Merck, L2005-1MG, Lactoperoxidase from bovine milk

General description
Lactoperoxidase is a major enzyme present in bovine milk and belongs to the peroxidase family. It is present in both plants and animals. The enzyme structure comprises a single polypeptide chain made up of 612 amino acid residues.
Application
Lactoperoxidase from bovine milk has been used as a standard for milk lactoperoxidase to study the role of H₂O₂ in the inhibition of Staphylococcus aureus growth by Lactococcus garvieae in the presence of lactoperoxidase in raw milk. It has also been used in lactoperoxidase-mediated iodination to prepare radiolabeled peptides.
Biochem/physiol Actions
Lactoperoxidase catalyzes the oxidation of iodide to iodine by hydrogen peroxide. This activity provides a gentle, specific alternative to chloramine T for the radioiodination of proteins and DNA.
Lactoperoxidase contributes to the antimicrobial system of milk by inactivating a wide range of micro-organisms. This lactoperoxidase-mediated antimicrobial system is also identified in human secretions such as tear-fluid, saliva, and milk. Lactoperoxidase catalyzes the oxidation of molecules by releasing H2O2. The product exhibits antimicrobial activity.
Analysis Note
Protein determined by Lowry method.
Other Notes
One unit will oxidize 1.0 μmole of 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) at pH 5.5 at 25 °C.