Photoaffinity Labeling of the Electroplax Sodium Channel with a Photoreactive μ-Conotoxin Carrying a Radioactive and Chromogenic Diazirine

Abstract

Photoreactive derivatives of μ-conotoxin GIIIA carrying a radioactive and chromogenic diazirine have been prepared as a photoaffinity labeling reagent for muscle-type sodium channels. When the reagent was photolyzed in the presence of the eel sodium channel, radioactivity was specifically incorporated into the channel protein.