title: Studies on the influence of Trasylol on the partition of trypsin between the human plasma protease inhibitors in vitro.
abstract: The distribution of trypsin between the protease inhibitors of human serum with and without Trasylol was studied in vitro. 1) Trypsin was preferentially bound by alpha2-macroglobulin on addition of small amounts of the enzyme to normal serum in both the presence and absence of Trasylol in a molar concentration equal to that of alpha2-macroglobulin. 2) On saturation of alpha2-macroglobulin, a considerable amount of trypsin was bound by Trasylol even when most of the serum alpha1-antitrypsin was in a free form. 3) In reaction mixtures containing small amounts of trypsin, Trasylol was identified in a free form as well as in complex with trypsin-alpha2-macroglobulin complex and to a limited extent with trypsin. 4) With larger amounts of trypsin, sufficient to saturate alpha2-macroglobulin, increasing amounts of Trasylol were bound to trypsin. The relative amount of Trasylol bound to trypsin-alpha2-macroglobulin complexes was now smaller. This was explained by a higher affinity (or binding rate) of Trasylol for trypsin than for trypsin-alpha2-macroglobulin complexes. 5) Trypsin-Trasylol complexes showed no signs of dissociation after 5 h incubation at 37 degrees C in serum.
mesh_terms: D007611:Aprotinin; D001798:Blood Proteins; D006801:Humans; D007122:Immunoelectrophoresis; D011480:Protease Inhibitors; D014357:Trypsin; D014361:Trypsin Inhibitors / Q000097:blood
chemical_list: D001798:Blood Proteins; D011480:Protease Inhibitors; D014361:Trypsin Inhibitors; D007611:Aprotinin; D014357:Trypsin