Elapidae Toxins: The Fasciculins, and their Interaction with Acetylcholinesterase

Marchot, P.; Bougis, Pierre E.

doi:10.1007/978-3-0348-8466-2_16

Cited by 3 publications

(5 citation statements)

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“…The short α‐neurotoxin NmmI was purified from the venom of Naja mossambica mossambica (Marchot et al , 1988). The long α‐neurotoxins Cbtx ( N. naja siamensis toxin 3) (Latoxan, France) and Bgtx (Sigma‐Aldrich) were analyzed by native‐PAGE with migration toward the cathode and SDS–PAGE (20% homogenous gels) (Marchot and Bougis, 2000), and by mass spectrometry. They were further purified using reverse‐phase HPLC on ultrasphere‐octyl and an acetonitrile gradient in 0.1% TFA (Marchot and Bougis, 2000).…”

Section: Methodsmentioning

confidence: 99%

“…The long α‐neurotoxins Cbtx ( N. naja siamensis toxin 3) (Latoxan, France) and Bgtx (Sigma‐Aldrich) were analyzed by native‐PAGE with migration toward the cathode and SDS–PAGE (20% homogenous gels) (Marchot and Bougis, 2000), and by mass spectrometry. They were further purified using reverse‐phase HPLC on ultrasphere‐octyl and an acetonitrile gradient in 0.1% TFA (Marchot and Bougis, 2000). Fractional occupancies of the five AChBP subunit interfaces and final stoichiometry of toxin binding were analyzed by using increasing toxin‐to‐pentamer molar ratios (2 h incubation; room temperature) and native‐PAGE (12.5% homogenous gels) (Marchot et al , 1996) (Figure 2).…”

Section: Methodsmentioning

confidence: 99%

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Crystal structure of a Cbtx–AChBP complex reveals essential interactions between snake α-neurotoxins and nicotinic receptors

Bourne

Talley

Hansen

et al. 2005

EMBO J

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298

285

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The crystal structure of the snake long alpha-neurotoxin, alpha-cobratoxin, bound to the pentameric acetylcholine-binding protein (AChBP) from Lymnaea stagnalis, was solved from good quality density maps despite a 4.2 A overall resolution. The structure unambiguously reveals the positions and orientations of all five three-fingered toxin molecules inserted at the AChBP subunit interfaces and the conformational changes associated with toxin binding. AChBP loops C and F that border the ligand-binding pocket move markedly from their original positions to wrap around the tips of the toxin first and second fingers and part of its C-terminus, while rearrangements also occur in the toxin fingers. At the interface of the complex, major interactions involve aromatic and aliphatic side chains within the AChBP binding pocket and, at the buried tip of the toxin second finger, conserved Phe and Arg residues that partially mimic a bound agonist molecule. Hence this structure, in revealing a distinctive and unpredicted conformation of the toxin-bound AChBP molecule, provides a lead template resembling a resting state conformation of the nicotinic receptor and for understanding selectivity of curaremimetic alpha-neurotoxins for the various receptor species.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Crystal structure of a Cbtx–AChBP complex reveals essential interactions between snake α-neurotoxins and nicotinic receptors

Bourne

Talley

Hansen

et al. 2005

EMBO J

Self Cite

298

285

View full text Add to dashboard Cite

show abstract

“…The long a-neurotoxins Cbtx (N. naja siamensis toxin 3) (Latoxan, France) and Bgtx (Sigma-Aldrich) were analyzed by native-PAGE with migration toward the cathode and SDS-PAGE (20% homogenous gels) (Marchot and Bougis, 2000), and by mass spectrometry. They were further purified using reverse-phase HPLC on ultrasphere-octyl and an acetonitrile gradient in 0.1% TFA (Marchot and Bougis, 2000). Fractional occupancies of the five AChBP subunit interfaces and final stoichiometry of toxin binding were analyzed by using increasing toxin-to-pentamer molar ratios (2 h incubation; room temperature) and native-PAGE (12.5% homogenous gels) (Figure 2).…”

Section: Preparation and Analysis Of The Cbtx-achbp Complexmentioning

confidence: 99%

Crystal structure of a Cbtx–AChBP complex reveals essential interactions between snake α-neurotoxins and nicotinic receptors

