Mansuelle P

References (8)

Title : The Ig-like domain of Punctin\/MADD-4 is the primary determinant for interaction with the ectodomain of neuroligin NLG-1 - Platsaki_2020_J.Biol.Chem_295_16267
Author(s) : Platsaki S , Zhou X , Pinan-Lucarre B , Delauzun V , Tu H , Mansuelle P , Fourquet P , Bourne Y , Bessereau JL , Marchot P
Ref : Journal of Biological Chemistry , 295 :16267 , 2020
Abstract : Punctin/MADD-4, a member of the ADAMTSL extracellular matrix protein family, was identified as an anterograde synaptic organizer in the nematode Caenorhabditis elegans. At GABAergic neuromuscular junctions, the short isoform MADD-4B binds the ectodomain of neuroligin NLG-1, itself a postsynaptic organizer of inhibitory synapses. To identify the molecular bases of their partnership, we generated recombinant forms of the two proteins and carried out a comprehensive biochemical and biophysical study of their interaction, complemented by an in vivo localization study. We show that spontaneous proteolysis of MADD-4B first generates a shorter N-MADD-4B form, which comprises four thrombospondin (TSP) domains and one Ig-like domain and binds NLG-1. A second processing event eliminates the C-terminal Ig-like domain along with the ability of N-MADD-4B to bind NLG-1. These data identify the Ig-like domain as the primary determinant for N-MADD-4B interaction with NLG-1 in vitro We further demonstrate in vivo that this Ig-like domain is essential, albeit not sufficient per se, for efficient recruitment of GABA(A) receptors at GABAergic synapses in C. elegans The interaction of N-MADD-4B with NLG-1 is also disrupted by heparin, used as a surrogate for the extracellular matrix component, heparan sulfate. High-affinity binding of heparin/heparan sulfate to the Ig-like domain may proceed from surface charge complementarity, as suggested by homology three-dimensional modeling. These data point to N-MADD-4B processing and cell-surface proteoglycan binding as two possible mechanisms to regulate the interaction between MADD-4B and NLG-1 at GABAergic synapses.
ESTHER : Platsaki_2020_J.Biol.Chem_295_16267
PubMedSearch : Platsaki_2020_J.Biol.Chem_295_16267
PubMedID: 32928959

Title : Characterization of all the lipolytic activities in pancreatin and comparison with porcine and human pancreatic juices - Salhi_2020_Biochimie_169_106
Author(s) : Salhi A , Amara S , Mansuelle P , Puppo R , Lebrun R , Gontero B , Aloulou A , Carriere F
Ref : Biochimie , 169 :106 , 2020
Abstract : Porcine pancreatic extracts (PPE), also named pancreatin, are commonly used as a global source of pancreatic enzymes for enzyme replacement therapy in patients with exocrine pancreatic insufficiency. They are considered as a good substitute of human pancreatic enzymes and they have become a material of choice for in vitro models of digestion. Nevertheless, while the global PPE contents in lipase, protease and amylase activities are well characterized, little is known about individual enzymes. Here we characterized the lipase, phospholipase, cholesterol esterase and galactolipase activities of PPE and compared them with those of porcine (PPJ) and human (HPJ) pancreatic juices. The phospholipase to lipase activity ratio was similar in PPJ and HPJ, but was 4-fold lower in PPE. The galactolipase and cholesterol esterase activities were found at lower levels in PPJ compared to HPJ, and they were further reduced in PPE. The enzymes known to display these activities in HPJ, pancreatic lipase-related protein 2 (PLRP2) and carboxylester hydrolase/bile salt-stimulated lipase (CEH/BSSL), were identified in PPJ using gel filtration experiments, SDS-PAGE and LC-MS/MS analysis. The galactolipase and cholesterol esterase activities of PPE indicated that PLRP2 and CEH/BSSL are still present at low levels in this enzyme preparation, but they were not detected by mass spectrometry. Besides differences between porcine and human enzymes, the lower levels of phospholipase, galactolipase and cholesterol esterase activities in PPE are probably due to some proteolysis occurring during the production process. In conclusion, PPE do not provide a full substitution of the lipolytic enzymes present in HPJ.
ESTHER : Salhi_2020_Biochimie_169_106
PubMedSearch : Salhi_2020_Biochimie_169_106
PubMedID: 31288050

