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Renault F, Sergent B, Charpillet V, Gitiaux C, Vazquez MP. Étude électromyographique du muscle temporalis avant une myoplastie d’allongement dans le syndrome de Moebius. ANN CHIR PLAST ESTH 2017; 62:156-162. [DOI: 10.1016/j.anplas.2016.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 04/18/2016] [Indexed: 10/21/2022]
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Pelier-Cady MC, Renault F. Le nerf radial chez l’adulte et chez l’enfant. Rev Neurol (Paris) 2013. [DOI: 10.1016/j.neurol.2013.01.608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Trovaslet-Leroy M, Musilova L, Renault F, Brazzolotto X, Misik J, Novotny L, Froment MT, Gillon E, Loiodice M, Verdier L, Masson P, Rochu D, Jun D, Nachon F. Organophosphate hydrolases as catalytic bioscavengers of organophosphorus nerve agents. Toxicol Lett 2011; 206:14-23. [PMID: 21683774 DOI: 10.1016/j.toxlet.2011.05.1041] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 05/27/2011] [Accepted: 05/31/2011] [Indexed: 01/30/2023]
Abstract
Bioscavengers are molecules able to neutralize neurotoxic organophosphorus compounds (OP) before they can reach their biological target. Human butyrylcholinesterase (hBChE) is a natural bioscavenger each molecule of enzyme neutralizing one molecule of OP. The amount of natural enzyme is insufficient to achieve good protection. Thus, different strategies have been envisioned. The most straightforward consists in injecting a large dose of highly purified natural hBChE to increase the amount of bioscavenger in the bloodstream. This proved to be successful for protection against lethal doses of soman and VX but remains expensive. An improved strategy is to regenerate prophylactic cholinesterases (ChE) by administration of reactivators after exposure. But broad-spectrum efficient reactivators are still lacking, especially for inhibited hBChE. Cholinesterase mutants capable of reactivating spontaneously are another option. The G117H hBChE mutant has been a prototype. We present here the Y124H/Y72D mutant of human acetylcholinesterase; its spontaneous reactivation rate after V-agent inhibition is increased up to 110 fold. Catalytic bioscavengers, enzymes capable of hydrolyzing OP, present the best alternative. Mesophilic bacterial phosphotriesterase (PTE) is a candidate with good catalytic efficiency. Its enantioselectivity has been enhanced against the most potent OP isomers by rational design. We show that PEGylation of this enzyme improves its mean residence time in the rat blood stream 24-fold and its bioavailability 120-fold. Immunogenic issues remain to be solved. Human paraoxonase 1 (hPON1) is another promising candidate. However, its main drawback is that its phosphotriesterase activity is highly dependent on its environment. Recent progress has been made using a mammalian chimera of PON1, but we provide here additional data showing that this chimera is biochemically different from hPON1. Besides, the chimera is expected to suffer from immunogenic issues. Thus, we stress that interest for hPON1 must not fade away, and in particular, the 3D structure of the hPON1 eventually in complex with OP has to be solved.
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Affiliation(s)
- Marie Trovaslet-Leroy
- Département de Toxicologie, Institut de Recherches Biomédicales des Armées, 38700 La Tronche, France
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Bloc S, Mercadal L, Cuny P, Renault F, Dessieux T, Garnier T, Komly B, Leclerc P, Morel B, Dhonneur G, Ecoffey C. Fast-tracking en anesthésie locorégionale périphérique : étude préliminaire de faisabilité. ACTA ACUST UNITED AC 2010; 29:716-9. [DOI: 10.1016/j.annfar.2010.05.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 05/20/2010] [Indexed: 11/24/2022]
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Collombet JM, Elias M, Gotthard G, Four E, Renault F, Joffre A, Baubichon D, Rochu D, Chabrière E. Eukaryotic DING proteins are endogenous: an immunohistological study in mouse tissues. PLoS One 2010; 5:e9099. [PMID: 20161715 PMCID: PMC2817009 DOI: 10.1371/journal.pone.0009099] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Accepted: 01/20/2010] [Indexed: 11/19/2022] Open
Abstract
Background DING proteins encompass an intriguing protein family first characterized by their conserved N-terminal sequences. Some of these proteins seem to have key roles in various human diseases, e.g., rheumatoid arthritis, atherosclerosis, HIV suppression. Although this protein family seems to be ubiquitous in eukaryotes, their genes are consistently lacking from genomic databases. Such a lack has considerably hampered functional studies and has fostered therefore the hypothesis that DING proteins isolated from eukaryotes were in fact prokaryotic contaminants. Principal Findings In the framework of our study, we have performed a comprehensive immunological detection of DING proteins in mice. We demonstrate that DING proteins are present in all tissues tested as isoforms of various molecular weights (MWs). Their intracellular localization is tissue-dependant, being exclusively nuclear in neurons, but cytoplasmic and nuclear in other tissues. We also provide evidence that germ-free mouse plasma contains as much DING protein as wild-type. Significance Hence, data herein provide a valuable basis for future investigations aimed at eukaryotic DING proteins, revealing that these proteins seem ubiquitous in mouse tissue. Our results strongly suggest that mouse DING proteins are endogenous. Moreover, the determination in this study of the precise cellular localization of DING proteins constitute a precious evidence to understand their molecular involvements in their related human diseases.
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Affiliation(s)
- Jean-Marc Collombet
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, Centre de Recherche du Service de Santé des Armées, La Tronche, France
| | - Mikael Elias
- Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique-Aix Marseille Université, Marseille, France
| | - Guillaume Gotthard
- Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique-Aix Marseille Université, Marseille, France
| | - Elise Four
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, Centre de Recherche du Service de Santé des Armées, La Tronche, France
| | - Frédérique Renault
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, Centre de Recherche du Service de Santé des Armées, La Tronche, France
| | - Aurélie Joffre
- Service de Microscopie et d'Imagerie Médicale, Institut de Recherche Biomédicale des Armées, Centre de Recherche du Service de Santé des Armées, La Tronche, France
| | - Dominique Baubichon
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, Centre de Recherche du Service de Santé des Armées, La Tronche, France
| | - Daniel Rochu
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, Centre de Recherche du Service de Santé des Armées, La Tronche, France
| | - Eric Chabrière
- Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique-Aix Marseille Université, Marseille, France
- * E-mail:
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Abstract
AIM Hydroxychloroquine therapy during pregnancy is thought to be safe for foetuses. Normal visual function has been showed on clinical grounds in infants exposed in utero to hydroxychloroquine, but there are few visual neurophysiological data. Our study was designed to assess retina and visual pathways using electroretinogram and visual evoked potentials in a series of infants born to mothers treated by hydroxychloroquine for connective tissue diseases. METHODS Twenty-one infants (3-7 months of age) were consecutively examined between June 2002 and May 2007. Full-field electroretinogram was recorded by contact lens electrodes and visual evoked potentials were recorded by occipital surface electrodes using flash stimulation in mesopic condition. Analysis was focused on the amplitudes and latencies of the a- and b-waves of electroretinogram and the latency of the P(100) component of visual evoked potentials. RESULTS Electroretinogram abnormalities were detected in six infants, associated with delayed visual evoked potentials in four of them. CONCLUSION Early electroretinogram and visual evoked potentials testing evidenced neurophysiological visual disturbances in a subset of infants born to mothers treated by hydroxychloroquine. Systematic clinical and neurophysiological vision testing during childhood is needed to detect possible consequences of antenatal exposure to hydroxychloroquine.
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Affiliation(s)
- F Renault
- Unité de neurophysiologie clinique, Hôpital Armand-Trousseau, Assistance Publique-Hôpitaux de Paris, Paris, France.
