Dissertations / Theses on the topic 'Protéine (IPP)'
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Alleman, Cécile. "Accès synthétique au châssis [5-8-5] de la fusicoccine-A pour la synthèse d’analogues simplifiés en vue d'étudier les interactions protéine-protéine." Electronic Thesis or Diss., Université de Rennes (2023-....), 2023. http://www.theses.fr/2023URENS090.
In biological media, protein-protein interactions (PPI) are of huge importance, as they allow the regulation of many cellular events. PPI classically involve two partners: an adapter protein and its effector protein(s) regulated either in a positive or a negative manner. Inhibition of PPI has thus been considered as a solid therapeutic approach. On the other hand, stabilization of PPI remains scarcely investigated, but may lead to new promising approaches. This project focuses on the 14-3-3 family adapter protein which interacts with more than 200 protein partners. Among them, p53 protein is subjected to a lot of studies as this tumor suppressor protein regulates multiple biological processes (DNA repair, apoptosis). However, those major functions appear to be silenced in most cancer cases, thus allowing tumor cells proliferation. Some studies have shown that stabilization of the 14-3-3/p53 pair with the help of a molecular glue permitted to restore tumor suppressor activity of p53. Among the examined molecular glues, the fusicoccin-A (FC-A) natural product is shown to lodge in the valley formed by 14-3-3 and increases stabilization of the 14-3-3/p53 interaction. In this context, to enlarge the p53/14-3-3 molecular glue library, this project focuses on the access to simplified FC-A analogs through the synthesis of tricyclic scaffold. [6-8-5] analogs from an aromatic substrate are envisaged, as well as [5-8-5] analogs from a cyclopentane derivative, closer to the target structure. Various strategies have been explored in order to access these analogs
Becker, Emmanuelle. "Prédictions bioinformatiques des propriétés des domaines de reconnaissance peptidique." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2007. http://tel.archives-ouvertes.fr/tel-00553471.
Kuenemann, Mélaine. "Etude de l'espace chimique des modulateurs d'interactions protéine-protéine et leurs applications en chimie biologie." Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCC215.
Protein-protein interactions (PPI) represent a wealth of potential therapeutic targets. However targeting them with synthetic compounds represent a major challenge. The aim of this thesis was to find a way to overcome these challenges by studying the physicochemical profile of PPI inhibitors (aka chemical space). We firstly manually collected structures, pharmacological and physicochemical profiles of inhibitors of PPI (iPPI) in a database named iPPI-DB. Then, we identified new iPPI properties to favour and that did not preclude further drug development. Indeed, 4 descriptors were found specific to iPPI and that do not rely on the hydrophobicity and on the size. They represent either the 3D shape of the compounds or the distribution of their hydrophobic/hydrophilic interacting regions. This opens new ways to design and select iPPI. In a second analysis, we further validated these properties on larger datasets and address the disparity between PPI families. We could demonstrate that comparable classes of PPI targets can identified using separately their target- or their ligand-space. This analysis may help to prioritize the desired physicochemical properties of iPPI using class-specific profiles. Finally, using a combination virtual screening and cell viability assay, we were able to identify 6 compounds that inhibit the interaction between TRAIL and DR5 implied in HIV (human immunodeficiency virus)
Chamoun, Jean. "Contribution du couplage CE-ICP/MS dans l'étude des interactions métals-protéine non-covalentes." Université Louis Pasteur (Strasbourg) (1971-2008), 2005. http://www.theses.fr/2005STR13090.
The screening of metal/protein interactions using CE coupled to ICP/MS was investigated. The development of this new analytical tool requires, besides the hyphenation of the two techniques, both an efficient separation of the proteins and a sensitive detection of metals. The optimization of the electrophoretic separation of a protein-test mixture led to the use of a borate buffer, pH 9. 2, which both minimizes adsorption and allows the separation of all proteins’ mixture with a good migration times reproducibility. The hyphenation between capillary electrophoresis and ICP/MS was performed using a sheath flow interface. The optimization of parameters, such as coolant, auxiliary and nebulizer gases, composition and flowrate of the sheath flow solution and position of the capillary in the nebulizer was carried out in order to obtain the best detection sensitivity and separation efficiency. However, this type of interface involves important samples dilutions, which led us to develop an on-line preconcentration technique in order to improve the detection limits. The detection limits calculated for the copper and zinc contained in the carbonic anhydrase, the less efficiently concentrated protein, showed an improvement of the detection limits in CE-ICP/MS of 6 times for copper and 5 times for zinc. CE-ICP/MS was then used in the study of the interactions of three transition metals (Cd, Co and Ni) with a mixture of proteins made of metalloproteins and major blood serum proteins. These studies revealed a similar behavior of cobalt and nickel, completely different from that of cadmium. In the case of the metalloproteins, hyphenated CE-ICP/MS allowed to identify the probable nature of the interaction sites. Moreover, this method allowed studies on the relative affinity of various metals with a mixture of proteins. The dissociative aspect of the separation was also exploited in order to obtain kinetic data which allowed the access to the dissociation constants of the complexes and in certain cases, highlighted the presence of multiple interaction sites. Finally, the technique was applied to so-called “hard cations”: lanthanides and uranyl ion (UO22+). The first results showed a massive adsorption of these cations on the capillaries surface. Nevertheless, the studies, carried out on a mixture of six proteins, previously identified as uranium-targets, showed that four of them interact with the uranium, among which albumin and transferrin
Vijayakumar, Jeshlee Cyril. "Rôle du domaine de type prion de Imp dans la régulation des granules RNP neuronaux." Electronic Thesis or Diss., Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4099.
