References of "De Pauw, Edwin"
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See detailIdentification of proteins from wild cardoon flowers (Cynara cardunculus L.) by a proteomic approach
Ben Amira, Amal; Bauwens, Julien ULg; De Pauw, Edwin ULg et al

in Journal of Chemical Biology (in press)

Proteomic approach was applied to identify total proteins, particularly the enzymatic content, from wild cardoon flowers. As the selection of an appropriate sample preparation method is the key for ... [more ▼]

Proteomic approach was applied to identify total proteins, particularly the enzymatic content, from wild cardoon flowers. As the selection of an appropriate sample preparation method is the key for getting reliable results, two different extraction/precipitation methods (trichloroacetic acid and phenol/ammonium acetate) were tested on fresh and lyophilized flowers. After two-dimensional electrophoresis (2D–E) separations, a better protein pattern was obtained after phenol extraction from lyophilized flowers. Only 46 % of the total analyzed spots resulted in a protein identification by mass spectrometry MALDI-TOF. Four proteases (cardosins A, E, G, and H), which have become a subject of great interest in dairy technology, were identified. They presented molecular weights and isoelectric points very close and high levels of homology between matched peptides sequences. The absence of the other cardosins (B, C, D, and F) could be an advantage, as it reduces the excessive proteolytic activity that causes bitter flavors and texture defects, during cheese making. [less ▲]

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See detailDiscovery and characterization of EIIB, a new α-conotoxin from Conus ermineus venom by nAChRs affinity capture monitored by MALDI-TOF/TOF mass spectrometry
Echterbille, Julien; Gilles, Nicolas; Araoz, Romulo et al

in Toxicon (2017), 130

Animal toxins are peptides that often bind with remarkable affinity and selectivity to membrane receptors such as nicotinic acetylcholine receptors (nAChRs). The latter are, for example, targeted by α ... [more ▼]

Animal toxins are peptides that often bind with remarkable affinity and selectivity to membrane receptors such as nicotinic acetylcholine receptors (nAChRs). The latter are, for example, targeted by α-conotoxins, a family of peptide toxins produced by venomous cone snails. nAChRs are implicated in numerous physiological processes explaining why the design of new pharmacological tools and the discovery of potential innovative drugs targeting these receptor channels appear so important. This work describes a methodology developed to discover new ligands of nAChRs from complex mixtures of peptides. The methodology was set up by the incubation of Torpedo marmorata electrocyte membranes rich in nAChRs with BSA tryptic digests (>100 peptides) doped by small amounts of known nAChRs ligands (α-conotoxins). Peptides that bind to the receptors were purified and analyzed by MALDI-TOF/TOF mass spectrometry which revealed an enrichment of α-conotoxins in membrane-containing fractions. This result exhibits the binding of α-conotoxins to nAChRs. Negative controls were performed to demonstrate the specificity of the binding. The usefulness and the power of the methodology were also investigated for a discovery issue. The workflow was then applied to the screening of Conus ermineus crude venom, aiming at characterizing new nAChRs ligands from this venom, which has not been extensively investigated to date. The methodology validated our experiments by allowing us to bind two α-conotoxins (α-EI and α-EIIA) which have already been described as nAChRs ligands. Moreover, a new conotoxin, never described to date, was also captured, identified and sequenced from this venom. Classical pharmacology tests by radioligand binding using a synthetic homologue of the toxin confirm the activity of the new peptide, called α-EIIB. The Ki value of this peptide for Torpedo nicotinic receptors was measured at 2.2 ± 0.7 nM. [less ▲]

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See detailDiversity in sequences, post-translational modifications and expected pharmacological activities of toxins from four Conus species revealed by the combination of cutting-edge proteomics, transcriptomics and bioinformatics
Degueldre, Michel; Verdenaud, Marion; Garikoitz, Legarda et al

in Toxicon (2017), 130

Venomous animals have developed a huge arsenal of reticulated peptides for defense and predation. Based on various scaffolds, they represent a colossal pharmacological diversity, making them top ... [more ▼]