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Diemer H, Elias M, Renault F, Rochu D, Contreras-Martel C, Schaeffer C, Van Dorsselaer A, Chabriere E. Tandem use of X-ray crystallography and mass spectrometry to obtain ab initio the complete and exact amino acids sequence of HPBP, a human 38-kDa apolipoprotein. Proteins 2007; 71:1708-20. [DOI: 10.1002/prot.21866] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Quijano-Roy S, Allamand V, Riahi N, Gartioux C, Briñas L, Leclair-Richard D, Zeller R, Ledeuil C, Commare M, Viollet L, Bönnemann C, Mayer M, Chaigne D, Essid N, Renault F, Barois A, Ferreiro A, Romero N, Richard P, Guicheney P, Estournet B. C.P.2.03 Predictive factors of severity and management of respiratory and orthopaedic complications in 16 Ullrich CMD patients. Neuromuscul Disord 2007. [DOI: 10.1016/j.nmd.2007.06.279] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Chabriere E, Elias M, Diemer H, Renault F, Contreras-Martel C, Van Dorsselaer A. Tandem use of crystallography and mass spectrometry to sequence ab initioHPBP. Acta Crystallogr A 2007. [DOI: 10.1107/s0108767307099503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Rochu D, Renault F, Cléry-Barraud C, Chabrière E, Masson P. Stability of highly purified human paraoxonase (PON1): Association with human phosphate binding protein (HPBP) is essential for preserving its active conformation(s). Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 2007; 1774:874-83. [PMID: 17556053 DOI: 10.1016/j.bbapap.2007.05.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 03/30/2007] [Accepted: 05/02/2007] [Indexed: 11/24/2022]
Abstract
The biological role of human paraoxonase (PON1) remains unclear, whilst there is a consensus that the enzyme has a protective influence. A toxicological role, protecting from environmental poisoning by organophosphate derivatives drove earlier works, and more recently, clinical interest has focused on a protective role in vascular disease. PON1 resides essentially on HDL particles, a complex and dynamic molecular environment. Our recent discovery of the human phosphate binding protein (HPBP), displaying a firm propensity to associate with PON1, has steered new directions for characterizing PON1 functional state. Here, we report investigations on the effect of HPBP on oligomerization, storage and thermal stability of PON1. We found that purified PON1 is as a mixture of at least two states, and that the absence of HPBP favors homo-oligomerization of PON1 into state(s) of higher molecular size. We showed that HPBP allows stabilizing active conformation(s) of PON1 disencumbered of its natural environment. We also showed that PON1 exhibits intrinsically a remarkable thermal stability, and that the association of HPBP strongly contributes to slow the denaturation rate. A hybrid recombinant PON1 was shown more thermostable than the human enzyme, and its stability was unaffected by the presence of HPBP. Altogether, the results strongly encourage further study of the human enzyme.
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Affiliation(s)
- Daniel Rochu
- Département de Toxicologie, Centre de Recherches du Service de Santé des Armées, BP 87, 38702 La Tronche cedex, France.
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Arsene I, Bearden IG, Beavis D, Bekele S, Besliu C, Budick B, Bøggild H, Chasman C, Christensen CH, Dalsgaard HH, Debbe R, Gaardhøje JJ, Hagel K, Ito H, Jipa A, Johnson EB, Jørgensen CE, Karabowicz R, Katrynska N, Kim EJ, Larsen TM, Lee JH, Lindal S, Løvhøiden G, Majka Z, Murray M, Natowitz J, Nielsen BS, Nygaard C, Płaneta R, Rami F, Renault F, Ristea C, Ristea O, Röhrich D, Samset BH, Sanders SJ, Scheetz RA, Staszel P, Tveter TS, Videbaek F, Wada R, Yin Z, Yang H, Zgura IS. Production of mesons and baryons at high rapidity and high p(T) in proton-proton collisions at square root[s] = 200 GeV. Phys Rev Lett 2007; 98:252001. [PMID: 17678015 DOI: 10.1103/physrevlett.98.252001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Indexed: 05/16/2023]
Abstract
We present particle spectra for charged hadrons pi(+/-), K(+/-), p, and p[over] from pp collisions at square root[s] = 200 GeV measured for the first time at forward rapidities (2.95 and 3.3). The kinematics of these measurements are skewed in a way that probes the small momentum fraction in one of the protons and large fractions in the other. Large proton to pion ratios are observed at values of transverse momentum that extend up to 4 GeV/c, where protons have momenta up to 35 GeV. Next-to-leading order perturbative QCD calculations describe the production of pions and kaons well at these rapidities, but fail to account for the large proton yields and small p[over]/p ratios.
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Affiliation(s)
- I Arsene
- Department of Physics, University of Oslo, Oslo, Norway
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Jun D, Kuca K, Bajgar J, Hruby M, Kucka J, Renault F, Masson P. Phosphotriesterase modified by poly[N-(2-hydroxypropyl)methacrylamide]. Toxicology 2007. [DOI: 10.1016/j.tox.2006.04.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Rochu D, Renault F, Elias M, Hanne S, Cléry-Barraud C, Chabrière E, Masson P. Functional states, storage and thermal stability of human paraoxonase: Drawbacks, advantages and potential. Toxicology 2007. [DOI: 10.1016/j.tox.2006.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Morales R, Berna A, Carpentier P, Contreras-Martel C, Renault F, Nicodeme M, Chesne-Seck ML, Bernier F, Dupuy J, Schaeffer C, Diemer H, Van-Dorsselaer A, Fontecilla-Camps JC, Masson P, Rochu D, Chabrière E. Découverte et structure cristallographique d’une apolipoprotéine humaine. Annales Pharmaceutiques Françaises 2007; 65:98-107. [PMID: 17404543 DOI: 10.1016/s0003-4509(07)90023-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We report the serendipitous discovery of a human plasma phosphate binding protein (HPBP). This 38 kDa protein is co-purified with paraoxonase (PON1). The association between HPON1 and HPBP is modulated by phosphate and calcium concentrations. The HPBP X-ray structure solved at 1.9 A resolution is similar to the prokaryotic phosphate solute-binding proteins (SBPs) associated with ATP binding cassette transmembrane transporters, though phosphate-SBPs have never been characterized or predicted from nucleic acid databases in eukaryotes. However, HPBP belongs to the family of ubiquitous eukaryotic proteins named DING, meaning that phosphate-SBPs are also widespread in eukaryotes. The absence of complete genes for eukaryotic phosphate-SBP from databases is intriguing, but the astonishing 90% sequence conservation of genes between evolutionary distant species suggests that the corresponding proteins play an important function. HPBP is the first identified transporter capable of binding phosphate ions in human plasma. Thus it is thought to become a new predictor and a potential therapeutic agent for phosphate-related diseases such as atherosclerosis.
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Affiliation(s)
- R Morales
- Laboratoire de cristallogenèse et cristallographie des Protéines, Institut de Biologie Structurale J.-P. Ebel, F 38027 Grenoble
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Abstract
AIMS OF THE STUDY Respiratory-related evoked potentials (RREPs) are a method of recording brain activities in response to respiratory stimuli. Although data in childhood are scarce, the absence of the early P1 component of RREPs has been reported in children with a history of life-threatening asthma. This study was focused on the presence, latencies, and amplitudes of the P1, N1, P2, and N2 components of the RREPs in a paediatric series of asthmatic patients. PATIENTS AND METHODS RREPs were recorded in 21 patients with stable asthma, age range 8-17 years, 11 healthy children, age range 6-16 years, and 24 healthy adults, age range 20-28 years. The signals from left (C3-Cz) and right (C4-Cz) central (rolandic) location were recorded separately, using surface electrodes. Evoked responses to two series of 80 consecutive mid-inspiratory occlusions were averaged. Recordings were analysed manually. RESULTS All 4 RREPs components were significantly more often absent in asthmatic children than in healthy children and adults (P1, p=0.01; N1, p=0.008; P2, p=0.008, N2, p=0.01). The latencies and amplitudes of the four components were similar in patients and healthy subjects. CONCLUSION RREPs components were less frequently present in children with asthma than in healthy subjects. This finding should promote the recording of RREPs in other acute and chronic respiratory diseases in children in order to search for possible electroclinical correlations.
