Enzyme kinetics and characterization of mouse pancreatic elastase.

In the present study we have purified and characterized murine pancreatic elastase. The enzyme was extracted from acetone powders of mouse pancreas, fractionally precipitated with ammonium sulfate, and further purified by ion exchange chromatography to a single band on SDS-PAGE. The mouse enzyme exists in a proform, which was activated by removing a signal peptide by tryptic cleavage. The active form of mouse pancreatic elastase was shown by ultracentrifugation to have a molecular weight of 25.9 kDa and a frictional ratio of 1.26. The pH optimum for proteolytic activity was 8.0. Kinetic measurements were made with a variety of substrates and inhibitors and compared with elastases from other sources. The enzymatic properties and kinetic profiles for mouse pancreatic elastase were similar to other known serine elastases.