Eukaryotic mRNAs are bound by RNA Binding Proteins (RBP) and packaged into diverse range of macromolecular assemblies named RNP granules. In neurons, transport RNP granules are implicated in the transport of specific mRNAs to axons or dendrites, and in their local translation in response to external cues. Although little is known about the assembly and regulation of these granules in vivo, growing evidence indicates that the presence of Prion Like domains (PLD) within RBPs favours multivalent protein–protein and protein-RNA interactions, promoting the transition of soluble complexes into RNP granules. The conserved RBP Imp is as a core component of RNP granules that are actively transported to axons upon neuronal remodelling in Drosophila. Furthermore, Imp function was shown to be required for axonal remodelling during Drosophila nervous system maturation. Analyses of the domain architecture of the Imp protein revealed that, in addition to four RNA binding domains (RBD), Imp contains a Cterminal domain showing a striking enrichment in Glutamines and Serines, which is one of the characteristics of a PLD. During my PhD, I explored the function of the PLD in the context of granule assembly and transport. In cultured cells, I observed that Imp granules assembled in the absence of the PLD, however their number and size were increased. Proteins with scrambled PLD sequence accumulated in granules of normal size and number, implying that the degree of disorder of this domain, and not its sequence, is essential for granule homeostasis. Moreover, FRAP experiments, performed on cultured cells and in vivo, revealed that Imp PLD is important to maintain the turnover of these granules. In vivo, this domain is both necessary and sufficient for efficient transport of Imp granules to axons. These defects are associated with a reduction on the number of motile granules in axons. Furthermore, mutant forms lacking the PLD do not rescue the axon remodelling defects observed upon imp loss of function. Finally, a swapping experiment in which I moved Imp PLD from the C-terminus to the N-terminus of the protein revealed that the functions of Imp PLD in granule transport and homeostasis are uncoupled, and that PLD-dependent modulation of Imp granule properties is dispensable in vivo. Together, my results show that Imp PLD of is not required for the assembly of RNP granules, but rather regulates granule number and dynamics. Furthermore, my work uncovered an unexpected in vivo function for a PLD in axonal transport and remodelling during nervous system maturation
Vijayakumar, Jeshlee Cyril. "Rôle du domaine de type prion de Imp dans la régulation des granules RNP neuronaux." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4099/document.
Eukaryotic mRNAs are bound by RNA Binding Proteins (RBP) and packaged into diverse range of macromolecular assemblies named RNP granules. In neurons, transport RNP granules are implicated in the transport of specific mRNAs to axons or dendrites, and in their local translation in response to external cues. Although little is known about the assembly and regulation of these granules in vivo, growing evidence indicates that the presence of Prion Like domains (PLD) within RBPs favours multivalent protein–protein and protein-RNA interactions, promoting the transition of soluble complexes into RNP granules. The conserved RBP Imp is as a core component of RNP granules that are actively transported to axons upon neuronal remodelling in Drosophila. Furthermore, Imp function was shown to be required for axonal remodelling during Drosophila nervous system maturation. Analyses of the domain architecture of the Imp protein revealed that, in addition to four RNA binding domains (RBD), Imp contains a Cterminal domain showing a striking enrichment in Glutamines and Serines, which is one of the characteristics of a PLD. During my PhD, I explored the function of the PLD in the context of granule assembly and transport. In cultured cells, I observed that Imp granules assembled in the absence of the PLD, however their number and size were increased. Proteins with scrambled PLD sequence accumulated in granules of normal size and number, implying that the degree of disorder of this domain, and not its sequence, is essential for granule homeostasis. Moreover, FRAP experiments, performed on cultured cells and in vivo, revealed that Imp PLD is important to maintain the turnover of these granules. In vivo, this domain is both necessary and sufficient for efficient transport of Imp granules to axons. These defects are associated with a reduction on the number of motile granules in axons. Furthermore, mutant forms lacking the PLD do not rescue the axon remodelling defects observed upon imp loss of function. Finally, a swapping experiment in which I moved Imp PLD from the C-terminus to the N-terminus of the protein revealed that the functions of Imp PLD in granule transport and homeostasis are uncoupled, and that PLD-dependent modulation of Imp granule properties is dispensable in vivo. Together, my results show that Imp PLD of is not required for the assembly of RNP granules, but rather regulates granule number and dynamics. Furthermore, my work uncovered an unexpected in vivo function for a PLD in axonal transport and remodelling during nervous system maturation
Pinet, Louise. "Structural and functional investigation of the C-terminal intrinsically disordered fragment of ErbB2." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS375/document.
