Some kinetic properties of dogfish chymotrypsin.

A comparison of some kinetic properties was made between bovine chymotrypsin and chymotrypsin isolated from the spiny dogfish (Squalus acanthias). The major difference between the two enzymes was observed in the molecular activity (kcat), with the dogfish enzyme being two to three times more active than the bovine enzyme. The exact difference was dependent on the substrate and assay conditions. The two enzymes showed similar kinetic properties with respect to the following: similar inhibition by indole and naphthol derivatives, activities vs BTEE and a series of n-fatty acid esters of p-nitrophenol, KM values, optimal pH and temperature and activation energies.