Biochemical characterisation of chymotrypsin from the midgut gland of yellowleg shrimp, Penaeus californiensis

•A chymotrypsin with collagenolytic activity from Penaeus californiensis is described.•The shrimp chymotrypsin is extensively compared to bovine chymotrypsin.•It is resistant to SDS and its mature protein consists of only one polypeptide chain.•Chymotrypsin is stable to temperature (50°C), sensible to low pH, possess acidic pI. Chymotrypsin from shrimp, Penaeus californiensis, was compared to Bos taurus chymotrypsin, and its structure–function relationship was studied. Catalytic efficiency toward synthetic substrate is lower, but it has a broad specificity and higher activity toward protein substrates, including collagen. It is active at pH 4–10 and fully active up to 50°C for 2h and at least nine days at room temperature. The activation peptide is twice as long as bovine chymotrypsinogen, has less disulfide bridges, and is a single polypeptide. Only one activation step is necessary from chymotrypsinogen to the mature enzyme. Postmortem implications in muscle softening and melanisation, resistance to temperature and pH and efficiency with proteinaceous substrates make chymotrypsin useful as a biotechnological tool in food processing. This makes shrimp processing wastes useful as a material for production of fine reagents.