Bourne¹,

Talley²,

Hansen³

et al. 2006

EMBO J

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“…Les fasciculines, petites protéines (7 kDa) isolées des venins de serpent mamba, sont les seuls inhibiteurs pep tidiques connus de l'AChE (6,7). Elles appartiennent à la famille structurale des toxines « à trois doigts » (boucles I, II, III) (8,9), laquelle comprend également les a-et K-neurotoxines, bloquants spécifiques des récep teurs nicotiniques à l'acétylcholine des systèmes nerveux périphérique et central; les toxines «muscariniques», agonistes spécifiques de certains sous-types du récepteur muscarinique ; la calciseptine et la toxine FS2, bloquants spécifiques des canaux calciques de type L ; la dendroaspine (ou mambine), inhibiteur de l'agrégation pla quettaire et antagoniste du complexe GPIIb-IIIa possé dant un motif RGD; les cardiotoxines, interagissant avec les lipides membranaires (10).…”

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“…Les fasciculines inhibent sélectivement les AChEs de mammifères et de poissons électriques avec des valeurs de Ki pico-à nanomolaires (6,7). Des études cinétiques ou menées à l'équilibre ont montré que le complexe fasciculine-AChE, malgré sa grande affinité et sa faible vitesse de dissociation, conserve une légère activité cata lytique résiduelle ; de même, certains inhibiteurs spéci fiques du site catalytique peuvent toujours atteindre le site actif de l'enzyme complexée à la fasciculine (11)(12)(13)(14)(15)(16).…”

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L’interaction fasciculine-acétylcholinestérase

Marchot¹

1999

J. Soc. Biol.

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Reçu le 9 novembre 1999 RÉSUMÉ L'acétylcholinestérase (AChE) est une enzyme-clé du mécanisme de transmission cholinergique. Les fasciculines, petites protéines « à trois doigts » isolées des venins de serpent mamba, sont des inhibiteurs puis sants et sélectifs des AChEs de mammifères et pois sons électriques. L'interaction fasciculine-AChE constitue un exemple parfait d'interaction entre une toxine animale et son récepteur macromoléculaire. En effet, par leur sélectivité, leur remarquable affi nité, leur caractère d'inhibiteur allostérique, et leur nature protéique (donc accessible à la chimie des pro téines et la biologie moléculaire), les fasciculines constituent des outils de choix, « scalpels molécu laires » pour l'étude de l'AChE. Les travaux présen tés dans ce chapitre ont été menés selon une approche multidisciplinaire faisant intervenir des techniques distinctes, mais complémentaires, ainsi que de nom breuses collaborations. Les résultats obtenus contri buent à la définition des bases structurales et dyna miques non seulement des mécanismes d'inhibition de l'AChE par les fasciculines, mais également de la fonctionnalité du site périphérique de l'AChE, site distinct du site catalytique et doué de propriétés régu latrices. SUMMARY (The fasciculin-acetylcholinesterase interaction)Acetylcholinesterase (AChE) terminates the action of the neurotransmitter acetylcholine at cholinergic synapses in the central and peripheral nervous sys tems. Fasciculins, which belong to the family of "three-fingered" snake toxins, selectively inhibit mammalian AChEs with Ki values in the picomolar range. In solution, the cationic fasciculin appears to bind to the enzyme's peripheral anionic site, located near the mouth of the gorge leading to the active cen ter, to inhibit catalysis either allosterically or by crea ting an electrostatic barrier at the gorge entry (or both). Yet the crystal structure of the fasciculin-mouse AChE complex, which shows that the central loop of fasciculin fits snugly at the entrance of the gorge, sug gests that the mode of action of fasciculin is steric occlusion of substrate access to the active center. Mutagenesis of the fasciculin molecule, undertaken to establish a functional map of the binding surfaces, identified determinants common to those identified by

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Elapidae Toxins: The Fasciculins, and their Interaction with Acetylcholinesterase

Cited by 3 publications

References 52 publications

Crystal structure of a Cbtx–AChBP complex reveals essential interactions between snake α-neurotoxins and nicotinic receptors

Crystal structure of a Cbtx–AChBP complex reveals essential interactions between snake α-neurotoxins and nicotinic receptors

Crystal structure of a Cbtx–AChBP complex reveals essential interactions between snake α-neurotoxins and nicotinic receptors

L’interaction fasciculine-acétylcholinestérase

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