Peptides and genes coding for scorpion toxins that affect ion-channels.

Détails

ID Serval
serval:BIB_DEE203D02C80
Type
Article: article d'un périodique ou d'un magazine.
Sous-type
Synthèse (review): revue aussi complète que possible des connaissances sur un sujet, rédigée à partir de l'analyse exhaustive des travaux publiés.
Collection
Publications
Titre
Peptides and genes coding for scorpion toxins that affect ion-channels.
Périodique
Biochimie
Auteur(s)
Possani L.D., Merino E., Corona M., Bolivar F., Becerril B.
ISSN
0300-9084
Statut éditorial
Publié
Date de publication
2000
Peer-reviewed
Oui
Volume
82
Numéro
9-10
Pages
861-868
Langue
anglais
Résumé
Most scorpion toxins are ligand peptides that recognize and bind to integral membrane proteins known as ion-channels. To date there are at least 202 distinct sequences described, obtained from 30 different species of scorpions, 27 from the family Buthidae and three from the family Scorpionidae. Toxins that recognize potassium and chloride channels are usually from 29 to 41 amino acids long, stabilized by three or four disulfide bridges, whereas those that recognize sodium channels are longer, 60 to 76 amino acid residues, compacted by four disulfide bridges. Toxins specific for calcium channels are scarcely known and have variable amino acid lengths. The entire repertoire of toxins, independently of their specificity, was analyzed together by computational programs and a phylogenetic tree was built showing two separate branches. The K(+) and Cl(-) channel specific toxins are clustered into 14 subfamilies, whereas those of Na(+) and Ca(2+) specific toxins comprise at least 12 subfamilies. There are clear similarities among them, both in terms of primary sequence and the main three-dimensional folding pattern. A dense core formed by a short alpha helix segment and several antiparallel beta-sheet stretches, maintained by disulfide pairing, seems to be a common structural feature present in all toxins. The physiological function of these peptides is manifested by a blockage of ion passage through the channels or by a modification of the gating mechanism that controls opening and closing of the ion pore.
Mots-clé
Amino Acid Sequence, Animals, Ion Channels/drug effects, Molecular Sequence Data, Peptides/chemistry, Peptides/genetics, Phylogeny, Protein Folding, Protein Structure, Secondary, Protein Structure, Tertiary, Scorpion Venoms/chemistry, Scorpion Venoms/genetics, Sequence Homology, Amino Acid
Pubmed
Web of science
Création de la notice
10/03/2008 11:54
Dernière modification de la notice
20/08/2019 16:03
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