Title : Identification of a new natural gastric lipase inhibitor from star anise - Kamoun_2019_Food.Funct_10_469
Author(s) : Kamoun J , Rahier R , Sellami M , Koubaa I , Mansuelle P , Lebrun R , Berlioz-Barbier A , Fiore M , Alvarez K , Abousalham A , Carriere F , Aloulou A
Ref : Food Funct , 10 :469 , 2019
Abstract : The identification and isolation of bioactive compounds are of great interest in the drug delivery field, despite being a difficult task. We describe here an innovative strategy for the identification of a new gastric lipase inhibitor from star anise for the treatment of obesity. After plant screening assays for gastric lipase inhibition, star anise was selected and investigated by bioactivity guided fractionation. MALDI-TOF mass spectrometry and peptide mass fingerprinting allowed the detection of an inhibitor covalently bound to the catalytic serine of gastric lipase. A mass-directed screening approach using UPLC-HRMS and accurate mass determination searching identified the flavonoid myricitrin-5-methyl ether (M5ME) as a lipase inhibitor. The inhibitory activity was rationalized based on molecular docking, showing that M5ME is susceptible to nucleophilic attack by gastric lipase. Overall, our data suggest that M5ME may be considered as a potential candidate for future application as a gastric lipase inhibitor for the treatment of obesity.
ESTHER : Kamoun_2019_Food.Funct_10_469
PubMedSearch : Kamoun_2019_Food.Funct_10_469
PubMedID: 30632597
Gene_locus related to this paper: human-LIPF

Title : Biochemical characterization of Yarrowia lipolytica LIP8, a secreted lipase with a cleavable C-terminal region - Kamoun_2015_Biochim.Biophys.Acta_1851_129
Author(s) : Kamoun J , Schue M , Messaoud W , Baignol J , Point V , Mateos-Diaz E , Mansuelle P , Gargouri Y , Parsiegla G , Cavalier JF , Carriere F , Aloulou A
Ref : Biochimica & Biophysica Acta , 1851 :129 , 2015
Abstract : Yarrowia lipolytica is a lipolytic yeast possessing 16 paralog genes coding for lipases. Little information on these lipases has been obtained and only the major secreted lipase, namely YLLIP2, had been biochemically and structurally characterized. Another secreted lipase, YLLIP8, was isolated from Y. lipolytica culture medium and compared with the recombinant enzyme produced in Pichia pastoris. N-terminal sequencing showed that YLLIP8 is produced in its active form after the cleavage of a signal peptide. Mass spectrometry analysis revealed that YLLIP8 recovered from culture medium lacks a C-terminal part of 33 amino acids which are present in the coding sequence. A 3D model of YLLIP8 built from the X-ray structure of the homologous YLLIP2 lipase shows that these truncated amino acids in YLLIP8 belong to an additional C-terminal region predicted to be mainly helical. Western blot analysis shows that YLLIP8 C-tail is rapidly cleaved upon enzyme secretion since both cell-bound and culture supernatant lipases lack this extension. Mature recombinant YLLIP8 displays a true lipase activity on short-, medium- and long-chain triacylglycerols (TAG), with an optimum activity at alkaline pH on medium chain TAG. It has no apparent regioselectivity in TAG hydrolysis, thus generating glycerol and FFAs as final lipolysis products. YLLIP8 properties are distinct from those of the 1,3-regioselective YLLIP2, acting optimally at acidic pH. These lipases are tailored for complementary roles in fatty acid uptake by Y. lipolytica.
ESTHER : Kamoun_2015_Biochim.Biophys.Acta_1851_129
PubMedSearch : Kamoun_2015_Biochim.Biophys.Acta_1851_129
PubMedID: 25449652
Gene_locus related to this paper: yarli-LIP8