Venomous animals have developed a huge arsenal of reticulated peptides for defense and predation. Based on various scaffolds, they represent a colossal pharmacological diversity, making them top candidates for the development of innovative drugs. Instead of relying on the classical, low-throughput bioassay-guided approach to identify innovative bioactive peptides, this work exploits a recent paradigm to access to venom diversity. This strategy bypasses the classical approach by combining high-throughput transcriptomics, proteomics and bioinformatics cutting-edge technologies to generate reliable peptide sequences. The strategy employed to generate hundreds of reliable sequences from Conus venoms is deeply described. The study led to the discovery of (i) conotoxins that belong to known pharmacological families targeting various GPCRs or ion-gated channels, and (ii) new families of conotoxins, never described to date. It also focusses on the diversity of genes, sequences, folds, and PTM's provided by such species. [less ▲]

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See detailProteomic differential distribution of 53BP1 in serrated and conventional adenomas validated by histological characterisation
QUESADA-CALVO, Florence ULg; Merli, Angela-Maria ULg; MASSOT, Charlotte ULg et al

Poster (2017, February 10)

INTRODUCTION: Sessile serrated adenoma/polyp (SSA/p) is a precancerous lesion, mostly located in the right side of the colon (cecum, ascending and transverse colon). The difficulty is to visualize this ... [more ▼]

INTRODUCTION: Sessile serrated adenoma/polyp (SSA/p) is a precancerous lesion, mostly located in the right side of the colon (cecum, ascending and transverse colon). The difficulty is to visualize this lesion during colonoscopy because of its subtle appearance. MATERIAL AND METHOD: We compared proteomes of serrated polyps (SSA/p) and conventional adenomas using residual human formalin fixed paraffin embedded (FFPE) samples. FFPE-FASP method was applied on samples before label free proteomic analysis. Immunohistochemistry (IHC) characterisation of one candidate marker was performed for tissue validation on an independent set of samples including: conventional adenomas (low and high-grade dysplasia), serrated polyps (hyperplastic polyps, SSA/p and traditional serrated adenoma) and finally normal colon (taken at the margin of colorectal cancer (CRC) or of diverticular disease). RESULTS: Proteomics provided 765 proteins (out of 5992 proteins identified) significantly discriminating conventional adenomas from serrated lesions. We selected 53BP1 (Tumor suppressor p53-binding protein 1) among these for IHC validation, because of its tumor suppressor gene function and role as a mediator of DNA damage checkpoint. 53BP1 appeared significantly up-regulated in proteomes of low and high grade adenomas compared to these of normal tissue and SSA/p. 53BP1 IHC signal was located in the nucleus and the percentage of positive nucleus decreased in serrated polyps, especially in crypts and in the border epithelium, confirming part of the proteomic results. CONCLUSION: This study highlights potential marker proteins, including 53BP1 from which IHC signal was strongly decreased in some serrated polyps. The loss of 53BP1 has been associated with tumour progression and poor prognosis, while little is currently known about its involvement in precancerous CRC lesions. 53BP1 decrease of expression in the nucleus and therefore possible loss of function in some epithelial cells could reflect important changes occurring during dysplasia to neoplasia progression in serrated lesions. [less ▲]

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See detailIdentification of proteins discriminating inflammation induced dysplasia from simple inflammation in ulcerative colitis by laser capture microdissection and label free proteomics – a pilot study
Merli, Angela-Maria ULg; QUESADA-CALVO, Florence ULg; MASSOT, Charlotte ULg et al

Conference (2017, February 09)

Chronic colonic inflammation in ulcerative colitis (UC) may induce dysplasia, which can itself progress and transform into neoplasia. Diagnosis of dysplasia in UC remains difficult particularly when ... [more ▼]

