Identification of troponin-I of crayfish myofibrils

Crayfish (Procambarus clarkii) myofibrils contain two basic proteins of molecular weights of 25,000 and 23,000. Both of the two proteins inhibit actomyosin ATPase as the vertebrate troponin-I does. These results differ from the previous one that troponin-I of crayfish (Astacus leptodactylus) showed a single band on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE).