Mouse Myeloperoxidase (MPO) is a heme-containing enzyme belonging to the XPO subfamily of peroxidases. It is an abundant neutrophil and monocyte glycoprotein that catalyzes the hydrogen peroxide-dependent conversion of chloride, bromide, and iodide to multiple reactive species. Post-translational processing of human MPO involves the insertion of a heme moiety and the proteolytic removal of both a propeptide and a 6 aa internal peptide. This results in a disulfide-linked dimer composed of a 60kD heavy and 12kD light chain that associate into a 150kD enzymatically active tetramer. The tetramer contains two heme groups and one disulfide bond between the heavy chains. Mouse and human MPO share 87% aa sequence identity. MPO activity results in protein nitrosylation and the formation of 3-chlorotyrosine and dityrosine crosslinks. Modification of ApoB100, as well as the lipid and cholesterol components of LDL and HDL, promotes the development of atherosclerosis. MPO is also associated with a variety of other diseases, and inhibits vasodilation in inflammation by depleting the levels of NO. Serum albumin functions as a carrier protein during MPO movement to the basolateral side of epithelial cells. MPO is stored in neutrophil azurophilic granules. Upon cellular activation, it is deposited into pathogen- containing phagosomes. While mice lacking MPO are impaired in clearing select microbial infections, MPO deficiency in humans does not necessarily result in heightened susceptibility to infections. Source: DNA sequence encoding mouse Myeloperoxidase (Met16-Thr 718, AAR99349) fused with a C-terminal 10-His tag expressed in NS0 cells. N-terminal Sequence Analysis: Met16 SDS-PAGE: 85-95kD, reducing conditions Activity: Measured by its ability to oxidize guaiacol in the presence of hydrogen peroxide (15). Specific Activity: > 8000 pmoles/min/ug under the described conditions. See protocol. Storage and Stability: Lyophilized and reconstituted products are stable for 6 months after receipt at -20C. Reconstitute with sterile ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
