Biochemical characterization of insect neuronal sodium channels

✍ Scribed by Dalia Gordon; Haim Moskowitz; Eliahu Zlotkin

• Book ID: 102748277
• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 766 KB
• Volume: 22
• Category: Article
• ISSN: 0739-4462
• DOI: 10.1002/arch.940220106

✦ Synopsis

The pharmacological uniqueness of the insect sodium channels i s indicated by their ability to bind the excitatory and depressant insect selective neurotoxins derived from scorpion venom. The latter were shown to bind and modify sodium conductance exclusively in insect neuronal membranes. The insect sodium channel polypeptides were identified by immunoprecipitation using site-directed antibody, anti SP19 (corresponding to a highly conserved segment in the sodium channel a subunits), followed by radiophosphorylation and SDS-PAGE autoradiography. Sodium channel polypeptide in the central nervous system (CNS) of insects belonging to four distinct orders (Orthoptera, Dyctioptera, Diptera, and Lepidoptera) were shown to (1) serve as substrates for phosphorylation by CAMP-dependent protein kinase; (2) be devoid of disulfide linkage to smaller subunits unlike sodium channels i n vertebrate

CNS;

(3) be glycoproteins as demonstrated by endoglycosidase F treatment '