ErbB2/HER2 is a receptor tyrosine kinase of the EGFR (ErbB1) family overexpressed in 20% of breast cancers and associated to a particularly aggressive form of the disease. ErbB receptors are only active upon dimerization that enables phosphorylation of their C-terminal tail by their tyrosine kinase domain. Phosphorylation then triggers interaction with adaptor proteins and activation of signaling pathways, mainly Ras/MAPK and Akt/PI3K. Those pathways control cell proliferation, motility and resistance to apoptosis. Contrary to ErbB1/3/4, ErbB2 can dimerize without any ligand. Understanding other mechanisms of regulation of its tyrosine phosphorylation and of its interactions is thus particularly interesting.ErbB2 structure and function have been extensively studied. This has led to the development of several FDA-approved targeted drugs, that are effective but to which resistance occurs, amongst which the Trastuzumab antibody that targets ErbB2 extracellular domain. The C-terminal tail of ErbB2 (CtErbB2) has been widely ignored in these studies. Since it is intrinsically disordered, the concepts and tools to study it have only emerged in the last few years.In the present work, I have performed the structural and dynamic study of CtErbB2. I showed that despite its lack of any stable structure, this proline-rich region exhibits several transient secondary structures and a long-range contact that might participate in the regulation of its intra- and inter-molecular interactions. Then, I characterized the adaptor protein Grb2, which is a partner of ErbB2 that is essential for the activation of the MAPK pathway. The solution organization of the domains of this modular protein in its apo-form was unknown so far. I also studied the interaction between Grb2 and CtErbB2, showing that in addition to the known SH2-phosphotyrosine interaction, a polyproline motif of CtErbB2 binds to the N-terminal SH3 domain of Grb2. Finally, I implemented several strategies to phosphorylate CtErbB2 tyrosines, to study more extensively the effect of phosphorylation on the whole tail
Boudoukha, Selim. "Étude de la régulation post-transcriptionnelle de l’expression des gènes par la protéine de liaison à l’ARN IMP-2 au cours de la myogenèse." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA11T095/document.
The RNA-binding proteins IMPs (IGF-II mRNA binding protein) first discovered in rhabdomyosarcoma cells (RMS) are expressed during embryonic development but their expression is decreased in adult tissues.We showed that IMPs and particularly IMP-2 are strongly expressed in mouse myoblatsts, during early regeneration of skeletal muscle in vivo and in and RMS. IMP-2 loss of function experiments using siRNA have shown that IMP-2 is necessary for microtubules stability(MTs), cell motility and invasion of myoblasts and RMS.Expression of IMP-2 specifically increases MTs stability by an enrichment of detyrosinated tubulin Glu-tubulin. Detyrosination is indispensable for myogenic differentiation and plays substantial role in tumor growth. Additionaly, MTs stabilization play an important role in focal adhesion remodeling, in cytoskeleton integrity, cell adhesion and cell motility.To get new insight into molecular mechanism underlying the function of IMP-2 in MTs stability and cell motility, full ranscriptome analysis was performed between IMP-2 knockdown (KD) myoblasts and control myoblatsts. We have further shown that IMP-2 controls the mRNA levels of many important mediators of cell adhesion such as PINCH-2, as well as multiple cytoskeleton remodeling, such as MuRF-3.We have identified a number of functionally relevant protein partners of IMP-2.Moreover subsequent RNAi screens have revealed the importance of IMP-2 regulated transcripts involved in cell motility and cell adhesion In conclusion, we show that IMP-2 dependent regulation of mRNA such as MuRF3 and PINCH2 largely contributes to the motility –deficient in IMP-2 KD cells. Moreover these results indicate clearly, that further analysis of IMP2 protein partners and RNA targets regulated by IMP-2 will help to characterized the function of IMP-2 and to propose a model of IMP-2 transcriptional regulation of gene expression in myoblasts and RMS cells
Bonneau, Benjamin. "Implication des protéines de la famille Bcl-2 dans la régulation des flux calciques au cours du développement embryonnaire précoce du poisson zèbre." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10155/document.
Apoptosis is a key cellular process for tissue homeostasis. Apoptotic cell death is under control of Bcl-2 family proteins which regulate outer mitochondrial membrane permeability. However, beyond their role in apoptosis, Bcl-2 family proteins are also involved in other cellular processes such as cell cycle or metabolism. In our laboratory we are interested in non-apoptotic functions of Bcl-2 family proteins in embryonic development. Using zebrafish model we have shown that Bcl-2 proteins control different processes during early development thanks to their ability to regulate calcium homeostasis. Indeed, we have shown that the anti-apoptotic protein Nrz participates in actin cytoskeleton remodeling during epiboly by regulating cytosolic calcium concentration via an interaction with the IP3 receptor (IP3R). We have also demonstrated that Nrz decreases calcium release from the endoplasmic reticulum by inhibiting IP3 fixation on its receptor. We have furthermore identified a new pro-apoptotic member of Bcl-2 family, Bcl-wav which is expressed only in fish and frogs. This protein regulates mitochondrial calcium homeostasis by interacting with VDAC. We have moreover shown that this activity is essential for convergence and extension movements during early zebrafish development
Chevreux, Sylviane. "Spéciation directe de métalloprotéines séparées sur gels d'électrophorèse : analyses XAS de la superoxyde dismutase et ICP-MS de protéines arseniées." Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13880/document.