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Affiliation(s)
- F Nicot
- Unité Inserm U719, AP-HP, hôpital Armand-Trousseau, Paris, France
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Abstract
PURPOSE To assess ocular and clinical manifestations in patients with Möbius syndrome. METHODS Twenty-seven patients (26 infants and 1 adult) underwent prospective ophthalmic, clinical, neurological, otorhinological, orthopedic and electrophysiological assessment. Twenty-three patients underwent MRI and 20 patients genetic examination with karyotype. RESULTS Three of 27 patients with cranial nerve palsies did not satisfy the criteria for Möbius syndrome. All 24 patients with Möbius syndrome had facial palsy. Nineteen patients (79.2%) had limited abduction. Eleven patients (45.9%) presented with esotropia, five patients (20.8%) presented with exotropia or hypertropia. Cranial nerve impairment of the Vth, IXth, XIth, and XIIth nerves was noted in 20 patients (83.4%). Other signs were general motor disability in 14 patients (58.2%), orthopedic abnormalities in eight patients (33.3%), and otorhinological abnormalities in six patients (25%). Electromyographic studies of facial muscles revealed neuromuscular changes in all cases. MRI findings showed hypoplasia of facial nerves in two patients (8.3%). Chromosomal abnormalities were not found. One patient presented an inherited inversion of the sixth chromosome. CONCLUSION The diagnosis of Möbius syndrome may be difficult in some patients with atypical signs of facial diplegia and other cranial nerve palsies. When diagnosing Möbius syndrome, all ophthalmologic and clinical signs must be applied. Möbius syndrome is more than a cranial nerve or nuclear disorder. It is a syndrome of more complex lower brainstem involvement.
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Affiliation(s)
- M Momtchilova
- Service d'Ophtalmologie, Hôpital Armand Trousseau, Paris, France.
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Morales R, Berna A, Carpentier P, Contreras-Martel C, Renault F, Nicodeme M, Chesne-Seck ML, Bernier F, Dupuy J, Schaeffer C, Diemer H, Van-Dorsselaer A, Fontecilla-Camps JC, Masson P, Rochu D, Chabriere E. Serendipitous discovery and X-ray structure of a human phosphate binding apolipoprotein. Structure 2006; 14:601-9. [PMID: 16531243 DOI: 10.1016/j.str.2005.12.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 11/09/2005] [Accepted: 12/20/2005] [Indexed: 11/23/2022]
Abstract
We report the serendipitous discovery of a human plasma phosphate binding protein (HPBP). This 38 kDa protein is copurified with the enzyme paraoxonase. Its X-ray structure is similar to the prokaryotic phosphate solute binding proteins (SBPs) associated with ATP binding cassette transmembrane transporters, though phosphate-SBPs have never been characterized or predicted from nucleic acid databases in eukaryotes. However, HPBP belongs to the family of ubiquitous eukaryotic proteins named DING, meaning that phosphate-SBPs are also widespread in eukaryotes. The systematic absence of complete genes for eukaryotic phosphate-SBP from databases is intriguing, but the astonishing 90% sequence conservation between genes belonging to evolutionary distant species suggests that the corresponding proteins play an important function. HPBP is the only known transporter capable of binding phosphate ions in human plasma and may become a new predictor of or a potential therapeutic agent for phosphate-related diseases such as atherosclerosis.
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Affiliation(s)
- Renaud Morales
- Laboratoire de Cristallogenèse et Cristallographie des Protéines, Institut de Biologie Structurale JP EBEL, 38027 Grenoble, France
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Elias M, Rochu D, Renault F, Lecomte C, Masson P, Chabriere E. Associations between human paraoxonase and human phosphate binding protein. Acta Crystallogr A 2006. [DOI: 10.1107/s0108767306097285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Chabriere E, Morales R, Berna A, Carpentier P, Contreras-Martel C, Renault F, Nicodeme M, Chesne-Seck ML, Bernier F, Dupuy J, Schaeffer C, Diemer H, Van-Dorsselaer A, Fontecilla-Camps JC, Masson P, Rochu D. Serendipitous discovery of a human phosphate binding apolipoprotein. Acta Crystallogr A 2006. [DOI: 10.1107/s0108767306099508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Maystadt I, Zarhrate M, Leclair-Richard D, Estournet B, Barois A, Renault F, Routon MC, Durand MC, Lefebvre S, Munnich A, Verellen-Dumoulin C, Viollet L. A gene for an autosomal recessive lower motor neuron disease with childhood onset maps to 1p36. Neurology 2006; 67:120-4. [PMID: 16728649 DOI: 10.1212/01.wnl.0000223834.55225.2d] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To describe the clinical features of a novel variant of autosomal recessive lower motor neuron disease (LMND) with childhood onset and to map the disease-causing gene. METHODS The authors performed a clinical study in a large consanguineous African family. After linkage exclusion to SMN1 and SOD1 loci, they performed a genome-wide linkage analysis to map the underlying genetic defect. RESULTS This novel variant of LMND with childhood onset and autosomal recessive mode of inheritance is characterized by a progressive symmetric and generalized involvement of the musculature. Four of the five affected patients had muscle weakness since age 3, strongly worsening during childhood and leading to generalized tetraplegia in adulthood. Genetic analyses using homozygosity mapping strategy assigned this progressive generalized LMND locus to an interval of 3.9 cM (or 1.5 megabases) on chromosome 1p36, between loci D1S508 and D1S2633 (Z(max) = 3.79 at theta = 0.00 at locus D1S253). This region encloses 27 candidate genes. CONCLUSION Genetic mapping of a novel rare phenotype of lower motor neuron disease opens the way toward the identification of a new gene involved in motor neuron degeneration, located in the 1p36 chromosomal region.
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Affiliation(s)
- I Maystadt
- Unité de Recherches sur les Handicaps Génétiques de l'Enfant, INSERM U393, Hôpital Necker Enfants Malades, 149 rue de Sèvres, F-75743 Paris Cedex 15, France
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Renault F, Chabrière E, Andrieu JP, Dublet B, Masson P, Rochu D. Tandem purification of two HDL-associated partner proteins in human plasma, paraoxonase (PON1) and phosphate binding protein (HPBP) using hydroxyapatite chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 836:15-21. [PMID: 16595195 DOI: 10.1016/j.jchromb.2006.03.029] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Revised: 03/06/2006] [Accepted: 03/10/2006] [Indexed: 12/20/2022]
Abstract
Human plasma paraoxonase (PON1) is calcium-dependent enzyme that hydrolyses esters, including organophosphates and lactones, and exhibits anti-atherogenic properties. Human phosphate binding protein (HPBP) was discovered as contaminant during crystallization trials of PON1. This observation and uncertainties for the real activities of PON1 led us to re-evaluate the purity of PON1 preparations. We developed a hydroxyapatite chromatography for the separation of both HDL-associated proteins. We confirmed that: (1) HPBP is strongly associated to PON1 in HDL, and generally both proteins are co-purified; (2) standard purification protocols of PON1 lead to impure enzyme; (3) hydroxyapatite chromatography allows the simultaneous purification of PON1 and HPBP.
