Ehret-Sabatier L

References (13)

Title : Design and activity of cationic fullerene derivatives as inhibitors of acetylcholinesterase - Pastorin_2006_Org.Biomol.Chem_4_2556
Author(s) : Pastorin G , Marchesan S , Hoebeke J , Da Ros T , Ehret-Sabatier L , Briand JP , Prato M , Bianco A
Ref : Org Biomol Chem , 4 :2556 , 2006
Abstract : Four different regioisomers of cationic bis-N,N-dimethylfulleropyrrolidinium salts have been prepared and evaluated as inhibitors of the enzymatic activity of acetylcholinesterase. These fullerene-based derivatives were found to be noncompetitive inhibitors of acetylthiocholine hydrolysis. Molecular modelling was used to describe the possible interactions between the fullerene cage and the amino acids surrounding the cavity of the enzyme. The cationic C(60) derivatives used in this study represent a new class of molecules potentially able to modulate the enzymatic activity of acetylcholinesterase.
ESTHER : Pastorin_2006_Org.Biomol.Chem_4_2556
PubMedSearch : Pastorin_2006_Org.Biomol.Chem_4_2556
PubMedID: 16791318

Title : Photoaffinity labeling with [3H]DDF support the existence of two quaternary ammonium binding domains in human butyrylcholinesterase -
Author(s) : Nachon F , Ehret-Sabatier L , Goeldner M
Ref : Journal de Physiologie (Paris) , 92 :473 , 1998
PubMedID:

Title : Site-Directed Photo-Probes for Structural and Functional Investigations on Cholinesterases -
Author(s) : Nachon F , Colas C , Peng L , Ehret-Sabatier L , Goeldner M
Ref : In: Structure and Function of Cholinesterases and Related Proteins - Proceedings of Sixth International Meeting on Cholinesterases , (Doctor, B.P., Taylor, P., Quinn, D.M., Rotundo, R.L., Gentry, M.K. Eds) Plenum Publishing Corp. :379 , 1998
PubMedID:

Title : Photoaffinity Labeling with [3H]-DDF Reveals TRP82 and TYR332 are Involved in Two Quaternary Ammonium Binding Domains of Human Butyrylcholinesterase -
Author(s) : Nachon F , Ehret-Sabatier L , Goeldner M
Ref : In: Structure and Function of Cholinesterases and Related Proteins - Proceedings of Sixth International Meeting on Cholinesterases , (Doctor, B.P., Taylor, P., Quinn, D.M., Rotundo, R.L., Gentry, M.K. Eds) Plenum Publishing Corp. :236 , 1998
PubMedID:

Title : Trp82 and Tyr332 are involved in two quaternary ammonium binding domains of human butyrylcholinesterase as revealed by photoaffinity labeling with [3H]DDF - Nachon_1998_Biochemistry_37_10507
Author(s) : Nachon F , Ehret-Sabatier L , Loew D , Colas C , Van Dorsselaer A , Goeldner M
Ref : Biochemistry , 37 :10507 , 1998
Abstract : Purified butyrylcholinesterase (BCHE) was photolabeled by [3H]-p-N, N-dimethylamino benzene diazonium ([3H]DDF) to identify the quaternary ammonium binding sites on this protein [Ehret-Sabatier, L. , Schalk, I., Goeldner, M., and Hirth, C. (1992) Eur. J. Biochem. 203, 475-481]. The covalent photoincorporation occurs with a stoichiometry of one mole of probe per mole of inactivated site and could be fully prevented by several cholinergic inhibitors such as tacrine or tetramethylammonium. After complete deglycosylation of the enzyme using N-glycosidase F, the alkylated protein was trypsinolyzed and the digests were analyzed by HPLC coupled to ES-MS. A direct comparison of tryptic fragments from labeled and unlabeled BCHE allowed us to identify the tryptic peptide Tyr61-Lys103 as carrying the probe. Purification of the labeled peptides by anion-exchange chromatography gave a major radioactive peak which was further fractionated by reversed-phase HPLC leading to three, well-resolved, radioactive peaks. Microsequencing revealed that two of these peaks contained an overlapping sequence starting at Tyr61, while the third peak contained a sequence extending from Thr315. Radioactive signals could be unambiguously attributed to positions corresponding to residues Trp82 and Tyr332. This labeling study establishes the existence of two different binding domains for quaternary ammonium in BCHE and exemplifies additional cation/pi interactions in cholinergic proteins. This work strongly supports the existence of a peripheral anionic site in BCHE, implying residue Tyr332 as a key element.
ESTHER : Nachon_1998_Biochemistry_37_10507
PubMedSearch : Nachon_1998_Biochemistry_37_10507
PubMedID: 9671522

