Calmodulin-binding profiles for nebulin and dystrophin in human skeletal muscle

Nebulin and dystrophin are two high-molecular-mass skeletal muscle proteins that have both been associated with the defective gene in Duchenne muscular dystrophy, although the function of neither protein is known. Other high-molecular-mass, calmodulin-binding proteins have recently been implicated in regulating calcium release from skeletal muscle. Western blots of human skeletal muscle biopsy samples were probed with biotinylated calmodulin; nebulin was identified as a prominent high-molecular-mass calmodulin-binding protein but dystrophin did not bind detectable amounts of biotinylated calmodulin. Dystrophin was absent in a Duchenne muscle biopsy.