Maurotoxin, a four disulfide bridge toxin fromScorpio maurusvenom: purification, structure and action on potassium channels

Autor: R. Kharrat, Hervé Rochat, M. El Ayeb, Marcel Crest, J. Van Rietschoten, F. Sampieri, R. Oughideni, Marie-France Martin-Eauclaire, Pascal Mansuelle
Přispěvatelé: Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, Institut Pasteur de Tunis, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Biochimie - Ingénierie des protéines, Université de la Méditerranée - Aix-Marseille 2-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Neurobiologie (LNB), Centre National de la Recherche Scientifique (CNRS), This research was supported in part by funds from European Economic Community (Grant CI1-CT 93-0071), IFS attributed to R. Kharrat (Grant F/22 73-1), and PICS-CNRS 0916., We gratefully acknowledge Prof. K. Dellagi, Dr. H. Karoui, and Dr. I. Zenouaki for their constant encouragement and helpful advice. We would also like to thank Dr. Z. Ben Lasfar and his collaborators for providing Scorpio maurus venom. Dr. A. Van Dorsselaer from the Laboratoire de Spectrometrie de masse bio-organique (Strasbourg, France) is acknowledged for ESMS analyses.
Rok vydání: 1997
Předmět:
Magnetic Resonance Spectroscopy
Potassium Channels
Charybdotoxin
Protein Conformation
MESH: Potassium Channels/metabolism
MESH: Protein Structure
Secondary
Kaliotoxin
MESH: Amino Acid Sequence
Biochemistry
Protein Structure
Secondary
Mice
chemistry.chemical_compound
MESH: Protein Conformation
Structural Biology
MESH: Animals
Potassium channel
MESH: Scorpion Venoms/metabolism
Scorpion toxin
biology
MESH: Molecular Weight
[SDV.TOX]Life Sciences [q-bio]/Toxicology
MESH: Synaptosomes/metabolism
Cystine
MESH: Potassium Channels/drug effects
MESH: Rats
Stereochemistry
Molecular Sequence Data
Neurotoxins
MESH: Sequence Alignment
Biophysics
Scorpio maurus
Scorpion Venoms
Apamin
complex mixtures
MESH: Cystine/chemistry
Lethal Dose 50
Maurotoxin
Genetics
Animals
[SDV.BBM]Life Sciences [q-bio]/Biochemistry
Molecular Biology
Channel blocker
Amino Acid Sequence
MESH: Neurotoxins/isolation & purification
MESH: Mice
Molecular Biology
MESH: Molecular Sequence Data
MESH: Scorpion Venoms/pharmacology
MESH: Magnetic Resonance Spectroscopy
MESH: Apamin/metabolism
Cell Biology
MESH: Neurotoxins/metabolism
biology.organism_classification
Rats
MESH: Neurotoxins/chemistry
Molecular Weight
MESH: Lethal Dose 50
chemistry
MESH: Scorpion Venoms/chemistry
MESH: Neurotoxins/pharmacology
MESH: Scorpion Venoms/isolation & purification
Sequence Alignment
Synaptosomes
Zdroj: FEBS Letters
FEBS Letters, 1997, 406 (3), pp.284-290. ⟨10.1016/S0014-5793(97)00285-8⟩
ISSN: 0014-5793
1873-3468
DOI: 10.1016/s0014-5793(97)00285-8
Popis: International audience; A new toxin acting on K+ channels, maurotoxin (MTX), has been purified to homogeneity from the venom of the chactoid scorpion Scorpio maurus. MTX is a basic single chain 34 amino acid residue polypeptide, amidated at its C terminal, and crosslinked by four disulfide bridges. It shows 29-68% sequence identity with other K+ channel toxins, and presents an original disulfide pattern, the last two half-cystine residues (31-34) being connected. Although the first three disulfide bonds have not been defined experimentally, modelling based on the structure of charybdotoxin favored two combinations out of six, one of which has two bridges (3-24 and 9-29) in common with the general motif of scorpion toxins. The last bridge would connect residues 13 and 19. MTX inhibits the binding to rat brain synaptosomal membranes of both [125I]apamin, a SK(Ca) channel blocker (IC50 5 nM), and [125I]kaliotoxin, a Kv channel blocker (IC50 30 pM). MTX blocks the Kv1.1, Kv1.2 and Kv1.3 currents expressed in Xenopus oocytes with IC50 of 45, 0.8 and 180 nM, respectively. MTX represents a member of a new class of short toxins with 4 disulfide bridges, active on voltage-dependent K+ channel and also competing with apamin for binding to its receptor.
Databáze: OpenAIRE
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