Identification and characterization of trypsin, chymotrypsin and elastase inhibitors in the hedgehog, Erinaceus europaeus, and their immunological relationships to those of other mammals (rat, pig and human).

1. Hedgehog plasma was separated by gel filtration on Sephacryl S-200, the fractions resolved by electrophoresis and the electrophoregrams characterized for trypsin, chymotrypsin and elastase inhibiting activities with both low and high molecular weight substrates. Approximate molecular weights were also determined. 2. At least ten protease inhibitors were characterized in hedgehog plasma including three macroglobulins. 3. The hedgehog protease inhibitors were identified by immunoelectrophoresis. Four protease inhibitors showed homologies with specific human, rat or swine antisera. These were alpha 2-and beta-macroglobulins, alpha 1-protease inhibitor, and alpha 2-antithrombin.