Metalloproteomic is a new discipline which ally proteome determination and the identification, location and speciation of inorganic elements bound to proteins. The low concentration of these heteroelements and sometimes their non-covalent binding to proteins need to set up analytical tools enabling the protein separation at high resolution, without any modification of the bond protein-heteroelement, and the protein speciation with a technique presenting a low detection limit. The aim of this study is to set up such protocols on two proteic systems, depicting the two main protein-heteroelement interactions: forming of metallic complexes or covalent bonds. First, we studied copper, zinc superoxide dismutase (CuZnSOD), mutants of this protein being involved in a neurodegenerative disease, the amyotrophic lateral sclerosis. Isoelectric point isoforms of wild-type and mutant CuZnSOD, separated on electrophoresis gel, were analyzed using X-ray Absorption Spectroscopy (XAS). XAS experiments on proteins separated on electrophoresis gel were performed for the first time. Data analysis at Zn K-edge demonstrated the feasibility of this technique and the ones at the Cu K-edge highlighted oxidation states Cu(I) et Cu(II) differences between isoforms. Second, we studied arsenic metabolisation to understand its carcinogenicity. Proteins extracted from hepatic cells exposed to arsenic were separated using gel electrophoresis and liquid chromatography. Samples analysis using mass spectrometry highlighted three proteic species which bind arsenic
Meyer, Sandra. "Caractérisation des domaines N-terminal et de liaison à l'ADN du récepteur des androgènes par des approches biophysiques." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAJ091/document.
My PhD project is at the boundary between biology and biophysic. Methods used include nuclear magnetic resonance (NMR), small ange X-ray scattering (SAXS), circular dichroïsm (CD) and fluorescence spectroscopy. The androgen receptor (AR) DNA binding domain (DBD) and its interaction with DNA was studied in a first part. A mutation in the DBD leads to a modified DNA recognition by the mutant compared to the wild-type. Our results indicate changes in dynamic of the mutant receptor that leads to the homodimer destabilisation.The second part of my project aim to establish a link between sequence and function of the AR N terminal domain (NTD).As described in literature, this region is involved in the activity of the receptor and is also an intrinsically disordered protein (IDP). The results obtained during my thesis indicate that this region is involved in transient contact with the DBD. This suggest an allosteric coupling between the DBD and the neighboring residues on the NTD.This coupling modifies the conformational ensemble accessible to the NTD by stabilizing a α-helix conformation
Friboulet, Luc. "Contribution de la protéine c-IAP2 à l'oncologenèse des carcinomes nasopharryngés et d'autres tumeurs malignes : Modulation des effets biologiques de TLR3." Paris 11, 2009. http://www.theses.fr/2009PA11T010.
Huynh, Thi Ngoc Suong. "Stratégie analytique combinant électrophorèse capillaire et ICP/MS pour la caractérisation des cibles biologiques de l'uranium." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS052/document.
Identification of proteins targeted by uranium is of major concern in the determination of uranium toxicity and the development of decorporation agents. In this study, we examine the capabilities offered by hyphenated CE - ICP/MS for the detection of protein-uranium complexes. With judicious separation conditions, it is possible to obtain the uranium distribution in samples of moderate complexity. This approach was validated by using known proteins targeted by uranium (individually or in simple mixtures). Apparent equilibrium constants were determined with an accuracy similar to the ones obtained by biophysical methods. The interest of using this hyphenation was illustrated through diverse applications. The direct analysis of human serum confirmed the strong involvement of fetuin, a human glycoprotein, in the uranium blood distribution. Last but not least, the integration of this hyphenation into a multi-techniques approach (ICP/MS, DLS, CE-ICP/MS) allowed evaluating the influence of uranium on the formation of calciprotein particles and provided a proof of the preservation of protein-uranium complexes in such conditions
Boudoukha, Selim. "Étude de la régulation post-transcriptionnelle de l'expression des gènes par la protéine de liaison à l'ARN IMP-2 au cours de la myogenèse." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00759640.
Badillo, Aurélie. "Analyses structurales et fonctionnelles de la protéine non-structurale 5A (NS5A) du virus de l’hépatite C." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10239.
NS5A is essential for HCV replication and particle assembly, and constitutes a very promising drug target. However, no clear function has yet been described for NS5A, and structural knowledge remains limited. We characterized the intrinsically disordered nature of NS5A domains D2 and D3, and describe their folding propensity and their overall conformational behaviour by combining different biophysical methods. We also highlighted the structural variability of D2 domain in HCV genotypes, which might be correlated with the disparities observed between genotypes in terms of pathogenesis and efficiency of therapies. The interactions between D2 and D3 with human cyclophilin A (CypA) was analysed by surface plasmon resonance (SPR). We showed that mutations in the D2 domain conferring resistance of HCV replication to CypA inhibitors did not prevent the interaction between D2 and CypA. However, they induce structural perturbations that may affect the kinetics of conformers interconversion of D2. We also showed by SPR that D2 and D3 interact with the of DNA-binding domain of the nuclear receptor FXR (farnesoid X receptor alpha). This interaction reduce the binding of FXR to its DNA target, suggesting an involvement of NS5A in the modulation of the transcriptional activity of FXR. All this data led us to propose a model of the overall structure of NS5A, which provides a useful template for a better understanding of structural and functional properties of this enigmatic protein
Véquaud, Éloïse. "Étude de la réponse des cellules cancéreuses mammaires au ciblage de la Survivine par ARN interférence et inhibition pharmacologique : mise en évidence d'une régulation de la recombinaison homologue par la Survivine." Nantes, 2014. https://archive.bu.univ-nantes.fr/pollux/show/show?id=592390f7-be78-4f21-9982-1e2831fde494.