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Affiliation(s)
- Frédérique Renault
- Unité d'Enzymologie, Département de Toxicologie, Centre de Recherches du Service de Santé des Armées, 38702 La Tronche Cedex, France
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23
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Rochu D, Cléry-Barraud C, Renault F, Chevalier A, Bon C, Masson P. Capillary electrophoresis versus differential scanning calorimetry for the analysis of free enzyme versus enzyme-ligand complexes: in the search of the ligand-free status of cholinesterases. Electrophoresis 2006; 27:442-51. [PMID: 16342323 DOI: 10.1002/elps.200500517] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cholinesterases (ChEs) are highly efficient biocatalysts whose active site is buried in a deep, narrow gorge. The talent of CE to discover inhibitors in the gorge of highly purified preparations has fairly altered the meaning of a ChE ligand-free status. To attempt at a description of this one, we investigated the stability of Bungarus fasciatus acetylcholinesterase (AChE), alone or complexed with different inhibitors. Determination of mid-transition temperature for thermal denaturation, using differential scanning calorimetry (DSC) and CE, provided conflicting results. Discrepancies strongly question the reality of a ligand-free AChE state. DSC allowed estimation of the stability of AChE-ligands complexes, and to rank the stabilizing effect of different inhibitors. CE acted as a detector of hidden ligands, provided that they were charged, reversibly bound, and thus dissociable upon action of electric fields. Then, CE allowed quantification of the stability of ligand-free AChE. CE and DSC providing each fractional and nonredundant information, cautious attention must be paid for actual estimation of the conformational stability of ChEs. Because inhibitors used in purification of ChEs by affinity chromatography are charged, CE remains a leading method to estimate enzyme stability and detect the presence of bound hidden ligands.
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Affiliation(s)
- Daniel Rochu
- Centre de Recherches du Service de Santé des Armées, La Tronche, France.
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24
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Contreras-Martel C, Carpentier P, Morales R, Renault F, Chesne-Seck ML, Rochu D, Masson P, Fontecilla-Camps JC, Chabrière E. Crystallization and preliminary X-ray diffraction analysis of human phosphate-binding protein. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:67-9. [PMID: 16511265 PMCID: PMC2150935 DOI: 10.1107/s1744309105041461] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Accepted: 12/11/2005] [Indexed: 11/11/2022]
Abstract
Human phosphate-binding protein (HPBP) was serendipitously discovered by crystallization and X-ray crystallography. HPBP belongs to a eukaryotic protein family named DING that is systematically absent from the genomic database. This apoprotein of 38 kDa copurifies with the HDL-associated apoprotein paraoxonase (PON1) and binds inorganic phosphate. HPBP is the first identified transporter capable of binding phosphate ions in human plasma. Thus, it may be regarded as a predictor of phosphate-related diseases such as atherosclerosis. In addition, HPBP may be a potential therapeutic protein for the treatment of such diseases. Here, the purification, detergent-exchange protocol and crystallization conditions that led to the discovery of HPBP are reported.
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Affiliation(s)
- Carlos Contreras-Martel
- Laboratoire de Cristallogenèse et Cristallographie des Protéines, Institut de Biologie Structurale J.-P. Ebel, 38027 Grenoble, France
| | - Philippe Carpentier
- Laboratoire de Cristallogenèse et Cristallographie des Protéines, Institut de Biologie Structurale J.-P. Ebel, 38027 Grenoble, France
| | - Renaud Morales
- Laboratoire de Cristallogenèse et Cristallographie des Protéines, Institut de Biologie Structurale J.-P. Ebel, 38027 Grenoble, France
| | - Frédérique Renault
- Unité d’Enzymologie, Département de Toxicologie, Centre de Recherches du Service de Santé des Armées, 38702 La Tronche, France
| | - Marie-Laure Chesne-Seck
- Laboratoire de Cristallographie Macromoléculaire, Institut de Biologie Structurale J.-P. Ebel, 38027 Grenoble, France
| | - Daniel Rochu
- Unité d’Enzymologie, Département de Toxicologie, Centre de Recherches du Service de Santé des Armées, 38702 La Tronche, France
| | - Patrick Masson
- Unité d’Enzymologie, Département de Toxicologie, Centre de Recherches du Service de Santé des Armées, 38702 La Tronche, France
| | - Juan Carlos Fontecilla-Camps
- Laboratoire de Cristallogenèse et Cristallographie des Protéines, Institut de Biologie Structurale J.-P. Ebel, 38027 Grenoble, France
| | - Eric Chabrière
- Unité d’Enzymologie, Département de Toxicologie, Centre de Recherches du Service de Santé des Armées, 38702 La Tronche, France
- Laboratoire de Cristallographie et Modélisation des Matériaux Minéraux et Biologiques, CNRS–Université Henri Poincaré, 54506 Vandoeuvre-lès-Nancy, France
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25
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Chabriere E, Morales R, Berna A, Carpentier P, Contreras-Martel C, Renault F, Nicodeme M, Chesne-Seck ML, Bernier F, Shaeffer C, Diemer H, Van-Dorsselaer A, Fontecilla-Camps JC, Masson P, Rochu D. Serendipitous discovery and X-ray structure of a human phosphate binding apolipoprotein. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305088744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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26
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Gabel F, Weik M, Masson P, Renault F, Fournier D, Brochier L, Doctor BP, Saxena A, Silman I, Zaccai G. Effects of soman inhibition and of structural differences on cholinesterase molecular dynamics: a neutron scattering study. Biophys J 2005; 89:3303-11. [PMID: 16100272 PMCID: PMC1366826 DOI: 10.1529/biophysj.105.061028] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Incoherent elastic neutron scattering experiments on members of the cholinesterase family were carried out to investigate how molecular dynamics is affected by covalent inhibitor binding and by differences in primary and quaternary structure. Tetrameric native and soman-inhibited human butyrylcholinesterase (HuBChE) as well as native dimeric Drosophila melanogaster acetylcholinesterase (DmAChE) hydrated protein powders were examined. Atomic mean-square displacements (MSDs) were found to be identical for native HuBChE and for DmAChE in the whole temperature range examined, leading to the conclusion that differences in activity and substrate specificity are not reflected by a global modification of subnanosecond molecular dynamics. MSDs of native and soman-inhibited HuBChE were identical below the thermal denaturation temperature of the native enzyme, indicating a common mean free-energy surface. Denaturation of the native enzyme is reflected by a relative increase of MSDs consistent with entropic stabilization of the unfolded state. The results suggest that the stabilization of HuBChE phosphorylated by soman is due to an increase in free energy of the unfolded state due to a decrease in entropy.
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Affiliation(s)
- F Gabel
- Laboratoire de Biophysique Moléculaire, Institut de Biologie Structurale, 41 rue Jules Horowitz, F-38027 Grenoble Cedex 1, France
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27
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Laville M, Renault F. [How to manage my patients' psychological disturbances?]. Ann Endocrinol (Paris) 2005; 66:2S46-9. [PMID: 15959396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Psychological disturbances are frequently encountered in obese patients. The physician specialised in nutrition should take them into account within the therapeutic project and all along the patient's management. This review describe, according to the main obese patients' profiles (typology), the conditions for an optimal adequation between hopes and expectations from both the patient and the physician, as well as the psychiatrist role within the therapeutic project and during the management period.
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Affiliation(s)
- M Laville
- Service d'Endocrinologie Diabétologie-Nutrition. Hôpital Edouard Herriot, Lyon, France.
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28
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Chneiweiss H, Mondet C, Coulombel L, Renault F, Varlet P, Daumas-Duport C. Mise en évidence de cellules souches tumorales au sein des tumeurs glio-neuronales malignes (TGNM). Neurochirurgie 2005. [DOI: 10.1016/s0028-3770(05)83438-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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29
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Gabel F, Weik M, Doctor BP, Saxena A, Fournier D, Brochier L, Renault F, Masson P, Silman I, Zaccai G. The influence of solvent composition on global dynamics of human butyrylcholinesterase powders: a neutron-scattering study. Biophys J 2004; 86:3152-65. [PMID: 15111428 PMCID: PMC1304180 DOI: 10.1016/s0006-3495(04)74363-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A major result of incoherent elastic neutron-scattering experiments on protein powders is the strong dependence of the intramolecular dynamics on the sample environment. We performed a series of incoherent elastic neutron-scattering experiments on lyophilized human butyrylcholinesterase (HuBChE) powders under different conditions (solvent composition and hydration degree) in the temperature range from 20 to 285 K to elucidate the effect of the environment on the enzyme atomic mean-square displacements. Comparing D(2)O- with H(2)O-hydrated samples, we were able to investigate protein as well as hydration water molecular dynamics. HuBChE lyophilized from three distinct buffers showed completely different atomic mean-square displacements at temperatures above approximately 200 K: a salt-free sample and a sample containing Tris-HCl showed identical small-amplitude motions. A third sample, containing sodium phosphate, displayed highly reduced mean-square displacements at ambient temperature with respect to the other two samples. Below 200 K, all samples displayed similar mean-square displacements. We draw the conclusion that the reduction of intramolecular protein mean-square displacements on an Angstrom-nanosecond scale by the solvent depends not only on the presence of salt ions but also on their type.
