6 research outputs found
Ligations chimiques : synthĂšse d'inhibiteurs extracellulaires de la signalisation HGF/SF-MET
Use of peptides as biomolecules have been extensively applied to various therapeutic fields (cancer, diabetes, AIDS). The challenge for chemists consists in development of new reliable and efficient strategies. Our work especially focused on the conception of two innovative non native chemical ligations bringing an additionnal asset to the existing state of the art.The first ligation, i.e. thiocarbamate ligation, affords alkylthiocarbamate peptides with remarkable yields. Regarding the second one, the azaGly ligation allows the straightforward synthesis of azaGlypeptides. On the other hand, this thesis deals with the design of new peptides suitable to inhibit the signaling pathway of the tyrosineâkinase MET receptor and its ligand HGF/SF (Hepatocyte Growth factor/Scattor factor). Indeed interfering with MET signaling appears to be a promising therapeutic approach.The thiocarbamate ligation disclosed previously along with a classical thioether ligation have been employed for the chemical library design of sulfonated peptids in order to inhibit extracellular interactions. Binding activities assessment of the chemical libray toward the MET extracellular domain has been achieved using a microarray technology. Biological activities (MTT tests and kinase activity) have also been investigated.Les peptides constituent une famille de biomolĂ©cules dont lâutilisation dans diffĂ©rents domaines thĂ©rapeutiques (cancer, diabĂšte, sida) sâest fortement dĂ©veloppĂ©e ces derniĂšres annĂ©es. Le dĂ©fi pour les chimistes consiste Ă y accĂ©der grĂące Ă de nouvelles mĂ©thodes fiables et efficaces. La premiĂšre partie de notre travail a dâabord Ă©tĂ© orientĂ©e vers le dĂ©veloppement deux mĂ©thodes de ligations non natives efficaces et complĂ©mentaires de celles existant. La premiĂšre mĂ©thode, appelĂ©e ligation thiocarbamate, permet dâobtenir des peptides alkylthiocarbamate avec de trĂšs bons rendements, alors que la seconde, appelĂ©e ligation azaGly, aboutit Ă la formation dâun azaGlypeptide. La seconde partie de cette thĂšse traite de la conception et synthĂšse de nouveaux peptides susceptibles dâinhiber la signalisation HGF/SF-MET. Le rĂ©cepteur Ă activitĂ© tyrosine kinase MET et son ligand, lâHGF/SF (Hepatocyte Growth Factor/Scattor Factor), sont des cibles de choix pour une thĂ©rapie anti-cancĂ©reuse. La ligation thiocarbamate, prĂ©cĂ©demment dĂ©crite, et la ligation thioĂ©ther plus classique ont Ă©tĂ© utilisĂ©es pour prĂ©parer une chimiothĂšque de peptides sulfonatĂ©s dâinhiber cette signalisation de façon extracellulaire. La capacitĂ© de liaison des composĂ©s de la chimiothĂšque avec le domaine extracellulaire de MET a Ă©tĂ© Ă©valuĂ©e grĂące Ă la technologie biopuces. LâactivitĂ© biologique (tests MTT, dâactivitĂ© kinase) des meilleurs produits a Ă©tĂ© ensuite Ă©valuĂ©e
Chemical Ligation Synthesis of extracellular inhibitors of HGF/SF-MET signalling pathway
Les peptides constituent une famille de biomolĂ©cules dont lâutilisation dans diffĂ©rents domaines thĂ©rapeutiques (cancer, diabĂšte, sida) sâest fortement dĂ©veloppĂ©e ces derniĂšres annĂ©es. Le dĂ©fi pour les chimistes consiste Ă y accĂ©der grĂące Ă de nouvelles mĂ©thodes fiables et efficaces. La premiĂšre partie de notre travail a dâabord Ă©tĂ© orientĂ©e vers le dĂ©veloppement deux mĂ©thodes de ligations non natives efficaces et complĂ©mentaires de celles existant. La premiĂšre mĂ©thode, appelĂ©e ligation thiocarbamate, permet dâobtenir des peptides alkylthiocarbamate avec de trĂšs bons rendements, alors que la seconde, appelĂ©e ligation azaGly, aboutit Ă la formation dâun azaGlypeptide. La seconde partie de cette thĂšse traite de la conception et synthĂšse de nouveaux peptides susceptibles dâinhiber la signalisation HGF/SF-MET. Le