THE BIOLOGICAL SIGNIFICANCE AND CHEMISTRY OF A PROTEASE INHIBITOR NEWLY ISOLATED FORM ANIMAL TISSUES

摘要

A specific protease inhibitor of polypeptide nature is isolated from the healing Arthus skin site and highly purified as a fibrous substance by means of chromatography; it behaves as a homologous substance electrophoretically and in ultracentrifugation. Its iso electric point is around 6,6 and its sedimentation coefficient is 1.21 S. It inactivates the SH protease responsible for the Arthus skin lesion and papain, but has no effect on trypsin and chymotrypsin. Biological significance of the inhibitor is being studied. Anaphylactic release of two different permeability factors is found in cultured cells, in parallel with the morphological response, histamine being released before our new permeability factor. The release of histamine is possibly concerned with the intracellular SH protease which is inactivated by the above inhibitor. Such in vitro results are reproduced in the skin of sensitized rabbit. Soluble antigen-antibody complexes can release only histamine in vitro and in vivo, suggesting their different mechanisms in the cellular damage. Study of in vivo significance in suppressing the various types of inflammatory lesions is now in good progress.