Title : Irreversible Site-Directed Labeling Studies on Cholinesterases -
Author(s) : Ehret-Sabatier L , Schalk I , Loeb C , Nachon F , Goeldner M
Ref : In Enzyme of the Cholinesterase Family - Proceedings of Fifth International Meeting on Cholinesterases , (Quinn, D.M., Balasubramanian, A.S., Doctor, B.P., Taylor, P., Eds) Plenum Publishing Corp. :163 , 1995
PubMedID:

Title : 6-Coumarin diazonium salt: a specific affinity label of the Torpedo acetylcholinesterase peripheral site - Schalk_1995_Mol.Pharmacol_48_1063
Author(s) : Schalk I , Ehret-Sabatier L , Le Feuvre Y , Bon S , Massoulie J , Goeldner M
Ref : Molecular Pharmacology , 48 :1063 , 1995
Abstract : A 6-coumarin diazonium salt was synthesized and tested on Torpedo acetylcholinesterase as a site-directed irreversible probe for quaternary ammonium binding. The rate of the inactivation was examined as a function of time, inhibitor concentration, and pH, which allowed the determination of the dissociation and the rate constants of this efficient affinity labeling process. Protection experiments using tetramethylammonium, edrophonium, and propidium demonstrated that the labeling reaction occurred exclusively at the peripheral quaternary ammonium binding site of the enzyme. This result was confirmed by the modification of propidium binding at the peripheral site after inactivation reaction, as directly determined by fluorescence. Mutations of the likely labeled amino acid residues, Tyr70 and Tyr121, by histidine and phenylalanine indicated a predominant involvement of Tyr70 over Tyr121 in the coupling reaction.
ESTHER : Schalk_1995_Mol.Pharmacol_48_1063
PubMedSearch : Schalk_1995_Mol.Pharmacol_48_1063
PubMedID: 8848006

Title : Trp279 is involved in the binding of quaternary ammonium at the peripheral site of Torpedo marmorata acetylcholinesterase - Schalk_1994_Eur.J.Biochem_219_155
Author(s) : Schalk I , Ehret-Sabatier L , Bouet F , Goeldner M , Hirth C
Ref : European Journal of Biochemistry , 219 :155 , 1994
Abstract : Specific photoaffinity labelling of purified acetylcholinesterase from Torpedo marmorata by p-N,N-[3H]dimethylamino benzenediazonium and p-N,N-[3H]dibutylamino benzenediazonium derivatives was demonstrated. This occurred at the active site of the enzyme for lower concentrations of the probes and at the peripheral ammonium binding site for higher concentrations. The affinities and the rate constants of alkylation for each probe on both sites have been established. Specific labelling at the peripheral site of the enzyme with both probes allowed the identification of radio-labelled peptides having the common sequence K270PQELIDVEW. The radioactivity was always associated with the residue Trp279 indicating the preferential ammonium complexation with this aromatic residue.
ESTHER : Schalk_1994_Eur.J.Biochem_219_155
PubMedSearch : Schalk_1994_Eur.J.Biochem_219_155
PubMedID: 8306982

Title : Quaternary ligand binding to aromatic residues in the active-site gorge of acetylcholinesterase - Harel_1993_Proc.Natl.Acad.Sci.U.S.A_90_9031
Author(s) : Harel M , Schalk I , Ehret-Sabatier L , Bouet F , Goeldner M , Hirth C , Axelsen PH , Silman I , Sussman JL
Ref : Proceedings of the National Academy of Sciences of the United States of America , 90 :9031 , 1993
Abstract : Binding sites of Torpedo acetylcholinesterase (EC 3.1.1.7) for quaternary ligands were investigated by x-ray crystallography and photoaffinity labeling. Crystal structures of complexes with ligands were determined at 2.8-A resolution. In a complex with edrophonium, and quaternary nitrogen of the ligand interacts with the indole of Trp-84, and its m-hydroxyl displays bifurcated hydrogen bonding to two members of the catalytic triad, Ser-200 and His-440. In a complex with tacrine, the acridine is stacked against the indole of Trp-84. The bisquaternary ligand decamethonium is oriented along the narrow gorge leading to the active site; one quaternary group is apposed to the indole of Trp-84 and the other to that of Trp-279, near the top of the gorge. The only major conformational difference between the three complexes is in the orientation of the phenyl ring of Phe-330. In the decamethonium complex it lies parallel to the surface of the gorge; in the other two complexes it is positioned to make contact with the bound ligand. This close interaction was confirmed by photoaffinity labelling by the photosensitive probe 3H-labeled p-(N,N-dimethylamino)benzenediazonium fluoroborate, which labeled, predominantly, Phe-330 within the active site. Labeling of Trp-279 was also observed. One mole of label is incorporated per mole of AcChoEase inactivated, indicating that labeling of Trp-279 and that of Phe-330 are mutually exclusive. The structural and chemical data, together, show the important role of aromatic groups as binding sites for quaternary ligands, and they provide complementary evidence assigning Trp-84 and Phe-330 to the "anionic" subsite of the active site and Trp-279 to the "peripheral" anionic site.
ESTHER : Harel_1993_Proc.Natl.Acad.Sci.U.S.A_90_9031
PubMedSearch : Harel_1993_Proc.Natl.Acad.Sci.U.S.A_90_9031
PubMedID: 8415649
Gene_locus related to this paper: torca-ACHE

