Description_x000D_ Packaging_x000D_ 1 mg in glass bottle_x000D_ 25, 100 mg in poly bottle_x000D_ Application_x000D_ Aprotinin is largely used as an inhibitor of trypsin._x000D_ Biochem/physiol Actions_x000D_ Aprotinin is a competitive serine protease inhibitor that forms stable complexes with and blocks the active sites of enzyme. This binding is reversible, and most aprotinin-protease complexes will dissociate at extreme pH levels >10 or <3. Structurally, Aprotinin is a monomeric globular protein derived from bovine lung that consists of 58 amino acids, arranged in a single polypeptide chain with three crosslinking disulfide bridges._x000D_ Unit Definition_x000D_ One Trypsin Inhibitor Unit (TIU) will decrease the activity of two trypsin units by 50%, where one trypsin unit will hydrolyze 1.0 μmole of N-alpha-benzoyl-DL-arginine p-nitroanilide per minute at pH 7.8 and 25°C. Another commonly used unit is the KIU, with 1 TIU = 1,300 KIU._x000D_ One trypsin inhibitor unit (TIU) will decrease the activity of 2 trypsin units by 50% where one trypsin unit will hydrolyze 1.0 μmole of N-α-benzoyl-DL-arginine p-nitroanilide (BAPNA) per min at pH 7.8 at 25 °C._x000D_ Preparation Note_x000D_ A further purification of A1153 to yield a product with slightly higher activity and purity