Dystrophin in Electric Organ of Torpedo californica Homologous to That in Human Muscle

We have found that dystrophin is highly concentrated at neuromuscular junctions and innervated membranes of the electric organ of Torpedo californica. In acetylcholine receptor-rich Torpedo membrane preparations dystrophin represents approximately 0.4% of total protein and can be extracted from these membranes by alkaline treatment in the absence of detergent, indicating that it is a peripheral membrane protein. Polyclonal antibodies raised against electrophoretically isolated Torpedo dystrophin cross-react with dystrophin in human muscle and unequivocally discriminate between normal and Duchenne muscular dystrophy patient's muscle. These results indicate that dystrophin is phylogenetically a highly conserved protein and that the relatively abundant dystrophin in electric organ would facilitate further investigations of its structure and function.