Description_x000D_ Application_x000D_ Aprotinin from bovine lung has been used in insulin and glucagon-like peptide-1 assay. It has also been used a in western blotting._x000D_ Aprotinin is largely used as an inhibitor of trypsin._x000D_ Packaging_x000D_ 10, 25 mg in poly bottle_x000D_ 100, 250 mg in glass bottle_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_ Aprotinin is a natural polypeptide of 58 amino acids. It possesses hemostatic/antiplasmin action and helps to reduce bleeding during surgeries. This prevents the necessity of blood transfusion._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_ When benzoyl-L-arginine ethyl ester (BAEE) is used as substrate one BAPNA unit is approx. 45BAEE μmolar units at pH8.0 at 25°C or approx. 9,000 BAEE A253 units at pH7.6 at 25°C._x000D_ Preparation Note_x000D_ This product is a lyophilized powder that has been cell culture tested. It has an activity of 3-7 TIU/mg.