Fibrinogenolytic Demonstration of Activation and Inhibition of Tryptase in Plasma Protein Fraction-I ("Antihemophilic Globulin").

Abstract

A fibrinogenolytic (rather than fibrinolytic) technic serves to show natural plasma protease (tryptase) and its precursor (tryptogen) in a variety of plasma fractions. Streptokinase ("streptococcal fibrinolysin") is a suitable activator of tryptogen. Bovine plasma Fraction I and fibrinogen lack both active tryptase and tryptogen and do not contain significant amts. of tryptase-inhibitor. The existence of tryptogen, together with a trace of tryptase in normal human plasma Fraction I (and fibrinogen), may be significant in connection with use as "antihemophilic globulin". Heparin, unaided, shows no enzyme-inhibitory effects. Antitryptase actions of (a) crystalline trypsin-inhibitors from pancreas and soybean and (b) crude fractionated egg-albumen, favor the characterization of the plasma protease as a "tryptase".