| Popis: |
Human lung cells in primary culture and serial subculture were used to study the production of inhibitory activity and to isolate and identify inhibitor(s) of trypsin and plasmin produced and released by the cells into the supernatant medium. Assays of inhibitory activity were performed on fibrin, and casein substrate and results expressed in BAEE units of trypsin inhibited on the former substrate. Inhibitory activity against plasmin and trypsin accumulated progressively in serum free supernates of cultures to concentrations of 80–150 BAEE units/ml and was isolated from the supernates by concentration with Amicon PM 30 membranes, gel filtration on Sephadex G—100 or G-200 columns and polyacrilamide gel electrophoresis. On calibrated columns inhibitory activity eluted in the range of 75,000 mol wt substances. On immunodiffusion, performed using a wide range of concentrations of chromatographed inhibitor preparations with specific activity of about 1,300 BAEE units/mg protein there was no cross-reaction with antiserum to a1-antitrypsin, a2-macroglobulin, C1-esterase inhibitor or inter-a-trypsin inhibitor. There was also no cross-reaction with antiserum to antithrombin III or antichymotrypsin. Immunoelectrophoresis showed no immunoreactive material with the antisera. These observation indicate the production in lung of inhibitor(s) differing from the major protease inhibitors and derivatives or subunits of these inhibitors described to date. |
