A group of novel latent serine proteinases degrading myosin heavy chain in fish muscle.

Through a study on thermal degradation of fish jelly products, the existence of a group of latent trypsin-like serine proteinases was demonstrated in fish muscle. These proteinases share common properties in existing as latent forms (being activated by heating around neutral pH in the presence of NaCl), having trypsin-like serine proteinase properties and showing strong myosin heavy chain degrading activity. This group of proteinases could be classified into four subtypes according to the intracellular localization (sarcoplasmic and myofibril-associated types) and the optimum temperature range (50 and 60 degrees C types).