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Affiliation(s)
- F Gabel
- Laboratoire de Biophysique Moléculaire, Institut de Biologie Structurale, Grenoble, France
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30
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Rochu D, Viguié N, Renault F, Crouzier D, Froment MT, Masson P. Contribution of the active-site metal cation to the catalytic activity and to the conformational stability of phosphotriesterase: temperature- and pH-dependence. Biochem J 2004; 380:627-33. [PMID: 15018612 PMCID: PMC1224221 DOI: 10.1042/bj20031861] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2003] [Revised: 03/11/2004] [Accepted: 03/12/2004] [Indexed: 11/17/2022]
Abstract
Phosphotriesterase (PTE) detoxifies nerve agents and organophosphate pesticides. The two zinc cations of the PTE active centre can be substituted by other transition metal cations without loss of activity. Furthermore, metal-substituted PTEs display differences in catalytic properties. A prerequisite for engineering highly efficient mutants of PTE is to improve their thermostability. Isoelectric focusing, capillary electrophoresis and steady-state kinetics analysis were used to determine the contribution of the active-site cations Zn2+, Co2+ or Cd2+ to both the catalytic activity and the conformational stability of the corresponding PTE isoforms. The three isoforms have different pI values (7.2, 7.5 and 7.1) and showed non-superimposable electrophoretic titration curves. The overall structural alterations, causing changes in functional properties, were found to be related to the nature of the bound cation: ionic radius and ion electronegativity correlate with Km and kcat respectively. In addition, the pH-dependent activity profiles of isoforms were different. The temperature-dependent profiles of activity showed maximum activity at T < or =35 degrees C, followed by an activation phase near 45-48 degrees C and then inactivation which was completed at 60 degrees C. Analysis of thermal denaturation of the PTEs provided evidence that the activation phase resulted from a transient intermediate. Finally, at the optimum activity between pH 8 and 9.4, the thermostability of the different PTEs increased as the pH decreased, and the metal cation modulated stability (Zn2+-, Co2+- and Cd2+-PTE showed different T (m) values of 60.5-67 degrees C, 58-64 degrees C and 53-64 degrees C respectively). Requirements for optimum activity of PTE (displayed by Co2+-PTE) and maximum stability (displayed by Zn2+-PTE) were demonstrated.
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Affiliation(s)
- Daniel Rochu
- Unité d'Enzymologie, Centre de Recherches du Service de Santé des Armées, BP 87, 38702 La Tronche cedex, France.
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31
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Renault F. [The role of electrodiagnostic studies in the diagnosis of hypotonia in infancy]. Rev Med Liege 2004; 59 Suppl 1:190-7. [PMID: 15244176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Increased muscle extensibility and passivity characterize infantile hypotonia. It may reveal a peripheral neuromuscular disease as well as a disorder of the central nervous system. Electrodiagnostic studies in newborn and young infants are useful to guide the indication of other complementary investigations. Signs of denervation on needle electromyography strongly suggest infantile spinal muscular atrophy. Electrodiagnostic findings can distinguish rare conditions mimicking spinal muscular atrophy that are obstetrical tetraplegia and severe congenital neuropathies. Nerve conduction velocities are severely slowed in hereditary sensorimotor neuropathies and neurodegenerative disorders. Myopathic changes on needle electromyography are associated with congenital muscular dystrophies and structural or metabolic congenital myopathies. In congenital myotonic dystrophy, myotonic discharges can be recorded in the infant as well as in his/her mother. Myopathic changes may also be detected in collagen disorders, in cases of muscular atrophy secondary to hypomotility or malnutrition, and in patients with congenital myasthenic syndrome. Repetitive nerve stimulations are required to characterize myasthenic syndromes. Finally, normal results of electrodiagnostic studies constitute a relevant information that moves diagnostic procedures to search for central nervous system disorders. Benign congenital hypotonia is a quite rare condition that is diagnosed retrospectively, when hypotonia is strictly isolated and recovers completely before 2 years of age.
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Affiliation(s)
- F Renault
- Unité de Neurophysiologie Clinique, Hôpital d'enfants Armand-Trousseau, Paris 12, France.
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32
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Sharif A, Renault F, Beuvon F, Castellanos R, Canton B, Barbeito L, Junier MP, Chneiweiss H. The expression of PEA-15 (phosphoprotein enriched in astrocytes of 15 kDa) defines subpopulations of astrocytes and neurons throughout the adult mouse brain. Neuroscience 2004; 126:263-75. [PMID: 15207344 DOI: 10.1016/j.neuroscience.2004.02.039] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2004] [Indexed: 12/20/2022]
Abstract
Phosphoprotein enriched in astrocytes of 15 kDa (PEA-15) is an abundant phosphoprotein in primary cultures of mouse brain astrocytes. Its capability to interact with members of the apoptotic and mitogen activated protein (MAP) kinase cascades endows PEA-15 with anti-apoptotic and anti-proliferative properties. We analyzed the in vivo cellular sources of PEA-15 in the normal adult mouse brain using a novel polyclonal antibody. Immunohistochemical assays revealed numerous PEA-15-immunoreactive cells throughout the brain of wild-type adult mice while no immunoreactive signal was observed in the brain of PEA-15 -/- mice. Cell morphology and double immunofluorescent staining showed that both astrocytes and neurons could be cellular sources of PEA-15. Closer examination revealed that in a given area only part of the astrocytes expressed the protein. The hippocampus was the most striking example of this heterogeneity, a spatial segregation restricting PEA-15 positive astrocytes to the CA1 and CA3 regions. A PEA-15 immunoreactive signal was also observed in a few cells within the subventricular zone and the rostral migratory stream. In vivo analysis of an eventual PEA-15 regulation in astrocytes was performed using a model of astrogliosis occurring along motor neurons degeneration, the transgenic mouse expressing the mutant G93A human superoxyde-dismutase-1, a model of amyotrophic lateral sclerosis. We observed a marked up-regulation of PEA-15 in reactive astrocytes that had developed throughout the ventral horn of the lumbar spinal cord of the transgenic mice. The heterogeneous cellular expression of the protein and its increased expression in pathological situations, combined with the known properties of PEA-15, suggest that PEA-15 expression is associated with a particular metabolic status of cells challenged with potentially apoptotic and/or proliferative signals.
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Affiliation(s)
- A Sharif
- INSERM U114, Chaire de Neuropharmacologie, Collège de France, 11 Place M. Berthelot, 75231 Paris, Cedex 05, France
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33
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Fokine A, Morales R, Contreras-Martel C, Carpentier P, Renault F, Rochu D, Chabriere E. Direct phasing at low resolution of a protein copurified with human paraoxonase (PON1). Acta Crystallogr D Biol Crystallogr 2003; 59:2083-7. [PMID: 14646065 DOI: 10.1107/s0907444903017682] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2003] [Accepted: 08/08/2003] [Indexed: 11/10/2022]
Abstract
In this paper, the low-resolution structure of a previously unknown protein copurified with human paraoxonase (PON1) is reported. The structure of this protein was very difficult to solve using classical crystallographic methods. Progress was made using a new phasing method based on topological analysis. From the experimental point of view, this method has the advantage of requiring only a simple low-resolution X-ray data set. The program used and the different steps of the data-processing and phasing procedure are described. The results provided an insight into the failure of previous molecular-replacement attempts. The low-resolution shape of the protein which was presented with confidence is compared with and confirmed by the structure at 1.8 A solved subsequently using classical methods. This work shows that this direct-phasing method could be used systematically in difficult cases: it provides low-resolution structural information comparable with that obtainable by electron microscopy.
