Interaction of polypeptide neurotoxins with a receptor site associated with voltage-sensitive sodium channels

✍ Scribed by Catterall, William A. ;Beneski, Daniel A.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1980
• Tongue: English
• Weight: 550 KB
• Volume: 14
• Category: Article
• ISSN: 0091-7419
• DOI: 10.1002/jss.400140304

✦ Synopsis

Abstract

Anthopleurin A, a polypeptide toxin from the Pacific sea anemone Anthopleura xanthogrammica, enhances persistent activation of voltage‐senstive sodium channels by the alkaloid toxins veratridine and batrachotoxin with K~0.5~ = 20 nM. This effect is inhibited by depolarization. There is a close correlation between enhancement of sodium channel activation and block of [^125^I] scorpion toxin binding by unlabeled scorpion toxin, sea anemone toxin II from Anemonia sulcata, and Anthopleurin A, indicating that these three polypetide toxins interact with a common receptor site in modifying sodium channel function. Photoactivable derivatives of scorpion toxin label a single M~r~ ∼ 250,000 polypeptide chain at the polypeptide toxin receptor site. Labeling is blocked by unlabeled scorpion toxin or depolarization and is not observed in variant neuroblastoma clones, which lack sodium channels. These results identify a protein component of the polypeptide toxin receptor site of voltage‐sensitive sodium channels.