PT  - JOURNAL ARTICLE
AU  - WILLIAM A. CATTERALL
AU  - MARTIN RISK
TI  - Toxin T<sub>4<sub>46</sub></sub> from <em>Ptychodiscus brevis</em> (Formerly <em>Gymnodinium breve</em>) Enhances Activation of Voltage-Sensitive Sodium Channels by Veratridine
DP  - 1981 Mar 01
TA  - Molecular Pharmacology
PG  - 345--348
VI  - 19
IP  - 2
4099  - http://molpharm.aspetjournals.org/content/19/2/345.short
4100  - http://molpharm.aspetjournals.org/content/19/2/345.full
SO  - Mol Pharmacol1981 Mar 01; 19
AB  - Ptychodiscus brevis toxin T446 markedly enhances persistent activation of voltage-sensitive sodium channels in neuroblastoma cells by veratridine. Half-maximal enhancement is observed at 50 ng of T446 per milliliter. At maximally effective concentrations, T446 has no effect on specific binding of 125I-labeled scorpion toxin and slightly enhances specific binding of [3H]saxitoxin. Thus, T446 enhances veratridine action but does not bind to any of the three neurotoxin receptor sites on the sodium channels that have been previously described. T446 may act at a new toxin-receptor site associated with voltage-sensitive sodium channels. ACKNOWLEDGMENTS We thank Ms. Cynthia S. Morrow and Ms. Sherryann C. Pesheck for excellent technical assistance.