Survivin has attracted considerable attention as a therapeutic target for anticancer strategies because of its dual role in regulating cell division and apoptosis. Survivin, overexpressed in many cancer, has been consistently identified carrying unfavorable implications for cancer prognosis and linked to aggressive tumor and to inhibition of cell death induced by DNA damaging agents. We thus analyzed functional consequences of Survivin depletion by RNA interference and by use of its expression pharmacological inhibitor, YM155. We first pointed out, in Survivin depleted mammary cancer cell lines, DNA damage occuring, cell division failure and polyploid cells accumulation. We also observed that Survivin depletion decreased the efficiency of DNA repair by Homologous Recombination (HR). We further evidenced that this depletion decreased the transcription of a set of genes involved in HR, (e. G. BRCA1-2, RAD51), in several breast cancer cell lines. Consistent with these results, we confirmed that the protein expression of RAD51 and MUS81 was greatly decreased upon Survivin depletion. Moreover, functionally this depletion sensitizes breast cancer cells to PARP-1 inhibitor. We noted that YM155 did not provide similar cellular effects compared to Survivin depletion, suggesting the existence of other targets. We indeed observed that YM155 induce a dramatic cell death, preferentially in breast cancer cells compared to untransformed cells. Induction of cell death by YM155 was also evidenced in ex vivo organotypic cultures of human primary breast tumors, attesting to its therapeutic interest. Finally, we found out autophagy and NF-kB pathways contribution to YM155 induced cell death
Holste, Angela Sarah. "Développement des méthodes bio analytique pour l’analyse quantitative et qualitative des peptides et protéines marqués par le couplage de la chromatographie et la spectrométrie de masse." Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3004/document.
This PhD thesis was a Cotutelle between the Université de Pau et des Pays de l’Adour (UPPA) in Pau, France and the Christian-Albrechts University (CAU) in Kiel, Germany. In the course of this international collaboration, bio-analytical methods for the quantitative and qualitative analysis of labelled peptides and proteins were developed, which were based on the hyphenation of chromatography with mass spectrometry. Peptides and protein digests were lanthanide labelled using DOTA-based compounds according to an optimised protocol. Separation on the peptide level was performed using IP-RP-nanoHPLC. Complementary data sets were acquired using MALDI-MS for identification and ICP-MS for quantification. In this context, an online precleaning step was developed and implemented in the nanoHPLC separation routine, which allowed for effective removal of excess reagents. This lead to lowered metal backgrounds during ICP-MS measurements and thus better data interpretability, while guarding peptide recovery at a maximum level. An alternative offline purification using solid phase extraction (SPE) resulted in important peptide losses and can be considered unsuitable for quantitative analysis. Additives to the nanoHPLC eluents, such as HFBA and EDTA were tested and not deemed beneficial for the analysis of normal peptide samples. HFBA can be reconsidered for special application on very hydrophilic peptide species. A set of labelled peptides was developed, which due to application of known quantities could be employed for quick and simple quantification of a low complexity digest sample. In addition this peptide set allowed for the reliable superposition of chromatograms, enabling sample comparability especially for complementary ICP-MS and MALDI-MS data. Experiments for application of fsLA-ICP-MS on MALDI-MS target plates were conducted and showed very promising results. For this purpose, samples that were already identified using MALDI-MS were supposed to be remeasured using fsLA-ICP-MS. First quantification attempts on the modified steel target plate were successful and in the range of expectance. Adjusted parameters for MALDI-MS allowed for proper peptide identifications
Mbawala, Augustin. "Contribution à l'étude chimique et structurale des phosphopeptidomannanes parietaux de la levure pichia pastoris IFP 206 cultivée en présence de sources carbonées méthanol (levure très floculante) et glucose (levure peu floculante)." Nancy 1, 1990. http://www.theses.fr/1990NAN10036.
Beltrandi, Matilde. "Characterization of the intrinsically disordered and multimerization regions of the Henipavirus P proteins." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4115.
The objective of my PhD project was the molecular characterization of the P protein from the Nipah and Hendra viruses (BL4) belonging to the Henipavirus genus. The genome is encapsidated by the N that is the substrate for transcription and replication. The polymerase is made up the L and its cofactor the P. The P protein consists of an intrinsically disordered N-terminal domain (PNT), and a C-terminal domain (PCT) made of alternating disordered and ordered domain (PMD or P multimerization domain). I investigated the PMD, PCT and PNT regions, using cross-linking, AUC, CD, SAXS, NMR and molecular modeling. I showed that Hendra and Nipah PMD are a trimeric coiled-coil in solution. The Henipavirus proteins constitute so far the unique examples of a trimeric organization in paramyxoviral P proteins. The PCT is a trimer as well. Using SAXS, I obtained an ensemble description of PNT. To obtain site-specific information that improve SAXS-based models, I undertook the characterization of Hendra PNT by NMR. The latter was divided using the “divide et impera” approach to get four fragments (PNT1,2,3,4). Experiments for the assignment have been performed for PNT1. R1, R2 and NOE were carried out on PNT1,2,3. Altogether the results laid the basis for achieving an atomic-resolution conformational ensemble description of Hendra PNT. This information, combined with structural information that I collected on PCT, PMD and XD, is expected to lead an atomistic ensemble description of the full-length P, which would represent the first, such a description of a paramyxoviral P protein. This detailed structural information will also constitute an asset for rational antiviral approaches
Garat, Anne. "PHARMACOGENETIQUE DES MEDICAMENTS THIOPURINIQUES Implication des enzymes TPMT et IMPDH2 et de la RhoGTPase RAC1." Phd thesis, Université du Droit et de la Santé - Lille II, 2009. http://tel.archives-ouvertes.fr/tel-00439266.
Berardet, Corentin. "Développement de techniques physiques et chimiques pour l’étude et l’inhibition de l’oligomérisation et de l’agrégation de IAPP : intérêt dans le diabète de type II." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS445.
