The properties and isolation of a myosin heavy chain degradation inhibitorin the sarcoplasmic protein of fish meat

A myosin heavy chain degradation inhibitor (MDI) prepared from the sarcopla smic protein of a particular fish meat inhibited the serine protease (tryps in, chymotrypsin) activity. The degradation of myosin heavy chain in the wa shed meat around 40 degrees C was also restrained by adding serine protease inhibitors. It is therefore conceivable that MDI is water soluble and acts as an inhibitor against serine protease in washed meat. MDI was isolated from the water soluble fraction of fish meat through a 4-s tep process, batch type DEAE ion exchange, ammonium sulfate fractionation, DEAE ionexchange chromatography, and Sephacryl S-300 gel filtration chromat ography. It was found to be a monomeric protein with a molecular weight of 80,000.