1. Functional expression and purification of recombinant Tx1, a sodium channel blocker neurotoxin from the venom of the Brazilian "armed" spider, Phoneutria nigriventer.
- Author
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Diniz MR, Theakston RD, Crampton JM, Nascimento Cordeiro Md, Pimenta AM, De Lima ME, and Diniz CR
- Subjects
- Amino Acid Sequence, Animals, Binding, Competitive drug effects, Brazil, CHO Cells, Cloning, Molecular, Cricetinae, Injections, Intraventricular, Mice, Molecular Sequence Data, Neuropeptides biosynthesis, Neuropeptides toxicity, Protein Binding, Rats, Rats, Wistar, Recombinant Proteins biosynthesis, Recombinant Proteins isolation & purification, Recombinant Proteins toxicity, Sodium metabolism, Sodium Channel Blockers metabolism, Sodium Channel Blockers toxicity, Sodium Channels metabolism, Species Specificity, Spider Venoms chemistry, Structure-Activity Relationship, Neuropeptides isolation & purification, Sodium Channel Blockers isolation & purification, Sodium Channels drug effects, Spider Venoms genetics, Spiders genetics
- Abstract
Tx1 from the venom of the Brazilian spider, Phoneutria nigriventer, is a lethal neurotoxic polypeptide of M(r) 8600 Da with 14 cysteine residues. It is a novel sodium channel blocker which reversibly inhibits sodium currents in CHO cells expressing recombinant sodium (Nav1.2) channels. We cloned and expressed the Tx1 toxin as a thioredoxin fusion product in the cytoplasm of Escherichia coli. After semipurification by immobilized Ni-ion affinity chromatography, the recombinant Tx1 was purified by reverse phase chromatography and characterized. It displayed similar biochemical and pharmacological properties to the native toxin, and it should be useful for further investigation of structure-function relationship of Na channels.
- Published
- 2006
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