The rising prevalence of type II diabetes, and associated adverse cardiovascular risks, is now considered as a major public health challenge. The aggregation of human islet amyloid polypeptide (hIAPP) is linked to beta-cell degeneration and to the pathogenesis of type II diabetes. The mechanism of hIAPP toxicity and the species involved (oligomers and/or fibrils) are far to be elucidated, although recent studies have shown that early formed species could be the most toxic species. Very few techniques are currently available to monitor in real time this oligomerization and to evaluate inhibitors of this pathological process. During this PhD project, we investigated CE and IMS-MS as potential techniques to monitor in vitro and in real time the oligomerization of hIAPP. A CE-UV method has been developed, which allows the activity evaluation of new inhibitors. An IMS-MS method has also been developed to investigate the interactions formed between hIAPP and the inhibitors. Peptidomimetics inhibitors have been rationally designed and synthesized in order to destabilize beta-sheets structures formed during the oligomerization process of hIAPP. The evaluation of those compounds revealed a relation between their structures and their inhibitory activities. Cellular viability tests are on-going to get more insights on those molecules activity
Allègre-Cultot, Jennifer. "Analyse de la régulation du facteur de transcription E2F1 par cIAP1." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCI013/document.
The cellular inhibitor of Apoptosis 1 (cIAP1) behaves as an E3 ubiquitin ligase and has oncogenic properties. Previously, our team has shown that cIAP1 can regulate the E2F1 transcription factor activity. My research project has been focused on deepening our current knowledge on this interaction. Firstly, we characterized the E2F1-cIAP1 interaction, then we analyzed the regulation of E2F1 by cIAP1 and finally assessed the importance of the cIAP1-E2F1 interaction for the oncogenic properties of cIAP1. I have demonstrated a interaction of E2F1 with the hydrophobic pocket of the BIR3 domain of cIAP1. Moreover, I highlighted that the alpha 1 helix of the BIR3 domain is mandatory for the stability of this pocket. Moreover, we discovered an ubiquitination on lysine 161 and 164 of E2F1 by cIAP1. This ubiquitination is essential for the stability and transcriptional activity of E2F1. Finally, it appears that the cIAP1 BIR1 domain that is required for the interaction with TRAF2 is involved in its oncogenic properties
Garat, Anne. "Pharmacogénétique des médicaments thiopuriniques : implication des enzymes TPMT et IMPDH2 et de la RhoGTPase RAC1." Lille 2, 2009. http://www.theses.fr/2009LIL2S029.
The thiopurine drugs, azathioprine, 6-mercaptopurine and 6-thioguanine, have been used for decades for their cytotoxic and immunosuppressive properties in the treatment of leukemias, chronic inflammatory or autoimmune diseases and in the prevention of allograft rejection. However, some patients treated with conventional doses of these molecules develop very severe side effects. The deficient activity of the thiopurine S-methyltransferase (TPMT), an enzyme involved in thiopurine inactivation, is one of the key factors in the myelotoxicity of these drugs. The determination of the TPMT phenotype by genotyping test is a preventive measure before the initiation of thiopurine therapy and is based on the identification of the most common inactivating mutations of the TPMT gene. First, our study consisted in the functional analysis of four new allelic variants of TPMT, using an heterologous expression system, the yeast S. Cerevisiae. The non-functional character of two of those variants was demonstrated. However, TPMT deficiency explain only about 30 % of cases of thiopurine myelotoxicity, suggesting the existence of other genetic abnormalities affecting other genes involved in the response toward thiopurines. Accordingly, we studied the genetic polymorphism of two other proteins, the inosine monophosphate dehydrogenase type 2 (IMPDH2), a key enzyme in the production of the active metabolites of thiopurine, and the RhoGTPase RAC1, which is one of the pharmacological targets of these molecules. Some of the polymorphisms that we identified in those two genes seem to affect in vitro the expression and / or activity of these proteins and, therefore, could contribute to inter-individual variations of the response to thiopurine
Xu, Yaochun. "Fluorinated Peptidomimetics : Synthesis, Conformational Studies and Evaluation as Amyloid Proteins Aggregation Modulators." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS585/document.
