Mathematical models for combined high pressure and thermal plasmin inactivation kinetics in two model systems.

The combined high-pressure thermal inactivation kinetics of plasmin was studied in 2 model systems. The first system contained both plasmin and plasminogen, whereas, in the second system, all plasminogen was converted into plasmin, with urokinase, before the inactivation studies. High-pressure treatments were conducted in the range of 300 to 800 MPa combined with temperatures from 30 to 65 degrees C. Under all conditions of pressure and temperature (isobaric-isothermal) studied, for both systems, first-order inactivation was observed. A third-degree polynomial model (derived from thermodynamic principles) successfully described the temperature and pressure dependence of the inactivation rate constant over the entire experimental domain. The antagonistic effect and the stabilization effect observed above a threshold pressure value of 600 MPa were thought to be related to the disruption of disulfide bonds in plasmin and plasminogen.