Comparison of the reactions of neutral granulocyte proteases with the major plasma protease inhibitors and with antiplasmin.

Reaction mixtures of human serum and increasing amounts of granulocyte collagenase, elastase and chymotrypsin-like enzyme were studied by crossed immunoelectrophoresis utilizing antibodies against alpha1-antitrypsin, alpha1-antichymotrypsin, and antiplasmin. The increasing complex formation of alpha1-antitrypsin and alpha 1-antichymotrypsin with the different granulocyte proteases was not accompanied by any changes in the electrophoretic mobility or precipitate pattern of antiplasmin until the protease binding capacity of serum was saturated. The antiplasmin component in the reaction mixtures of human serum and granulocyte collagenase or elastase was not precipitated by antibodies against the proteases. The results indicate that none of the granulocyte proteases are bound by antiplasmin and that these enzymes do not activate plasminogen in serum.