Introduction
Aprotinin is a protease inhibitor that acts on various enzymes like chymotrypsin, kallikrein, plasmin, and trypsin. Found in blood and tissues, with high concentrations in the lungs, it plays a role in reducing inflammation and maintaining the balance of glycoproteins. Aprotinin helps preserve glycoproteins in platelets, preventing their loss (e.g., GpIb, GpIIb/IIIa), while in granulocytes, it inhibits the expression of pro-inflammatory adhesive glycoproteins (e.g., CD11b).
Description
Aprotinin, a naturally occurring proteinase inhibitor, is a polypeptide comprising 58 amino acids with the chemical formula C284H432N84O79S7. It features a single polypeptide chain structure, interlinked by three disulfide bridges, and possesses a molecular weight of 6512.
Physical Appearance
The product appears as a white powder, sterilized through filtration and lyophilized (freeze-dried).
Formulation
The protein was lyophilized without any additional ingredients to a concentration of 1mg/ml.
Solubility
For reconstitution of lyophilized Aprotinin, it is advised to use sterile 18MΩ-cm H2O to achieve a concentration of at least 100µg/ml. This solution can be further diluted in other aqueous solutions as needed.
Stability
Lyophilized Aprotinin remains stable at room temperature for up to 3 weeks; however, it is recommended to store it desiccated below -18°C. After reconstitution, Aprotinin should be kept at 4°C for a period of 2-7 days. For long-term storage, it is advisable to freeze it below -18°C. The addition of a carrier protein (0.1% HSA or BSA) is recommended for extended storage. Repeated freeze-thaw cycles should be avoided.
Specific Activity
The specific activity of the Aprotinin is measured as 6,120 KIU (Kallikrein Inactivator Units) per mg, determined at 3.4 pH according to European Pharmacopoeia Units (Eur.U/mg).
Synonyms
Pancreatic trypsin inhibitor, Basic protease inhibitor, BPI, BPTI, Aprotinin, AP.