Chronic colonic inflammation in ulcerative colitis (UC) may induce dysplasia, which can itself progress and transform into neoplasia. Diagnosis of dysplasia in UC remains difficult particularly when tissue inflammation is present. The aim of this retrospective pilot study was to highlight proteins specifically associated with inflammation induced dysplasia in UC. We performed a pilot experiment on 15 Formalin-Fixed, Paraffin-Embedded (FFPE) samples isolated from 5 cases of UC patients with a Polypoïd Pedunculated dysplasia (UC-PP). We compared the proteomes of the UC-PP, the inflammatory (UC-I) and the normal (UC-NL) tissues of each patient. We performed Laser Capture Microdissection (LCM) in order to collect only epithelial cells, avoiding inflammatory infiltrating ones. Label free proteomic analysis using a 2D-nanoUPLC coupled with a hybrid Quadrupole-Orbitrap was applied, as well as differential analysis on the paired samples. Immunohistochemistry (IHC) characterisation of one of the selected proteins of interest was used for validation. Out of 985 quantified proteins, 7 were found significantly more abundant in UC-PP compared to UC-I tissues, with 6 being only detected in UC-PP using proteomics. One of these is Solute Carrier Family 12 member 2 (SLC12A2), also known as Na-K-2Cl co-transporter 1 (NKCC1), a protein involved in ionic balance, in T-cell migration promotion and in some features involved in cancer development like proliferation, migration or invasion. IHC results obtained were in correlation with proteomic results and showed that SLC12A2 was more abundant in UC-PP tissue than in UC-I and UC-NL tissues, with a signal clearly delimiting the dysplastic region from the surrounding inflammatory tissue. This pilot experiment shows a different proteomic profile in inflammation-associated dysplasia and simple inflammation. This should be replicated using other types of dysplasia in IBD. SLC12A2 could be a potential biomarker of inflammation-associated dysplasia. [less ▲]

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See detailIdentification of proteins discriminating inflammation induced dysplasia from simple inflammation in ulcerative colitis by laser capture microdissection and label free proteomics – a pilot study
Merli, Angela-Maria ULg; QUESADA-CALVO, Florence ULg; MASSOT, Charlotte ULg et al

Poster (2017, February 01)

Chronic colonic inflammation in ulcerative colitis (UC) may induce dysplasia, which can itself progress and transform into neoplasia. Diagnosis of dysplasia in UC remains difficult particularly when ... [more ▼]

Chronic colonic inflammation in ulcerative colitis (UC) may induce dysplasia, which can itself progress and transform into neoplasia. Diagnosis of dysplasia in UC remains difficult particularly when tissue inflammation is present. The aim of this retrospective pilot study was to highlight proteins specifically associated with inflammation induced dysplasia in UC. We performed a pilot experiment on 15 Formalin-Fixed, Paraffin-Embedded (FFPE) samples isolated from 5 cases of UC patients with a Polypoïd Pedunculated dysplasia (UC-PP). We compared the proteomes of the UC-PP, the inflammatory (UC-I) and the normal (UC-NL) tissues of each patient. We performed Laser Capture Microdissection (LCM) in order to collect only epithelial cells, avoiding inflammatory infiltrating ones. Label free proteomic analysis using a 2D-nanoUPLC coupled with a hybrid Quadrupole-Orbitrap was applied, as well as differential analysis on the paired samples. Immunohistochemistry (IHC) characterisation of one of the selected proteins of interest was used for validation. Out of 985 quantified proteins, 7 were found significantly more abundant in UC-PP compared to UC-I tissues, with 6 being only detected in UC-PP using proteomics. One of these is Solute Carrier Family 12 member 2 (SLC12A2), also known as Na-K-2Cl co-transporter 1 (NKCC1), a protein involved in ionic balance, in T-cell migration promotion and in some features involved in cancer development like proliferation, migration or invasion. IHC results obtained were in correlation with proteomic results and showed that SLC12A2 was more abundant in UC-PP tissue than in UC-I and UC-NL tissues, with a signal clearly delimiting the dysplastic region from the surrounding inflammatory tissue. This pilot experiment shows a different proteomic profile in inflammation-associated dysplasia and simple inflammation. This should be replicated using other types of dysplasia in IBD. SLC12A2 could be a potential biomarker of inflammation-associated dysplasia. [less ▲]

