References of "De Pauw, Edwin"
     in
Bookmark and Share    
Full Text
See detailPeptidoglycan fragments separation by CE/LC-MS
Boulanger, Madeleine ULiege; Delvaux, Cédric ULiege; Far, Johann ULiege 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 ▲]

Detailed reference viewed: 89 (9 ULiège)
Full Text
Peer Reviewed
See detailNew methodology to detect toxin-nAChRs binding by MALDI-TOF mass spectrometry
Echterbille, Julien ULiege; Gilles, Nicolas; Araoz, Romulo et al

Conference (2016, April 18)

More than 50 thousands of venomous species are currently indexed in the world. Each of their venoms is composed of 200 to 1000 different toxins which potentially exhibit a high selectivity for membrane ... [more ▼]

More than 50 thousands of venomous species are currently indexed in the world. Each of their venoms is composed of 200 to 1000 different toxins which potentially exhibit a high selectivity for membrane receptors such as G-protein coupled receptors or ion channels such nicotinic acetylcholine receptors (nAChRs). The latter have been a target for drug discovery efforts, primarily for central nervous system indications. Therefore, it appears of prime interest to design new pharmacological tools and potentially discover future drugs targeting this kind of ion channels. In 2015, our group published a new mass spectrometry-based methodology to screen peptide ligands for G protein coupled receptors1. The proof of concept of this methodology was built by studying the binding of [Arg8]-vasopressin (AVP) on type 2-vasopressin receptor (V2). We extended this methodology to another system ligand-receptor. As all Conus species venoms investigated so far contain at least one toxin antagonizing nAChRs: the alpha-conotoxins. Therefore, the ligand-receptor model couple that has been chosen is nAChRs-alpha-conotoxins. Experimentally, fragments of cellular membranes over-expressing nAChRs were incubated with Bovine Serum Albumine (BSA) tryptic digest (~100 peptide toxins) doped by a small amount of Alpha-conotoxins. After 2 hours incubation, free and bound fractions were purified with a combination of centrifugation and micro column purifications. Samples were finally analyzed with a MALDI-TOF/TOF mass spectrometer. By comparison of the intensity of Alpha-conotoxins in the free and in the bound fractions, we clearly detect an enrichment of nAChRs ligand in the latter. In order to transpose the methodology to natural mixture, we applied the workflow to crude conus venoms. We incubated membranes over-expressing nAChRs with Conus textile venom which is known to possess at least 5 different alpha-conotoxins. Thanks to our approach, we were able to detect an enrichment of these known ligands in the bound fraction. In order to validate the potential of our approach, the next step of this work will be the incubation of a Conus venom for which no alpha-conotoxins have been described. [less ▲]

Detailed reference viewed: 82 (3 ULiège)
Full Text
Peer Reviewed
See detailFrom Valeriana officinalis to cancer therapy: the success of a bio-sourced compound
Hamaïdia, Malik ULiege; Barez, Pierre-Yves ULiege; Carpentier, Alexandre ULiege et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (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 ▲]

Detailed reference viewed: 174 (43 ULiège)
Full Text
See detailContribution of Capillary Electrophoresis and Ion Mobility Spectrometry to probe conformational change during desolvation
Far, Johann ULiege; Delvaux, Cédric ULiege; Kune, Christopher ULiege 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 ▲]

Detailed reference viewed: 49 (10 ULiège)
Full Text
Peer Reviewed
See detailDe novo sequencing using MELD proteolysis coupled to a "sequence assembly" algorithm
Mazzucchelli, Gabriel ULiege; Zimmerman, Tyler A; Smargiasso, Nicolas ULiege et al

Poster (2016, January 22)

Detailed reference viewed: 39 (3 ULiège)
Full Text
See detailBiomarker for osteoarthritis and use thereof
Henrotin, Yves ULiege; Gharbi, Myriam; DEBERG, Michelle ULiege et al

Patent (2016)

Detailed reference viewed: 15 (1 ULiège)
Full Text
Peer Reviewed
See detailEXPEL: A Novel Non-Destructive Method for Mining Soluble Tumor Biomarkers
Costanza, B; Blomme, A; Bellahcene, Akeila ULiege et al

in Acta Gastro-Enterologica Belgica (2016), 79(1), 11

Detailed reference viewed: 38 (9 ULiège)
Full Text
Peer Reviewed
See detailMeasurement of emerging dechloranes in human serum using modulated gas chromatography coupled to electron capture negative ionization time-of-flight mass spectrometry
Brasseur, C; Pirard, C; L'Homme, B et al

in Rapid Communications in Mass Spectrometry (2016), 30

Detailed reference viewed: 19 (0 ULiège)
Full Text
Peer Reviewed
See detailProtein N-glycosylation and N-glycan trimming are required for postembryonic development of the pest beetle Tribolium castaneum
Walski, Tomasz; Van Damme, Els; Smargiasso, Nicolas ULiege et al

in Scientific Reports (2016)

In holometabolous insects the transition from larva to adult requires a complete body reorganization and relies on N-glycosylated proteins. N-glycosylation is an important posttranslational modification ... [more ▼]

In holometabolous insects the transition from larva to adult requires a complete body reorganization and relies on N-glycosylated proteins. N-glycosylation is an important posttranslational modification that influences protein activity but its impact on the metamorphosis has not been studied yet. Here we used the red flour beetle, Tribolium castaneum, to perform a first comprehensive study on the involvement of the protein N-glycosylation pathway in metamorphosis. The transcript levels for genes encoding N-glycan processing enzymes increased during later developmental stages and, in turn, transition from larva to adult coincided with an enrichment of more extensively modified paucimannose glycans, including fucosylated ones. Blockage of N-glycan attachment resulted in larval mortality, while RNAi of α-glucosidases involved in early N-glycan trimming and quality control disrupted the larva to pupa transition. Additionally, simultaneous knockdown of multiple genes responsible for N-glycan processing towards paucimannose structures revealed their novel roles in pupal appendage formation and adult eclosion. Our findings revealed that, next to hormonal control, insect post-embryonic development and metamorphosis depend on protein N-glycan attachment and efficient N-glycan processing. Consequently, disruption of these processes could be an effective new approach for insect control. [less ▲]

Detailed reference viewed: 26 (0 ULiège)
Full Text
Peer Reviewed
See detailIon Mobility-Mass Spectrometry as a Tool for the Structural Characterization of Peptides Bearing Intramolecular Disulfide Bond(s)
Massonnet, Philippe ULiege; Haler, Jean ULiege; Upert, Gregory et al

in Journal of the American Society for Mass Spectrometry (2016)

Detailed reference viewed: 55 (25 ULiège)
Full Text
Peer Reviewed
See detailSphingolipids: promising lipid-class molecules with potential applications for industry. A review
Miazek, Krystian ULiege; Lebecque, Simon ULiege; Hamaïdia, Malik ULiege et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016), (20(S1)), 321-336

Detailed reference viewed: 31 (8 ULiège)
Full Text
Peer Reviewed
See detailIn Situ Analysis of Bacterial Lipopeptide Antibiotics by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging
Debois, Delphine ULiege; Ongena, Marc ULiege; Cawoy, H. et al

in Nonribosomal Peptide and Polyketide Biosynthesis : Methods and Protocols (2016)

Detailed reference viewed: 39 (10 ULiège)