Serpin

Serine protease inhibitors or serpins (short for serine protease inhibitor) are a group of proteins that inhibit peptidases (old name: proteases). Serine proteases are defined by the presence of a serine residue in their active domain. Serpins have in common that they inhibit this group of enzymes. They are part of the larger group of protease inhibitors. Although the function of serpins varies widely, they share a number of structural details. Additionally, pathological forms can occasionally inhibit the wrong serine protease.

Proteins in the serpin class:

• Alpha 1-antitrypsin (the most important serpin, often simply referred to as protease inhibitor);
• Alpha 1-antichymotrypsin;
• Antithrombin (coagulation);
• Complement 1-inhibitor;
• Neuroserpin (recently discovered);
• Plasminogen activator inhibitor 1 (coagulation, fibrinolysis);