seems to be a promising method to develop in future ecotoxicological studies and thus, to improve our understanding of the mechanism of action of xenobiotics. [less ▲]

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See detailImpact of Regiella insecticola infection on EBF production in Acyrthosiphon pisum Harris
Bauwens, Julien ULg; Mazzucchelli, Gabriel ULg; De Pauw, Edwin ULg et al

Conference (2015, November 06)

Symbionts of aphids influence their host from many points of view. We investigate the potential influence of bacterial symbionts on the production and emission of the aphid alarm pheromone, E-β-franesene ... [more ▼]

Symbionts of aphids influence their host from many points of view. We investigate the potential influence of bacterial symbionts on the production and emission of the aphid alarm pheromone, E-β-franesene. Some trends could be observed in the total EβF production. Particularly, aphid strains infected by Buchnera only seemed to produce less alarm pheromone. By contrast, the presence of Regiella insecticola seemed to increase EβF production. Mevalonate pathway was investigated by RT-qPCR. This analysis showed a slightly lower transcription level o mIPPS in Regiella-infected strains. This enzyme is involved in the last step of EβF production. By contrast, two enzymes involved respectively in the linkage and release of farnesyl moeities on proteins c-terminal ends. Escape tests were conducted to assay if these results were traduced by differential behavior in front of a predator. Preliminary results showed significantly higher dropping behavior for Regiella-infected strains. [less ▲]

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