rĂ©cepteur Ă activitĂ© tyrosine kinase MET et son ligand, lâHGF/SF (Hepatocyte Growth Factor/Scattor Factor), sont des cibles de choix pour une thĂ©rapie anti-cancĂ©reuse. La ligation thiocarbamate, prĂ©cĂ©demment dĂ©crite, et la ligation thioĂ©ther plus classique ont Ă©tĂ© utilisĂ©es pour prĂ©parer une chimiothĂšque de peptides sulfonatĂ©s dâinhiber cette signalisation de façon extracellulaire. La capacitĂ© de liaison des composĂ©s de la chimiothĂšque avec le domaine extracellulaire de MET a Ă©tĂ© Ă©valuĂ©e grĂące Ă la technologie biopuces. LâactivitĂ© biologique (tests MTT, dâactivitĂ© kinase) des meilleurs produits a Ă©tĂ© ensuite Ă©valuĂ©e.Use of peptides as biomolecules have been extensively applied to various therapeutic fields (cancer, diabetes, AIDS). The challenge for chemists consists in development of new reliable and efficient strategies. Our work especially focused on the conception of two innovative non native chemical ligations bringing an additionnal asset to the existing state of the art.The first ligation, i.e. thiocarbamate ligation, affords alkylthiocarbamate peptides with remarkable yields. Regarding the second one, the azaGly ligation allows the straightforward synthesis of azaGlypeptides. On the other hand, this thesis deals with the design of new peptides suitable to inhibit the signaling pathway of the tyrosineâkinase MET receptor and its ligand HGF/SF (Hepatocyte Growth factor/Scattor factor). Indeed interfering with MET signaling appears to be a promising therapeutic approach.The thiocarbamate ligation disclosed previously along with a classical thioether ligation have been employed for the chemical library design of sulfonated peptids in order to inhibit extracellular interactions. Binding activities assessment of the chemical libray toward the MET extracellular domain has been achieved using a microarray technology. Biological activities (MTT tests and kinase activity) have also been investigated
Antioxydant activity of ÎČ-carboline derivatives in the LDL oxidation model
A series of b-carboline compounds were synthesized, starting from compound GWC22, their antioxidant activity was determined by inhibition of lipid peroxidation. The oxidation of LDL was induced in the presence of CuSO4 or 2,20-azobis(2-amidinopropane) dihydrochloride (AAPH). The protective actions of these compounds against the cytotoxicity were evaluated with lactate dehydrogenase (LDH) activity in bovine aortic endothelial cells (BAECs) and cellular vitality by measuring mitochondrial activity in the presence of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). Most of compounds showed an higher antioxidant activity than GWC22 derivative (R = 1.6 for 5 mM CuSO4). The best antioxidant activities are phenolic and benzyloxy derivatives with ratio R = 1.9 to 2.8 for 1 mM CuSO4. These substances have protective actions and increase significantly the cell viability
Thiocarbamate-Linked PolysulfonateâPeptide Conjugates As Selective Hepatocyte Growth Factor Receptor Binders
The capacity of many proteins to
interact with natural or synthetic
polyanions has been exploited for modulating their biological action.
However, the polydispersity of these macromolecular polyanions as
well as their poor specificity is a severe limitation to their use
as drugs. An emerging trend in this field is the synthesis of homogeneous
and well-defined polyanionâpeptide conjugates, which act as
bivalent ligands, with the peptide part bringing the selectivity of
the scaffold. Alternately, this strategy can be used for improving
the binding of short peptides to polyanion-binding protein targets.
This work describes the design and first synthesis of homogeneous
polysulfonateâpeptide conjugates using thiocarbamate ligation
for binding to the extracellular domain of MET tyrosine kinase receptor
for hepatocyte growth factor