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See detailHigh-throughput expression of animal venom toxins in Escherichia coli to generate a large library of oxidized disulphide-reticulated peptides for drug discovery
Turchetto; Sequeira, Ana Filipa; Ramond, Laurie et al

in Microbial Cell Factories (2017), 16(6), 1-15

Animal venoms are complex molecular cocktails containing a wide range of biologically active disulphide-reticulated peptides that target, with high selectivity and efficacy, a variety of membrane ... [more ▼]

Animal venoms are complex molecular cocktails containing a wide range of biologically active disulphide-reticulated peptides that target, with high selectivity and efficacy, a variety of membrane receptors. Disulphide-reticulated peptides have evolved to display improved specificity, low immunogenicity and to show much higher resistance to degradation than linear peptides. These properties make venom peptides attractive candidates for drug development. However, recombinant expression of reticulated peptides containing disulphide bonds is challenging, especially when associated with the production of large libraries of bioactive molecules for drug screening. To date, as an alternative to artificial synthetic chemical libraries, no comprehensive recombinant libraries of natural venom peptides are accessible for high-throughput screening to identify novel therapeutics. RESULTS: In the accompanying paper an efficient system for the expression and purification of oxidized disulphide-reticulated venom peptides in Escherichia coli is described. Here we report the development of a high-throughput automated platform, that could be adapted to the production of other families, to generate the largest ever library of recombinant venom peptides. The peptides were produced in the periplasm of E. coli using redox-active DsbC as a fusion tag, thus allowing the efficient formation of correctly folded disulphide bridges. TEV protease was used to remove fusion tags and recover the animal venom peptides in the native state. Globally, within nine months, out of a total of 4992 synthetic genes encoding a representative diversity of venom peptides, a library containing 2736 recombinant disulphide-reticulated peptides was generated. The data revealed that the animal venom peptides produced in the bacterial host were natively folded and, thus, are putatively biologically active. CONCLUSIONS: Overall this study reveals that high-throughput expression of animal venom peptides in E. coli can generate large libraries of recombinant disulphide-reticulated peptides of remarkable interest for drug discovery programs. [less ▲]

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See detailProteomic response of Macrobrachium rosenbergii hepatopancreas exposed to chlordecone: Identification of endocrine disruption biomarkers?
Lafontaine, Anne ULg; Baiwir, Dominique ULg; Joaquim-Justo, Célia ULg et al

in Ecotoxicology and Environmental Safety (2017)

The present work is the first study investigating the impacts of chlordecone, an organochlorine insecticide, on the proteome of the decapod crustacean Macrobrachium rosenbergii, by gel-free proteomic ... [more ▼]

The present work is the first study investigating the impacts of chlordecone, an organochlorine insecticide, on the proteome of the decapod crustacean Macrobrachium rosenbergii, by gel-free proteomic analysis of the hepatopancreas protein expression variations in organisms exposed to three environmental relevant concentrations of chlordecone (i.e. 0.2, 2 and 20 μg/L). Results revealed that 62 proteins were significantly up- or down-regulated in exposed prawns compared to controls. Most of these proteins are involved in important physiological processes such as ion transport, defense mechanisms and immune system, cytoskeleton dynamics, or protein synthesis and degradation. Moreover, it appears that 6% of the deregulated protein are involved in the endocrine system and in the hormonal control of reproduction or development processes of M. rosenbergii (e.g. vitellogenin, farnesoic acid omethyltransferase). These results indicate that chlordecone is potentially an endocrine disruptor compound for decapods, as already observed in vertebrates. These protein modifications could lead to disruptions of growth and reproduction of M. rosenbergii, and therefore of the fitness population on the long-term. Besides, these disrupted proteins could be suggested as biomarkers of exposure for endocrine disruptions in invertebrates. However, further investigations are needed to complete understanding of action mechanisms of chlordecone on proteome and endocrine system of crustaceans. [less ▲]

