Aprotinin

Aprotinin from bovine lung has been used in insulin and glucagon-like peptide-1 assay. It has also been used a in western blotting.

Aprotinin is largely used as an inhibitor of trypsin.

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.

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.

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.

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.

This product is a lyophilized powder that has been cell culture tested. It has an activity of 3-7 TIU/mg.