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Affiliation(s)
- A Fokine
- Laboratoire de Cristallographie et Modélisation des Matériaux Minéraux et Biologiques, Unité Mixte de Recherche 7036 CNRS, Université Henri Poincaré Nancy I, BP 239, 54506 Vandoeuvre-lès-Nancy, France
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34
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Renault F. Pediatric clinical EMG challenge with bulbar dysfunction. Suppl Clin Neurophysiol 2003; 53:139-47. [PMID: 12740988 DOI: 10.1016/s1567-424x(09)70149-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Affiliation(s)
- F Renault
- Unité de Neurophysiologie Clinique, Hôpital d'Enfants Armand-Trousseau, 28 Avenue du Docteur Arnold-Netter, 75571 Paris, 12, France.
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35
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Josse D, Ebel C, Stroebel D, Fontaine A, Borges F, Echalier A, Baud D, Renault F, Le Maire M, Chabrieres E, Masson P. Oligomeric states of the detergent-solubilized human serum paraoxonase (PON1). J Biol Chem 2002; 277:33386-97. [PMID: 12080042 DOI: 10.1074/jbc.m200108200] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human plasma paraoxonase (HuPON1) is a high density lipoprotein (HDL)-bound enzyme exhibiting antiatherogenic properties. The molecular basis for the binding specificity of HuPON1 to HDL has not been established. Isolation of HuPON1 from HDL requires the use of detergents. We have determined the activity, dispersity, and oligomeric states of HuPON1 in solutions containing mild detergents using nondenaturing electrophoresis, size exclusion chromatography, and cross-linking. HuPON1 was active whatever its oligomeric state. In nonmicellar solutions, HuPON1 was polydisperse. In contrast, HuPON1 exhibited apparent homogeneity in micellar solutions, except with CHAPS. The enzyme apparent hydrodynamic radius varied with the type of detergent and protein concentration. In C(12)E(8) micellar solutions, from sedimentation velocity, equilibrium analytical ultracentrifugation, and radioactive detergent binding, HuPON1 was described as monomers and dimers in equilibrium. A decrease of the detergent concentration shifted this equilibrium toward the formation of dimers. About 100 detergent molecules were associated per monomer and dimer. The assembly of amphiphilic molecules, phospholipids in vivo, in sufficiently large aggregates could be a prerequisite for anchoring of HuPON1 and then allowing stabilization of the enzyme activity. Changes of HDL size and shape could strongly affect the binding affinity and stability of HuPON1 and result in reduced antioxidative capacity of the lipoprotein.
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Affiliation(s)
- Denis Josse
- Unité d'Enzymologie, Centre de Recherches du Service de Santé des Armées, 24 avenue des Maquis du Grésivaudan, BP 87, 38702 La Tronche Cedex, France.
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36
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Rochu D, Renault F, Masson P. Detection of unwanted protein-bound ligands by capillary zone electrophoresis: the case of hidden ligands that stabilize cholinesterase conformation. Electrophoresis 2002; 23:930-7. [PMID: 11920879 DOI: 10.1002/1522-2683(200203)23:6<930::aid-elps930>3.0.co;2-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Detection, identification and characterization of compounds present in purified proteins and biopharmaceuticals are of central interest. As well as chemical remedies, proteins of pharmacological interest have to exhibit their nakedness to become therapeutic drugs. Cholinesterases (ChE) are enzymes of major importance for detoxification of poisonous esters. Likewise, ChE are characterized by the high catalytic efficiency of an active site positioned at the bottom of a deep gorge. The gorge can be partially or fully occupied by ligands, i.e., substrates and inhibitors that are currently used in affinity chromatography purification steps. Accordingly, a suitable method allowing to analyse the presence of unwanted ligands and its influence on the functional conformation and stability of these enzymes was essential. We have developed CZE approaches for that purpose. The factors causing discrepancies between data for thermal unfolding of ChE by electrophoretic and by calorimetric methods were investigated. The presence of unwanted hidden ligands bound to purified enzymes was first demonstrated. The incidence of these ligands was discussed. Altogether, our results raised several questions concerning the real conformation of the native state of enzymes. Finally, CZE was proved to be a pertinent tool to validate the conformity of purified enzymes to a status of biopharmaceutical.
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Affiliation(s)
- Daniel Rochu
- Unité d'Enzymologie, Centre de Recherches du Service de Santé des Armées, BP 87, F-38702 La Tronche Cedex, France.
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37
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Rochu D, Beaufet N, Renault F, Viguié N, Masson P. The wild type bacterial Co(2+)/Co(2+)-phosphotriesterase shows a middle-range thermostability. Biochim Biophys Acta 2002; 1594:207-18. [PMID: 11904217 DOI: 10.1016/s0005-2728(01)00224-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The phosphotriesterase (PTE) from Pseudomonas diminuta, a metalloenzyme that catalyses the hydrolysis of organophosphorus pesticides and nerve agents, has been described as a remarkably heat-stable protein [Grimsley et al., Biochemistry 36 (1997), 14366-14374]. Because substitution of the naturally occurring zinc ions by cobalt ions was found to enhance the enzyme catalytic activity, we investigated the thermal stability of the Co(2+)/Co(2+)-PTE. This study, carried out using capillary electrophoresis under optimised conditions in the pH range 9-10 compatible with optimal enzyme activity, provided evidence for irreversible denaturation according to the Lumry-Eyring model. A temperature-induced conformational transition (T(m) approximately equal to 58 degrees C) and an early growing of aggregates were observed. Comparison of UV spectra with heat-induced inactivation data clearly demonstrated that the PTE state populated above T(m) was neither native nor active. Differential scanning calorimetry showed only an exothermic trace due to aggregation of the denatured protein at T=76 degrees C. Accordingly, the temperature-induced denaturation process of the PTE could be described by a consecutive reaction model, including formation of an intermediate with enhanced activity at T approximately equal to 45 degrees C and an inactive unfolded state populated at T approximately equal to 58 degrees C, which leads to denatured aggregates. Thus, the wild type Co(2+)/Co(2+)-PTE displays a middle-range thermostability. Hence, for decontamination purposes under extreme Earth temperatures, wild type and engineered mutants of PTE substituted with other metal cations should be evaluated.
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Affiliation(s)
- Daniel Rochu
- Unité d'Enzymologie, Centre de Recherches du Service de Santé des Armées, P.O. Box 87, 38702 La Tronche Cedex, France.
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38
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Weingand-Ziade A, Ribes F, Renault F, Masson P. Pressure- and heat-induced inactivation of butyrylcholinesterase: evidence for multiple intermediates and the remnant inactivation process. Biochem J 2001; 356:487-93. [PMID: 11368776 PMCID: PMC1221860 DOI: 10.1042/0264-6021:3560487] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The inactivation process of native (N) human butyrylcholinesterase (BuChE) by pressure and/or heat was found to be multi-step. It led to irreversible formation of an active intermediate (I) state and a denatured state. This series-inactivation process was described by expanding the Lumry-Eyring [Lumry, R. and Eyring, H. (1954) J. Phys. Chem. 58, 110-120] model. The intermediate state (I) was found to have a K(m) identical with that of the native state and a turnover rate (k(cat)) twofold higher than that of the native state with butyrylthiocholine as the substrate. The increased catalytic efficiency (k(cat)/K(m)) of I can be explained by a conformational change in the active-site gorge and/or restructuring of the water-molecule network in the active-site pocket, making the catalytic steps faster. However, a pressure/heat-induced covalent modification of native BuChE, affecting the catalytic machinery, cannot be ruled out. The inactivation process of BuChE induced by the combined action of pressure and heat was found to continue after interruption of pressure/temperature treatment. This secondary inactivation process was termed 'remnant inactivation'. We hypothesized that N and I were in equilibrium with populated metastable N' and I' states. The N' and I' states can either return to the active forms, N and I, or develop into inactive forms, N(')(in) and I(')(in). Both active N' and I' intermediate states displayed different rates of remnant inactivation depending on the pressure and temperature pretreatments and on the storage temperature. A first-order deactivation model describing the kinetics of the remnant inactivation of BuChE is proposed.
