That's the current theory. Research in the past seven years has identified eleven molecules that seem to be related to the calpain family. None of these newly identified molecules has been characterized scientifically. Although the gene has been identified, the protein has not been obtained despite efforts by Goll and his laboratory and a number of laboratories around the world. Goll says there's enough calpain in muscle tissue to destroy it in ten minutes, yet this doesn't happen, so it seems that only one or two percent of the calpain in muscle is active at any one time and that something is keeping the rest of it turned off.
Scientists believe that's what calpastatin does.
When it's absent or its action is repressed, calpains in muscles go wild. In growth, it's not how fast muscle tissue is formed, but the rate of breakdown that frequently determines whether animals grow and how fast they grow, according to Goll. In animal agriculture, the calpain system also affects the quality of the meat. Although animals can grow faster without degrading proteins in their systems, such circumstances may also result in tougher meat. Goll believes it will be possible to develop products to enhance the rate and efficiency with which domestic animals deposit edible skeletal muscle.