Aprotinin belongs to the group of antifibrinolytics and is a protease inhibitor consisting of 58 amino acids, which is cross-linked as a single-chain polypeptide via 3 disulfide bridges. Aprotinin is mainly extracted from the bovine lung. Aprotinin is also available in recombinant form.
It is a non-specific protein that inhibits serine proteases, trypsin, kallikrein, plasmin and antitrypsin. In addition to the effects mentioned above, it inhibits the thrombolytic action of streptokinase, the tissue plasminogen activator (tPA) and urokinase.