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See detailProteomic signatures reveal a dualistic and clinically relevant classification of anal canal carcinoma
Herfs, Michael ULg; Longuespée, Rémi ULg; Quick, Charles et al

in Journal of Pathology (The) (2017), 241

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See detailEcotoxicoproteomic assessment of the functional alterations caused by chronic metallic exposures in gammarids
Gismondi, Eric ULg; Thomé, Jean-Pierre ULg; Urien, Nastassia et al

in Environmental Pollution (2017)

Very few ecotoxicological studies have been performed on long-term exposure under controlled conditions, hence limiting the assessment of the impact of chronic and diffuse chemical pressures on the health ... [more ▼]

Very few ecotoxicological studies have been performed on long-term exposure under controlled conditions, hence limiting the assessment of the impact of chronic and diffuse chemical pressures on the health of aquatic organisms. In this study, an ecotoxicoproteomic approach was used to assess the integrated response and possible acclimation mechanisms in Gammarus fossarum following chronic exposures to Cd, Cu or Pb, at environmentally realistic concentrations (i.e. 0.25, 1.5 and 5 µg/L respectively). After 10-week exposure, changes in protein expression were investigated in caeca of control and exposed males. Gel-free proteomic analyses allowed for the identification of 35 proteins involved in various biological functions, for which 23 were significantly deregulated by metal exposures. The protein deregulation profiles were specific to each metal, providing evidence for metal-specific action sites and responses of gammarids. Among the tested metals, Cu was the most toxic in terms of mortality, probably linked with persistent oxidative stress. Moulting and osmoregulation were the major biological functions affected by Cu in the long-term. In Pb-exposed gammarids, significant deregulations of proteins involved in immune response and cytoskeleton were observed. Reproduction appears to be strongly affected in gammarids chronically exposed to Cd or Pb. Besides, modified expressions of several proteins involved in energy transfer and metabolism highlighted important energetic reshuffling to cope with chronic metal exposures. These results support the fact that metallic pressures induce a functional and energetic cost for individuals of G. fossarum with potential repercussions on population dynamics. Furthermore, this ecotoxicoproteomic study offers promising lines of enquiry in the development of new biomarkers that could make evidence of long-term impacts of metals on the health of organisms. [less ▲]

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See detailMyoferlin is a novel exosomal protein and functional regulator of cancer-derived exosomes
Blomme, Arnaud; Fahmy, Karim; Peulen, Olivier ULg et al

in Oncotarget (2016)

Exosomes are communication mediators participating in the intercellular exchange of proteins, metabolites and nucleic acids. Recent studies have demonstrated that exosomes are characterized by a unique ... [more ▼]

Exosomes are communication mediators participating in the intercellular exchange of proteins, metabolites and nucleic acids. Recent studies have demonstrated that exosomes are characterized by a unique proteomic composition that is distinct from the cellular one. The mechanisms responsible for determining the proteome content of the exosomes remain however obscure. In the current study we employ ultrastructural approach to validate a novel exosomal protein myoferlin. This is a multiple C2-domain containing protein, known for its conserved physiological function in endocytosis and vesicle fusion biology. Emerging studies demonstrate that myoferlin is frequently overexpressed in cancer, where it promotes cancer cell migration and invasion. Our data expand these ndings by showing that myoferlin is a general component of cancer cell derived exosomes from different breast and pancreatic cancer cell lines. Using proteomic analysis, we demonstrate for the rst time that myoferlin depletion in cancer cells leads to a signi cantly modulated exosomal protein load. Such myoferlin-depleted exosomes were also functionally de cient as shown by their reduced capacity to transfer nucleic acids to human endothelial cells (HUVEC). Beyond this, myoferlin-depleted cancer exosomes also had a signi cantly reduced ability to induce migration and proliferation of HUVEC. The present study highlights myoferlin as a new functional player in exosome biology, calling for novel strategies to target this emerging oncogene in human cancer. [less ▲]