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Affiliation(s)
- A Weingand-Ziade
- Centre de Recherches du Service de Santé des Armées, Unité d'Enzymologie, BP 87, 38702 La Tronche Cédex, France
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Affiliation(s)
- F Renault
- Unité de Neurophysiologie Clinique, Hĵpital d'Enfants Armand-Trousseau, Paris, France.
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Rochu D, Pernet T, Renault F, Bon C, Masson P. Dual effect of high electric field in capillary electrophoresis study of the conformational stability of Bungarus fasciatus acetylcholinesterase. J Chromatogr A 2001; 910:347-57. [PMID: 11261729 DOI: 10.1016/s0021-9673(00)01211-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The effect of high electric field in capillary zone electrophoresis (CZE) was evaluated for the study of the thermally induced unfolding of Bungarus fasciatus acetylcholinesterase. This monomer enzyme is characterised by two interdependent uncommon structural features, the asymmetrical distribution of charged residues and a relatively low thermal denaturation temperature. Both traits were presumed to interfere in the thermal unfolding of this enzyme as investigated by CZE. This paper analyses the effect of high electric field on the behaviour of the enzyme native state. It is shown that increasing the applied field causes denaturation-like transition of the enzyme at a current power which does not induce excessive Joule heating in the capillary. The susceptibility to electric field of proteins like cholinesterases, with charge distribution anisotropy, large permanent dipole moment and notable molecular flexibility associated with moderate thermal stability, was subsequently discussed.
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Affiliation(s)
- D Rochu
- Unité d'Enzymologie, Centre de Recherches du Service de Santé des Armées, La Tronche, France.
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Lallement G, Renault F, Baubichon D, Peoc'h M, Burckhart MF, Galonnier M, Clarençon D, Jourdil N. Compared efficacy of diazepam or avizafone to prevent soman-induced electroencephalographic disturbances and neuropathology in primates: relationship to plasmatic benzodiazepine pharmacokinetics. Arch Toxicol 2000; 74:480-6. [PMID: 11097386 DOI: 10.1007/s002040000146] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We performed an experiment to characterize the toxicity of soman in cynomolgus monkeys in which organophosphorus intoxication was followed by treatment with either the current three-drug therapy atropine/pralidoxime/diazepam or a combination of atropine/pralidoxime/avizafone, avizafone being the water soluble prodrug of diazepam. Clinical, electrophysiological, and histological approaches were combined. When benzodiazepines were injected at the similar molar dose of 0.7 micromol/kg, the protection against soman toxicity was better with the atropine/ pralidoxime/diazepam combination than with the atropine/pralidoxime/avizafone one. Pharmacokinetic studies demonstrated that this difference of efficacy could be explained by a lower plasmatic load of diazepam obtained after injection of avizafone at 0.7 micromol/kg, compared to the administration of diazepam at the same molar dose. Moreover, after injection of avizafone, plasmatic levels of diazepam were achieved faster and declined more rapidly than after administration of diazepam. Compared to diazepam given at a dose of 0.7 micromol/kg, injection of 1 micromol avizafone/kg gave a similar plasmatic load of benzodiazepine, but with a lower time to maximum plasma concentration (tmax) and a higher maximum plasma concentration (Cmax) for plasmatic diazepam. We therefore went on to demonstrate that administration of the atropine/pralidoxime/avizafone combination at a dose 1 micromol benzodiazepine/kg to intoxicated monkeys afforded electrophysiological and histological protection similar to that obtained after administration of atropine/pralidoxime/diazepam at a dose of 0.7 micromol diazepam/kg. Reflections on the possible incorporation of avizafone in three-drug emergency treatment are presented.
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Affiliation(s)
- G Lallement
- Unité de Neuropharmacologie, CRSSA, La Tronche, France.
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Abstract
Polysomnography, electromyography (EMG) of the face, tongue, and soft palate, blink reflexes (BRs), EMG during bottle-feeding, and brainstem auditory evoked responses (BAERs) were performed in 25 newborn babies with isolated Pierre Robin sequence (PRS) to aid in evaluation and management. Obstructive apneas were found in 23/24 patients (the 25th having undergone tracheotomy). Number and duration of central respiratory pauses were always normal, as well as electroencephalographic and clinical organization of sleep stages. EMG recruitment pattern in facial and lingual muscles, and BRs were normal in all cases. EMG recruitment pattern in muscles of the soft palate was normal in 14/25 patients, showed a reduced average amplitude with short-duration and low amplitude motor unit potentials in 10/25, and showed signs of denervation in 1/25. EMG during bottle-feeding showed sucking-swallowing disorders in 20/25 patients. BAERs showed a bilateral conductive impairment with increased latencies and thresholds in 5/19 patients, but with normal and symmetric I-III and I-V interpeak latencies in 19/19. These neurophysiological findings suggest that in isolated PRS a dysfunction of the lingual and pharyngeal motor organization exists without any structural impairment in brainstem nuclei and pathways.
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Affiliation(s)
- F Renault
- Unité de neurophysiologie clinique, Hôpital d'enfants Armand-Trousseau, Paris, France.
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Weingand-Ziadé A, Renault F, Masson P. Differential effect of pressure and temperature on the catalytic behaviour of wild-type human butyrylcholinesterase and its D70G mutant. Eur J Biochem 1999; 264:327-35. [PMID: 10491076 DOI: 10.1046/j.1432-1327.1999.00609.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The combined action of temperature (10-35 degrees C) and pressure (0. 001-2 kbar) on the catalytic activity of wild-type human butyrylcholinesterase (BuChE) and its D70G mutant was investigated at pH 7.0 using butyrylthiocholine as the substrate. The residue D70, located at the mouth of the active site gorge, is an essential component of the peripheral substrate binding site of BuChE. Results showed a break in Arrhenius plots of wild-type BuChE (at Tt approximately 22 degrees C) whatever the pressure (dTt/dP = 1.6 +/- 1.5 degrees C.kbar-1), whereas no break was observed in Arrhenius plots of the D70G mutant. These results suggested a temperature-induced conformational change of the wild-type BuChE which did not occur for the D70G mutant. For the wild-type BuChE, at around a pressure of 1 kbar, an intermediate state, whose affinity for substrate was increased, appeared. This intermediate state was not seen for the mutant enzyme. The wild-type BuChE remained active up to a pressure of 2 kbar whatever the temperature, whereas the D70G mutant was found to be more sensitive to pressure inactivation (at pressures higher than 1.5 kbar the mutant enzyme lost its activity at temperatures lower than 25 degrees C). The results indicate that the residue D70 controls the conformational plasticity of the active site gorge of BuChE, and is involved in regulation of the catalytic activity as a function of temperature.