Title : Phoneutria nigriventer toxin 1: a novel, state-dependent inhibitor of neuronal sodium channels that interacts with micro conotoxin binding sites - Martin-Moutot_2006_Mol.Pharmacol_69_1931
Author(s) : Martin-Moutot N , Mansuelle P , Alcaraz G , Dos Santos RG , Cordeiro MN , De Lima ME , Seagar M , Van Renterghem C
Ref : Molecular Pharmacology , 69 :1931 , 2006
Abstract : A toxin was purified to homogeneity from the venom of the South American armed spider Phoneutria nigriventer and found to have a molecular mass of 8600 Da and a C-terminally amidated glycine residue. It appears to be identical to Toxin 1 (Tx1) isolated previously from this venom. Tx1 reversibly inhibited sodium currents in Chinese hamster ovary cells expressing recombinant sodium (Na(v)1.2) channels without affecting their fast biophysical properties. The kinetics of inhibition of peak sodium current varied with membrane potential, with on-rates increasing and off-rates decreasing with more depolarized holding potentials in the -100 to -50 mV range. Thus, the apparent affinity of Tx1 for the channel increases as the membrane is depolarized. A mono[(125)I]iodo-Tx1 derivative displayed high-affinity binding to a single class of sites (K(D) = 80 pM, B(max) = 0.43 pmol/mg protein) in rat brain membranes. Solubilized binding sites were immunoprecipitated by antibodies directed against a conserved motif in sodium channel alpha subunits. (125)I-Tx1 binding was competitively displaced by mu conotoxin GIIIB (IC(50) = 0.5 microM) but not by 1 microM tetrodotoxin. However, the inhibition of (125)I-Tx1 binding by mu conotoxin GIIIB was abrogated in the presence of tetrodotoxin (1 microM). Patch-clamp and binding data indicate that P. nigriventer Tx1 is a novel, state-dependent sodium-channel blocker that binds to a site in proximity to pharmacological site 1, overlapping mu conotoxin but not tetrodotoxin binding sites.
ESTHER : Martin-Moutot_2006_Mol.Pharmacol_69_1931
PubMedSearch : Martin-Moutot_2006_Mol.Pharmacol_69_1931
PubMedID: 16505156

Title : Phoneutria nigriventer omega-phonetoxin IIA blocks the Cav2 family of calcium channels and interacts with omega-conotoxin-binding sites - Dos_2002_J.Biol.Chem_277_13856
Author(s) : Dos Santos RG , Van Renterghem C , Martin-Moutot N , Mansuelle P , Cordeiro MN , Diniz CR , Mori Y , De Lima ME , Seagar M
Ref : Journal of Biological Chemistry , 277 :13856 , 2002
Abstract : omega-Phonetoxin IIA (omegaPtxIIA), a peptide from spider venom (Phoneutria nigriventer), inhibits high threshold voltage-dependent calcium currents in neurons. To define its pharmacological specificity, we have used patch-clamp methods in cell lines expressing recombinant Ca(v)2.1, Ca(v)2.2, and Ca(v)2.3 channels (P/Q-, N-, and R-type currents, respectively). Calcium currents generated by Ca(v)2.1 and Ca(v)2.2 were blocked almost irreversibly by 3 nm omegaPtxIIA, whereas Ca(v)2.3 showed partial and readily reversible inhibition. Binding assays with mono[(125)I]iodo-omegaPtxIIA indicated that membranes expressing recombinant Ca(v)2.1 or Ca(v)2.2 channels showed a single class of sites with similar affinity (K(D) approximately 50 pm), whereas low affinity interactions were detectable with Ca(v)2.3. Kinetic, saturation, and displacement assays demonstrated that rat brain synaptosomes displayed multiple classes of binding sites for (125)I-omegaPtxIIA. High affinity binding of (125)I-omegaPtxIIA was totally displaced by omegaPtxIIA (K(i) = 100 pm), but only partially by omega-conotoxin GVIA (25% inhibition) and omega-conotoxin MVIIC (50% inhibition at 0.3 microm). (125)I-omegaPtxIIA thus defines a unique high affinity binding site that is predominantly associated with Ca(v)2.1 or Ca(v)2.2 channels.
ESTHER : Dos_2002_J.Biol.Chem_277_13856
PubMedSearch : Dos_2002_J.Biol.Chem_277_13856
PubMedID: 11827974