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See detailAccurate drift time determination by traveling wave ion mobility spectrometry: The concept of the diffusion calibration
Kune, Christopher ULg; Far, Johann ULg; De Pauw, Edwin ULg

in Analytical Chemistry (2016), 88

Ion mobility spectrometry (IMS) is a gas phase separation technique which relies on differences in collision cross section (CCS) of ions. Ionic clouds of unresolved conformers overlap if the CCS ... [more ▼]

Ion mobility spectrometry (IMS) is a gas phase separation technique which relies on differences in collision cross section (CCS) of ions. Ionic clouds of unresolved conformers overlap if the CCS difference is below the instrumental resolution expressed as CCS/ΔCCS. The experimental arrival time distribution (ATD) peak is then a superimposition of the various contributions weighted by their relative intensities. This paper introduces a strategy for accurate drift time determination using traveling wave ion mobility spectrometry (TWIMS) of poorly resolved or unresolved conformers. This method implements through a calibration procedure the link between the peak full width at half maximum (FWHM) and the drift time of model compounds for wide range of settings for wave heights and velocities. We modified a Gaussian equation which achieves the deconvolution of ATD peaks where the FWHM is fixed according to our calibration procedure. The new fitting Gaussian equation only depends on two parameters: The apex of the peak (A) and the mean drift time value (μ). The standard deviation parameter (correlated to FWHM) becomes a function of the drift time. This correlation function between μ and FWHM is obtained using the TWIMS calibration procedure which determines the maximum instrumental ion beam diffusion under limited and controlled space charge effect using ionic compounds which are detected as single conformers in the gas phase. This deconvolution process has been used to highlight the presence of poorly resolved conformers of crown ether complexes and peptides leading to more accurate CCS determinations in better agreement with quantum chemistry predictions [less ▲]

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See detailSupramolecular influence on cis–trans isomerization probed by ion mobility spectrometry
Czerwinska, Izabella; Kulesza, Alexander; Choi, Changmin et al

in Physical Chemistry Chemical Physics [=PCCP] (2016), 18

We used tandem ion mobility spectrometry measurements to investigate how the photo-isomerization of a chromophore (a methylpyridinium derivative) is affected by the complexation with a crown ether. A ... [more ▼]

We used tandem ion mobility spectrometry measurements to investigate how the photo-isomerization of a chromophore (a methylpyridinium derivative) is affected by the complexation with a crown ether. A dramatic blue-shift of the photo-isomerization spectrum was observed upon complexation, which could be well reproduced by ab initio calculations. Our results support that the observed changes in the photo-physical properties of the chromophore originate from the charge-solvation of its pyridinium moiety by the host cage. [less ▲]

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See detailMyoferlin regulates cellular lipid metabolism and promotes metastases in triple-negative breast cancer
Blomme, Arnaud; Costanza, Brunella ULg; De Tullio, Pascal ULg et al

in Oncogene (2016)

Myoferlin is a multiple C2-domain-containing protein that regulates membrane repair, tyrosine kinase receptor function and endocytosis in myoblasts and endothelial cells. Recently it has been reported as ... [more ▼]

Myoferlin is a multiple C2-domain-containing protein that regulates membrane repair, tyrosine kinase receptor function and endocytosis in myoblasts and endothelial cells. Recently it has been reported as overexpressed in several cancers and shown to contribute to proliferation, migration and invasion of cancer cells. We have previously demonstrated that myoferlin regulates epidermal growth factor receptor activity in breast cancer. In the current study, we report a consistent overexpression of myoferlin in triple-negative breast cancer cells (TNBC) over cells originating from other breast cancer subtypes. Using a combination of proteomics, metabolomics and electron microscopy, we demonstrate that myoferlin depletion results in marked alteration of endosomal system and metabolism. Mechanistically, myoferlin depletion caused impaired vesicle traffic that led to a misbalance of saturated/unsaturated fatty acids. This provoked mitochondrial dysfunction in TNBC cells. As a consequence of the major metabolic stress, TNBC cells rapidly triggered AMP activated protein kinase-mediated metabolic reprogramming to glycolysis. This reduced their ability to balance between oxidative phosphorylation and glycolysis, rendering TNBC cells metabolically inflexible, and more sensitive to metabolic drug targeting in vitro. In line with this, our in vivo findings demonstrated a significantly reduced capacity of myoferlin-deficient TNBC cells to metastasise to lungs. The significance of this observation was further supported by clinical data, showing that TNBC patients whose tumors overexpress myoferlin have worst distant metastasis-free and overall survivals. This novel insight into myoferlin function establishes an important link between vesicle traffic, cancer metabolism and progression, offering new diagnostic and therapeutic concepts to develop treatments for TNBC patients. [less ▲]

