Characterization and partial purification from pheochromocytoma cells of an endogenous equivalent of scyllatoxin, a scorpion toxin which blocks small conductance Ca(2+)-activated K+ channels.

Abstract

This work describes the partial purification of a heat-stable peptide which has the same properties as the scorpion toxin, scyllatoxin, a specific blocker of one class of Ca(2+)-activated K+ channels: (i) it competes with [125I]apamin for binding to the same site, (ii) like apamin and scyllatoxin, it blocks the after-potential hyperpolarization in skeletal muscle cells in culture, (iii) like apamin and scyllatoxin, it contracts guinea-pig taenia coli relaxed by epinephrine, (iv) it cross-reacts with antibodies raised against scyllatoxin but not with antibodies raised against apamin.

• Authors: P Auguste, M Hugues, M Borsotto, J Thibault, G Romey, T Coppola, M Lazdunski
• Journal: Brain research (Brain Res) Vol. 599 Issue 2 Pg. 230-6 (Dec 25 1992) ISSN: 0006-8993 [Print] Netherlands
• PMID: 1337858 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Potassium Channels
• Receptors, Neurotransmitter
• Scorpion Venoms
• apamin receptor
• leiurotoxin I
• Apamin
• Endopeptidases
• Calcium

Topics

• Animals
• Antibody Specificity (immunology)
• Apamin (antagonists & inhibitors, metabolism)
• Binding, Competitive (physiology)
• Calcium (physiology)
• Electric Conductivity
• Endopeptidases
• Hot Temperature
• PC12 Cells
• Potassium Channels (drug effects)
• Radioimmunoassay
• Receptors, Neurotransmitter (metabolism)
• Scorpion Venoms (immunology, isolation & purification, pharmacology)