It has been widely recognized that Alzheimer’s disease (AD) represents an unsettling, worldwide challenge for society. By far, there has been no effective cure for AD. Pathologically, AD is characterized by a loss of synapses, an increase in the number of extracellular Abeta plaques and an increase in intracellular aggregated hyperphosphorylated Tau (neurofibrillary tangles). It is commonly believed that AD is primarily linked to oligomerization and fibrillization of amyloid beta peptides, and the soluble Abeta oligomers and fibrils are neurotoxic species.One strategy to reduce the Abeta fibrils is the use of peptides or peptidomimetics to inhibit the Abeta aggregation either by interaction with the Abeta oligomers to prevent its further aggregation into fibrils, or by stabilizing the transient Abeta α-helical conformations to prevent its transition to beta-sheet structures.In the first direction, based on the encouraging results of the glycopeptides containing the polar sugar beta-sheet breaker element to modulate Abeta peptide aggregation and the unique properties of trifluoromethylhydroxyl group, we designed and synthesized pentapeptide mimics with the sequence (Boc) Ala-Val-X-Val-Leu-OMe (X = Ser, Thr, (2S, 3R)-CF3-Thr and (2S, 3S)-CF3-Thr) to interact with the nucleation site of Abeta peptide in its monomeric or oligomeric form so as to disrupt the self-assembly into toxic oligomeric form. Both 2D NMR and molecular modelling studies indicated that these peptides in polar solvent (water and methanol) adopt mainly extended backbone conformations. It is found both experimentally and theoretically that, the (2S, 3S)-CF3-threonine-containing pentapeptides are more extended than the L-serine- and L- threonine-containing pentapeptides. It is also observed that the (2S, 3S)-CF3-Thr pentapeptides have a propensity to self-associate of by forming intermolecular beta-strand contacts. The ability of these pentapeptides to inhibit amyloid fibril formation was evaluated on Abeta1-42 and IAPP peptides by ThT fluorescence assay. It was found that none of these pentapeptides have any inhibition effect in Abeta1-42 peptide and IAPP aggregation. On the contrary, some compounds showed an acceleration effect in IAPP aggregation. Accelerating the aggregation pathways is less intuitive but this strategy has more recently aroused interest. It could be interesting to further study the effect of accelerating IAPP aggregation by complementary techniques.In the other direction, we have assembled novel a CF3-1,4-triazole-based amino acid mimic into homo-oligomers (trimer and tetramer) and peptidomimetics. The fluorinated oligomers were investigated both by NMR conformational studies and molecular modelling simulations. Our preliminary modelling studies predict helical structures with trimer and tetramers of CF3-1,4-disubstituted- 1,2,3- triazole-based amino acid. NMR analysis of tetramer displayed very interesting NOE correlations, indicating a folded structure. The ability of these fluorinated oligomers to modulate the amyloid fibril formation of Abeta1-42 and IAPP peptides were evaluated by ThT fluorescence assay. It was found that trimer was a weak inhibitor of Abeta1-42 aggregation but also a promoter of IAPP aggregation. The tetramer was found able to modulate the aggregation of Abeta1-42 and IAPP but not in a classical inhibition or promotion manner
Nougarede, Adrien. "Molecular basis of BCL2L10/Nrh oncogenic activity in breast cancer." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1192/document.
Apoptosis, also called “Programmed Cell Death”, plays a key role in many biological processes and pathologies. The B-cell lymphoma 2 (Bcl-2) proteins, whose expression is often altered in tumor cells, are the main regulators of apoptosis.Among this family, the actual physiological function of the human apoptosis inhibitor Nrh, also referred to as BCL2L10 or Bcl-B, remains elusive. Although in most healthy tissues the Nrh protein is nearly undetectable, clinical studies have shown that Nrh expression is correlated with poor prognosis in breast and prostate carcinomas. We have shed light on a novel mechanism by which Nrz, the zebrafish ortholog of Nrh, was found to interact with the Ligand Binding Domain (LBD) of the Inositol-1,4,5-triphosphate receptor (IP3R) type-I Ca2+ channel. Indeed, the regulation of IP3Rs-mediated Ca2+ signaling by Nrz was shown to be critical during zebrafish embryogenesis. We used the knowledge gained with the zebrafish model to investigate Nrh function in cancer. We showed that Nrh interacts with the LBD of IP3Rs via its BH4 (Bcl-2 Homology 4) domain, which is critical to regulate intracellular Ca2+ trafficking and cell death. Actually, this interaction seems to be unique among the Bcl-2 family, and sets Nrh as the only Bcl-2 homolog to negatively regulate apoptosis by acting exclusively at the Endoplasmic Reticulum. Furthermore, we showed that disruption of the Nrh/IP3Rs complex primes Nrh-dependent cells to apoptotic cell death and enhances chemotherapy efficiency in breast cancer cell lines.Lastly our results bring a new insight to the role of Nrh regarding chemotherapy resistance
Bucher, Guillaume. "Développements analytiques pour la spéciation de l’uranium dans les branchies du poisson zèbre (Danio rerio) après exposition." Thesis, Pau, 2013. http://www.theses.fr/2013PAUU3044/document.
The objective of this thesis is to study the cellular compartmentalization and the chelation of uranium (U) by cytosolic proteins of gill cells of the zebrafish (Danio rerio, model species in aquatic toxicology) under different direct exposure conditions (chronic vs. acute, 20 and 250 µg.L 1). This study required the development of hyphenated techniques (SEC, IEF off-gel, RP-UHPLC for the separation, ICP-SFMS, ESI-FTMS/MS for the detection) with the main challenges of maintaining the non-covalent U-biomolecule interactions and enhancing sensitivity for the analysis of environmentally relevant samples. After extraction, 24% to 32% of the total U detected in the gills were present in the cytosolic fraction, in which the U distribution on the biomolecules (as a function of their MW and pI) varied depending on the exposure level. Finally, U target biomolecules mapping allowed us (i) to highlight a particular affinity of U for acidic and/or P-containing proteins and (ii) to identify 24 protein candidates for U binding
Marchal-Duval, Emmeline. "Identification de PRRX1 (Paired Related Homeobox Protein-1), un nouveau facteur de transcription impliqué dans la Fibrose Pulmonaire Idiopathique." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC326.