Title : Photoaffinity labelling of cholinesterases. Discrimination between active and peripheral sites [published erratum appears in Eur J Biochem 1992 Jun 15\;206(3):995] - Ehret-Sabatier_1992_Eur.J.Biochem_203_475
Author(s) : Ehret-Sabatier L , Schalk I , Goeldner M , Hirth C
Ref : European Journal of Biochemistry , 203 :475 , 1992
Abstract : Two para-dialkylaminobenzenediazonium salts, the dimethylamino (A) and dibutylamino (B) derivatives, are presented as structural probes for acetylcholinesterase and butyrylcholinesterase. While being reversible competitive inhibitors in the dark, A and B behave, upon irradiation and through the formation of arylcation species, as irreversible labels of ammonium-binding sites of both enzymes. The observed variations of the different inactivation rate constants point to a different structural environment for acetylcholinesterase-binding and butyrylcholinesterase-binding sites. Moreover, in the case of acetylcholinesterase, protection experiments with specific ligands (edrophonium and propidium) showed that the dimethylamino salt A exclusively labels the hydrolytic anionic site, whereas the dibutylamino salt B also labels the peripheral site. Specificities and stoechiometries of the incorporations were determined and, in the case of acetylcholinesterase, the irradiated protein was submitted to chemical degradation. Peptide maps were obtained by gel-permeation chromatography and HPLC, giving access to labelled peptides which belong either to the active or to the peripheral site.
ESTHER : Ehret-Sabatier_1992_Eur.J.Biochem_203_475
PubMedSearch : Ehret-Sabatier_1992_Eur.J.Biochem_203_475
PubMedID: 1735432

Title : Structural Analysis of Acetylcholinesterase Ammonium Binding Sites -
Author(s) : Schalk I , Ehret-Sabatier L
Ref : In Multidisciplinary approaches to cholinesterase functions - Proceedings of Fourth International Meeting on Cholinesterases , (Shafferman, A. and Velan, B., Eds) Plenum Press, New York :117 , 1992
PubMedID:

Title : Aryldiazonium Salts as Affinity or Photo affinity Probes for Labelling Cholinesterases: Towards Enzyme and\/or Binding Site Discrimination -
Author(s) : Ehret-Sabatier L , Goeldner M , Hirth C , Rousseau B
Ref : In: Cholinesterases: Structure, Function, Mechanism, Genetics, and Cell Biology , (Massoulie J, Barnard EA, Chatonnet A, Bacou F, Doctor BP, Quinn DM) American Chemical Society, Washington, DC :245 , 1991
PubMedID:

Title : p-Butyroxybenzenediazonium fluoroborate, substrate of acetylcholinesterase and butyrylcholinesterase, discriminates between the two enzymes by a specific affinity labelling - Ehret-Sabatier_1991_Biochim.Biophys.Acta_1076_137
Author(s) : Ehret-Sabatier L , Goeldner M , Hirth C
Ref : Biochimica & Biophysica Acta , 1076 :137 , 1991
Abstract : p-Butyroxybenzenediazonium fluoroborate 1 was shown to be a substrate of both acetylcholinesterase (AcChE) and butyrylcholinesterase (BCHE) with Michaelis constants of 6.10(-5) M and 1.3. 10(-4)M, respectively. Upon incubation in the dark, 1 was able to discriminate between the two enzymes AcChE was efficiently inactivated in a time-dependent manner while BCHE remained unaffected. Kinetic analysis of the inactivation of AcChE (i) by various concentrations of 1 indicated that it behaves as an affinity label, (ii) at three different pH levels suggested that the pKa of the labelled residue was higher than 7 and (iii) in the presence of different selective ligands for either the active site (edrophonium) or the peripheral site (propidium) indicated that 1 alkylated the active site rather than the peripheral one. Differences of reactivity between AcChE and BCHE suggest a different positioning and/or a different chemical environment of the substrate within two active sites.
ESTHER : Ehret-Sabatier_1991_Biochim.Biophys.Acta_1076_137
PubMedSearch : Ehret-Sabatier_1991_Biochim.Biophys.Acta_1076_137
PubMedID: 1986786