Properties of ω conotoxin MVIIC receptors associated with α1A calcium channel subunits in rat brain

Abstract
Solubilized 125I‐ω conotoxin MVIIC receptors from rat cerebellum were immunoprecipitated by antibodies directed against the calcium channel α1A subunit. Anti‐αIA antibodies recognized a 240‐220, 180 and 160 kDa proteins in immunoblots of cerebellar membranes. Disuccinimidyl suberate cross‐linked 125I‐ω conotoxin MVIIC to an α2δ‐like 200‐180 kDa subunit, which migrated at 150‐140 kDa after disulfide reduction. These observations are consistent with a heteromeric structure in which high affinity ω conotoxin MVIIC binding sites formed by α1A subunits are located in close proximity to peripheral α2 subunits.