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Affiliation(s)
- A Weingand-Ziadé
- Centre de Recherches du Service de Santé des Armées, Unité d'Enzymologie, La Tronche, France
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Josse D, Xie W, Renault F, Rochu D, Schopfer LM, Masson P, Lockridge O. Identification of residues essential for human paraoxonase (PON1) arylesterase/organophosphatase activities. Biochemistry 1999; 38:2816-25. [PMID: 10052953 DOI: 10.1021/bi982281h] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Human serum paraoxonase (PON1) is a calcium-dependent organophosphatase. To identify residues essential for PON1 activity, we adopted complementary approaches based on chemical modification and site-directed mutagenesis. To detect 45Ca2+ binding to native and chemically modified PON1, we performed nondenaturating gel electrophoresis. The environment of calcium-binding sites was probed using the Ca2+ analogue, terbium. Tb3+ binds to calcium-binding sites as shown by displacement of 45Ca2+ by Tb3+. Binding of Tb3+ is accompanied by a complete loss of enzyme activity. PON1 chemical modification with the Trp-selective reagent, N-bromosuccinimide, and the Asp/Glu-selective, dicyclohexylcarbodiimide, established that Trp and Asp/Glu residues are components of the PON1 active center and calcium-binding sites. Additional evidence for the presence of a Trp residue in the PON1 calcium-binding sites was a characteristic fluorescence emission at 545 nm from the PON1-Tb3+ complex and abolishment of that fluorescence upon modification by N-bromosuccinimide. The importance of aromatic/hydrophobic character of the residue 280 was demonstrated by site-directed mutagenesis: the W280F mutant was fully active while the W280A and W280L mutants had markedly reduced activity. Twelve amino acids among conserved His and Asp/Glu residues were found essential for PON1 arylesterase and organophosphatase activities: H114, H133, H154, H242, H284, D53, D168, D182, D268, D278, E52, and E194. Finally, the cysteines constituting the PON1 disulfide bond (C41 and C352) were essential, but the glycan chains linked to Asn 252 and 323 were not essential for PON1 secretion and activity.
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Affiliation(s)
- D Josse
- Unité d'enzymologie, Centre de Recherches du Service de Santé des Armées, La Tronche, France.
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Abstract
We describe the electrophysiological findings in 2 infants with deficient cobalamin intake. After normal development, psychomotor regression appeared after the 6th month, leading to severe hypotonia and apathy before the 12th month. Electrodiagnostic evaluation showed sensory neuropathy in both cases, associated with motor neuropathy in 1 case. Thus, in an acquired floppy infant syndrome, electrophysiological signs of peripheral neuropathy contributed to the diagnosis of a curable metabolic disorder.
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Affiliation(s)
- F Renault
- Service de neurophysiologie clinique de l'enfant, hôpital Armand-Trousseau, Paris, France
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Rochu D, Rothlisberger C, Taupin C, Renault F, Gagnon J, Masson P. Purification, molecular characterization and catalytic properties of a Pseudomonas fluorescens enzyme having cholinesterase-like activity. Biochim Biophys Acta 1998; 1385:126-38. [PMID: 9630567 DOI: 10.1016/s0167-4838(98)00042-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An enzyme with a cholinesterase (ChE) activity, produced by Pseudomonas fluorescens, was purified to homogeneity in a three-step procedure. Analysis by non-denaturing and SDS-PAGE, and by isoelectric focusing, indicated that the enzyme was a monomer of 43 kDa, with a pI of 6.1. The N-terminal sequence, AEPLKAVGAGEGQLDIVAWPGYIEA, showed some similarities with proteins of the ChE family and a strong similarity with a protein from Escherichia coli with unknown structure and function. Cholinesterase activity at pH 7.0 and 25 degreesC was maximum with propionylthiocholine as substrate (kcat,app=670 min-1), followed by acetylthiocholine, and significantly lower with butyrylthiocholine. Catalytic specificity (kcat/Km) was the same for propionylthiocholine and acetylthiocholine, but was two orders of magnitude lower for butyrylthiocholine. Kinetics of thiocholine ester hydrolysis showed inhibition by excess substrate which was ascribed to binding of a second substrate molecule, leading to non-productive ternary complex (Km=35 microM, KSS=0.49 mM with propionylthiocholine). There was low or no reactivity with organophosphates and carbamates. The enzyme inhibited by echothiophate (kII=0.44x102 M-1 min-1) was not reactivated by pralidoxime methiodide. However, the P. fluorescens enzyme had affinity for procainamide and decamethonium, two reversible ChE inhibitors used as affinity chromatography ligand and eluant, respectively. Although similarity of the N-terminal amino acid sequence of the enzyme with an internal sequence of ChEs is weak, its catalytic activity towards thiocholine esters, and its affinity for positively charged ligands supports the contention that this enzyme may belong to the ChE family. However, we cannot rule out that the enzyme belongs to another structural family of proteins having cholinesterase-like properties. The reaction of the enzyme with organophosphates suggests that it is a serine esterase, and currently this enzyme may be termed as having a cholinesterase-like activity.
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Affiliation(s)
- D Rochu
- Centre de Recherches du Service de Santé des Armées, Unité d'Enzymologie, BP 87, 38702 La Tronche Cedex, France
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Goutet JM, Baudon JJ, Vazquez MP, Renault F, Charritat JL, Fontaine JL. La dyskinésie œsophagienne du syndrome de Pierre-Robin est-elle la conséquence de l'immaturité physiologique ou du reflux gastro-œsophagien ? Arch Pediatr 1998. [DOI: 10.1016/s0929-693x(97)86921-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The combined effects of pressure and temperature on the activity of butyrylcholinesterase (BuChE) were investigated in the pressure range from 10(-3) to 5 kbar and temperature range from -10 degrees C to 70 degrees C. Inactivation of the enzyme showed a complex dependence on pressure and temperature. Under moderate pressures (1-3 kbar) at temperatures 40-65 degrees C BuChE was resistant to heat inactivation; under other conditions of pressure and temperature, the action of both parameters was synergistic and caused inactivation. Results allowed to construct a pressure-temperature kinetic phase diagram for the enzyme inactivation. The elliptic diagram for the irreversible transition active-->inactive BuChE as a function of both pressure and temperature has a positive angular coefficient. This indicates that pressure acts as a stabilizer of BuChE against heat denaturation.
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Affiliation(s)
- A Weingand-Ziadé
- Centre de Recherches du Service de Santé des Armées, Unité de Biochimie, La Tronche, France
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Noseda G, Harpey JP, Brandel JP, Roy C, Caille B, Prudent M, Maillard L, Renault F, Leveau J, Malafosse M. [Acute basal ganglia necrosis with favorable course during Mycoplasma encepahlitis]. Arch Pediatr 1996; 3:1107-10. [PMID: 8952776 DOI: 10.1016/s0929-693x(96)89518-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Acute bilateral striatal necrosis complicating the course of a post-infectious encephalitis is rare. CASE REPORT A previously healthy 5-year-old boy presented with an atypical pneumonia; he rapidly developed, encephalitis revealed by a generalized status epilepticus. After transient improvement, he became confused and mutic, with dystonic postures of his limbs. Painful stimulation resulted in prolonged facial grimacing and doleful cry. CT scan and MRI showed abnormal signals in the whole basal ganglia, typical of bilateral striatal necrosis. Serologic tests for Mycoplasma pneumoniae were positive. The child recovered almost completely. CONCLUSION A parainfectious process is probably responsible for the transient bilateral striatal necrosis seen in this patient who had Mycoplasma pneumoniae infection several days before the onset of neurologic symptoms. MRI seemed more reliable than CT-scan for the diagnosis of this condition.
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Affiliation(s)
- G Noseda
- Service de pédiatrie, hôpital de La Salpêtrière, Paris, France
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Flores-Guevara R, Renault F, Ostré C, Richard P. Maturation of the electroretinogram in children: stability of the amplitude ratio a/b. Electroencephalogr Clin Neurophysiol 1996; 100:422-7. [PMID: 8893659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We report the method and results of mesopic electroretinogram (ERG) recording by corneal electrode in 75 children aged from 0 to 15 years. This method gives an overall evaluation of the electrical activity of the retina in a rapid and acceptable manner, in the awake state and without sedation. The a- and b-waves were present at birth. The amplitude of these waves increased considerably throughout the period studied. The decrease in latencies was statistically significant only for the b-wave between birth and 6 months. The presence of oscillatory potentials increased with age. The amplitude ratio a/b remained constant at about 0.25 in all age groups. This a/b ratio thus constitutes, under the recording conditions described, a criterion of normality that is independent of age.
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Affiliation(s)
- R Flores-Guevara
- Laboratoire de Neurophysiologie Clinique de I'Enfant, Hôpital Armand-Trousseau, Paris, France
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