A short-chain peptide toxin isolated from Centruroides sculpturatus scorpion venom inhibits ether-à-go-go-related gene K(+) channels.
From the venom of the American scorpion Centruroides sculpturatus Ewing we have isolated a minute peptide fraction (named CsEKerg1) which reversibly inhibits the current through ERG (ether-à-go-go-related gene) K(+) channels. Isolation was done by CM-cellulose column chromatography and reversed phase high-performance liquid chromatography. To test for an effect on ERG channels we used NG108-15 neuroblastomaxglioma hybrid cells voltage-clamped in the whole-cell mode. CsEKerg1 contains 43 amino acids and has a molecular weight of 4833. Its amino acid sequence is similar but not identical to that of ergtoxin, a peptide isolated recently from the venom of the Mexican scorpion Centruroides noxius [FASEB J. 13 (1999) 953]. Half inhibition of ERG current occurs at a peptide concentration of 1.12microg/ml.
Nastainczyk
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Department of Biochemistry, University of Saarland, D-66421 Homburg-Saar, Germany.
Meves
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H
Watt
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D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D051638:Ether-A-Go-Go Potassium Channels; D005910:Glioma; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008969:Molecular Sequence Data; D009447:Neuroblastoma; D018408:Patch-Clamp Techniques; D026902:Potassium Channel Blockers / Q000302:isolation & purification / Q000494:pharmacology*; D015221:Potassium Channels / Q000235:genetics*; D024642:Potassium Channels, Voltage-Gated; D051381:Rats; D012604:Scorpion Venoms / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D012605:Scorpions / Q000502:physiology*; D020539:Sequence Analysis, Protein; D021241:Spectrometry, Mass, Electrospray Ionization; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000502:physiology
C470886:CsEKerg1, Centruroides sculpturatus; D051638:Ether-A-Go-Go Potassium Channels; C402401:Kcnh5 protein, rat; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D012604:Scorpion Venoms; C118951:ergotoxin, Centruroides noxius