Atrotoxin: A specific agonist for calcium currents in heart

Susan L. Hamilton, Atsuko Yatani, Mary Jane Hawkes, Kevin Edward Redding, Arthur M. Brown

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

A specific label for voltage-dependent calcium channels is essential for the isolation and purification of the membrane protein that constitutes the calcium channel and for a better understanding of its function. A fraction of Crotalus atrox that increases voltage-dependent calcium currents in single, dispersed guinea pig ventricular cells was isolated. In the doses used, neither sodium nor potassium currents were changed. The fraction was active in the absence of detectable phospholipase or protease activity, and the active component, designated atrotoxin, produced its effect rapidly and reversibly. The effect was produced by extracellular but not intracellular application of the agent. The increase in Ca2+ current was blocked by the Ca 2+ channel blockers cobalt and nitrendipine. The active fraction completely blocked specific [3H]nitrendipine binding to guinea pig ventricular membrane preparations. The inhibition of nitrendipine binding by atrotoxin was apparently via an allosteric mechanism. Thus atrotoxin was shown to bind to the Ca2+ channel and to act as a specific Ca2+ channel agonist.

Original languageEnglish
Pages (from-to)182-184
Number of pages3
JournalScience
Volume229
Issue number4709
Publication statusPublished - 1985

    Fingerprint

ASJC Scopus subject areas

  • General

Cite this

Hamilton, S. L., Yatani, A., Hawkes, M. J., Redding, K. E., & Brown, A. M. (1985). Atrotoxin: A specific agonist for calcium currents in heart. Science, 229(4709), 182-184.