Title : A new scorpion venom toxin paralytic to insects that affects Na+ channel activation. Purification, structure, antigenicity and mode of action - Borchani_1996_Eur.J.Biochem_241_525
Author(s) : Borchani L , Mansuelle P , Stankiewicz M , Grolleau F , Cestele S , Karoui H , Lapied B , Rochat H , Pelhate M , el Ayeb M
Ref : European Journal of Biochemistry , 241 :525 , 1996
Abstract : A new toxin, BotIT2, with a unique mode of action on the isolated giant axon of the cockroach Periplaneta americana and DUM (dorsal unpaired median) neurons, has been purified from the venom of the scorpion Buthus occitanus tunetanus. Its structural, antigenic and pharmacological properties are compared to those of three other groups of neurotoxins found in Buthidae scorpion venoms. Like excitatory, depressant and alpha-type insect-selective neurotoxins, BotIT2 is toxic to insects, but shows the following common and distinctive characteristics. (a) As alpha-type toxins, BotIT2 lack strict selectivity to insects; they have measurable but low toxicity to mice. (b) As depressant toxins and unlike alpha-type toxins, BotIT2 is able to displace iodinated AaHIT from its binding sites in insect neuronal membranes. This indicates that the binding site for BotIT2 is identical, contiguous or in allosteric interaction with that of AaHIT and depressant toxins. (c) The BotIT2 amino acid sequence shows strong similarity to depressant toxins. However, unexpectedly, despite this high sequence similarity, BotIT2 shares moderate cross-antigenic reactivity with depressant toxins. (d) Voltage and current-clamp studies show that BotIT2 induces limited depolarization concomitantly with the development of depolarizing after potential, repetitive activity and later plateau potentials terminated by bursts. Under voltage-clamp conditions, BotIT2 specifically acts on Na+ channels by decreasing the peak Na+ current and by simultaneously inducing a new current with very slow activation/deactivation kinetics. The voltage dependence of this slow current is not significantly different from that of the control current. These observations indicate that BotIT2 chiefly modifies the kinetics of axonal and DUM neuronal membrane Na(+)-channel activation.
ESTHER : Borchani_1996_Eur.J.Biochem_241_525
PubMedSearch : Borchani_1996_Eur.J.Biochem_241_525
PubMedID: 8917451

Title : Binding of 125I-fasciculin to rat brain acetylcholinesterase. The complex still binds diisopropyl fluorophosphate - Marchot_1993_J.Biol.Chem_268_12458
Author(s) : Marchot P , Khelif A , Ji YH , Mansuelle P , Bougis PE
Ref : Journal of Biological Chemistry , 268 :12458 , 1993
Abstract : Iodination of fasciculin 3 (FAS3) from Dendroaspis viridis venom provided us with a fully active specific probe of fasciculin binding sites on rat brain acetylcholinesterase (AChE). Binding and inhibition are concomitant, as association and inhibition rate constants k1 and ki are identical. The 125I-FAS3.AChE complex dissociates very slowly (t 1/2 = 48 h) and is characterized by a dissociation constant, Kd, of 0.4 pM. All the specific binding of 125I-FAS3 to AChE is prevented by FAS3 as from D. angusticeps venom (Kd = 0.4, 14, and 25 pM, respectively). It is also prevented by propidium iodide, BW284C51, and d-tubocurarine, which bind to peripheral anionic sites of AChE, by Ca2+ and Mg2+, known to enhance AChE activity through an allosteric phenomenon and by acetylthiocholine concentrations which lead to excess substrate inhibition of the enzyme. Diisopropyl fluorphosphate and paroxon, which inhibit AChE by phosphorylating the catalytic serine, have no effect on either the binding rate or the number of binding sites of 125I-FAS3. O-Ethyl-S2-diisopropylaminoethyl methylphosphonothionate, however, which binds irreversibly to the AChE catalytic site but reversibly to a peripheral site, induces a 130% increase in the binding rate of 125I-FAS3, without changing the total number of 125I-FAS3 binding sites. Our results demonstrate that fasciculins bind on a peripheral site of AChE, distinct from the catalytic site and, at least partly, common with the sites on which some cationic inhibitors and the substrate in excess bind. Since phosphorylation of the catalytic serine (esteratic subsite) by [1,3-3H]diisopropyl fluorophosphate can still occur on the FAS3.AChE complex, the structural modification induced by fasciculins may affect the anionic subsite of AChE catalytic site.
ESTHER : Marchot_1993_J.Biol.Chem_268_12458
PubMedSearch : Marchot_1993_J.Biol.Chem_268_12458
PubMedID: 8509385