Idiopathic Pulmonary Fibrosis (IPF) is a chronic pulmonary devastating disease, with no current therapeutic available. Fibroblasts are key cells driving fibrogenesis during IPF. From mesenchymal origin, their phenotype regulation is still poorly understood. And among the potential regulators, only few transcription factors (TF) are specific to these cells. Our work demonstrates for the first time, the implication of the mesenchymal TF PRRX1 in the regulation of fibroblast phenotype during IPF development. In vitro, PRRX1 induce proliferation, survival and myofibroblast differentiation. In vivo, the PRRX1 inhibition by antisens strategy lead to attenuate fibrotic lesions and extracellular matrix deposition of collagen, fibronectine, and smooth muscle actin of bleomycin lung mice. Here we identify PRRX1 as a new fibroblast transcription factor regulator during IPF, and inhibit it could be a promising therapeutic
Benadiba, Marcel. "Análise da expressão de proteínas envolvidas no controle do ciclo celular, apoptose, angiogênese, invasão e migração de células C6 in vitro e in vivo, após o tratamento com o ácido g-linolênico (GLA) e com um novo complexo dirutênico contendo Ibuprofeno (Ru-Ibp)." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/42/42134/tde-23032009-131935/.
Gliomas are intracranial tumors of cerebral origin characterized for its rapid growth and resistance to both conventional chemotherapy and radiotherapy. The search for new therapeutics agents with multiple mechanisms of action has identified g-linolenic acid (GLA), nonsteroidal anti-inflammatory drugs (NSAIDs) and ruthenium containing compounds as possible candidates. The aim of this study was to better know the mechanism of action of these drugs on C6 rat glioma cells. Expression of proteins involved in control of the cell cycle, apoptosis, angiogenesis, invasion and migration was analyzed using RT-PCR and Western Blotting methods after treatment in vitro and in vivo. Alterations in cyclin D1, E2F-1, pRb, p27, p21, p16, p65, c-myc, ERK1/2, nm23 e b, MMP-2, GPI and Secreted Brevican, Tenascin-R, Tenascin-C, VEGF-A, Flt1, Flk1, Bax, PPARg, p53, COX-2, EP1, 2, 3 and 4, Ku70 and 80 expression were observed. In conclusion, GLA and Ruthenium-Ibuprofen complex has multiple target wich translate into the inhibition of proliferation.
Cartier, Jessy. "Influence de clAP1 sur la prolifération cellulaire." Thesis, Dijon, 2010. http://www.theses.fr/2010DIJOS016.
The inhibitor of apoptosis protein cIAP1 (cellular inhibitor of apoptosis protein-1) from the IAP family (Inhibitor of Apoptosis Protein) is an E3 ubiquitin ligase that displays oncogenic properties. Our team is interested in the mecanisms that allow macrophagic differentiation from monocytes. cIAP1 is relocalised from the nucleus to the cytoplasm during the differentiation of many kind of cellular models (macrophages, dendritic cells, colon epithelial cells, hematopoietic stem cells, cardiomyocytes). The well-known functions of cIAP1 are associated with its cytoplasmic localisation, where it regulates the TNFα receptors and NF-κB signalling pathways. During macrophage differentiation, we show that cIAP1, once it is in cytoplasm, induces TRAF-2 degradation, a molecular adaptator of the TNFα receptors family and NF-κB signalling pathways. This degradation blocks the canonical pathway of NF-κB and is essential for the terminal differentiation into macrophages that needs a transitory activation of this pathway. However, cIAP1 is mainly expressed in the nucleus on many cell types which is not in accordance with its cell signalling activity. My objective was to investigate the nuclear function of cIAP1 in proliferative cells or during macrophage differentiation. My work identifies a function of cIAP1 in proliferation regulation. cIAP1 interacts with E2F1 transcription factor and favors its recruitment on Cyclins E and A promoters, both involved in G1/S and G2 phases of the cell cycle, which leads to high level of transcript and protein expression of these two targets. It seems that cIAP1 regulates the cellular proliferation and is important for the balance between proliferation and differentiation, two mechanisms tightly connected in cells
Souberan, Aurélie. "Les inhibiteurs de l'apoptose, une nouvelle cible thérapeutique dans les glioblastomes." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0648/document.
Glioblastomas (GBs) are the most aggressive primary brain tumors in adults. The causes of therapeutic failure are unknown and are multiples, such as tumor cell resistance to apoptosis, the presence of cancer stem cells or a pro-tumor microenvironment. Thus, the discovery of therapeutic molecules with pleiotropic action is particularly interesting. In this context, we are interested in smac mimetics (SM), antagonists of inhibitor of apoptosis proteins (IAPs) and most often antagonize cIAP1, cIAP2, XIAP and ML-IAP.We investigated whether IAPs could be attractive therapeutic targets in human GBs by studying their expression and their possible prognostic values. All IAPs were expressed in various degrees in GBs and ML-IAP was associated with a worse prognosis. Therefore, we chose GDC-0152 for the rest of our experiments because it antagonizes the different IAPs and in particular ML-IAP. We showed that GDC-0152 induces apoptosis in vitro, increases the survival of GB-bearing mice and slows tumor growth in vivo.We investigated whether the effect of GDC-0152 could be different depending on the oxygen level. Indeed, GBs are part of the most hypoxic tumors. For this purpose, four GB stem cell lines were grown in normoxia and hypoxia. We found that GDC-0152 has an anti-tumor effect regardless of oxygen level, but the signaling pathways involved were different. In normoxia, GDC-0152 induces differentiation of GB stem cells (NF-κB pathway) and in hypoxia it induces apoptosis and decreases cell proliferation (ATR pathway).This work highlights the importance of the preclinical model used in the characterization of a new molecule effects and the therapeutic potential of SM in GBs