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See detailAccurate drift time determination by traveling wave ion mobility spectrometry: The concept of the diffusion calibration
Kune, Christopher ULg; Far, Johann ULg; De Pauw, Edwin ULg

Conference (2016, October 18)

Ion mobility spectrometry (IMS) is a gas phase separation technique which relies on differences in the collisional cross section (CCS) of ions. Ionic clouds of unresolved conformers overlapped if the CCS ... [more ▼]

Ion mobility spectrometry (IMS) is a gas phase separation technique which relies on differences in the collisional cross section (CCS) of ions. Ionic clouds of unresolved conformers overlapped if the CCS difference is below the instrumental resolution expressed as Ω/ΔΩ. The experimental arrival time distribution (ATD) peak is then a superimposition of the various contributions weighted by their relative intensities. We have developed a strategy for accurate drift time determination using traveling wave ion mobility spectrometry (TWIMS) of poorly and unresolved conformers. This method implements through a calibration procedure the link between the peak full width at half maximum (FWHM) and the drift time of model compounds for wide range of settings for wave heights and velocities. We modified a Gaussian equation which achieves the deconvolution of ATD peaks where the FWHM is fixed according to our calibration procedure. The new fitting Gaussian equation only depends on two parameters: The apex of the peak (A) and the mean drift time value (µ). The standard deviation parameter (correlated to FWHM) becomes a function of the drift time. This correlation function between µ and FWHM is obtained using the TWIMS calibration procedure which determines the maximum instrumental ion beam diffusion using ionic compounds which are detected as single conformers in the gas phase. This deconvolution process has been used to highlight the presence of poorly resolved conformers for couples of crown ethers and peptides leading to CCS determination in better agreement with quantum chemistry predictions. [less ▲]

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See detailThe concept of the diffusion calibration for accurate drift time measurement by traveling wave ion mobilty
Kune, Christopher ULg; Far, Johann ULg; De Pauw, Edwin ULg

Poster (2016, October 13)

Ion mobility spectrometry (IMS) is a gas phase separation technique which relies on differences in the collisional cross section (CCS) of ions. Ionic clouds of unresolved conformers overlapped if the CCS ... [more ▼]

Ion mobility spectrometry (IMS) is a gas phase separation technique which relies on differences in the collisional cross section (CCS) of ions. Ionic clouds of unresolved conformers overlapped if the CCS difference is below the instrumental resolution expressed as Ω/ΔΩ. The experimental arrival time distribution (ATD) peak is then a superimposition of the various contributions weighted by their relative intensities. We have developed a strategy for accurate drift time determination using traveling wave ion mobility spectrometry (TWIMS) of poorly and unresolved conformers. This method implements through a calibration procedure the link between the peak full width at half maximum (FWHM) and the drift time of model compounds for wide range of settings for wave heights and velocities. We modified a Gaussian equation which achieves the deconvolution of ATD peaks where the FWHM is fixed according to our calibration procedure. The new fitting Gaussian equation only depends on two parameters: The apex of the peak (A) and the mean drift time value (µ). The standard deviation parameter (correlated to FWHM) becomes a function of the drift time. This correlation function between µ and FWHM is obtained using the TWIMS calibration procedure which determines the maximum instrumental ion beam diffusion using ionic compounds which are detected as single conformers in the gas phase. This deconvolution process has been used to highlight the presence of poorly resolved conformers for couples of crown ethers and peptides leading to CCS determination in better agreement with quantum chemistry predictions. [less ▲]

Detailed reference viewed: 38 (4 ULg)