Alpha 1-antitrypsin and alpha 2-macroglobulin do not inhibit the kinin-releasing activity of kallikreins from human urine and saliva.

Alpha 1-Antitrypsin, alpha 2-macroglobulin and low-molecular weight kininogen were isolated from human serum and kallikreins from human urine and saliva. Alpha 1-antitrypsin and alpha 2-macroglobulin inhibited the activity of trypsin in releasing kinin from low-molecular weight kininogen, due to their binding with the enzyme, but did not inhibit or bind with urinary and salivary kallikreins.