Human Myeloperoxidase/MPO Recombinant Protein (His Tag)

Background: Myeloperoxidase (MPO) is a heme-containingenzyme belonging to the XPO subfamily of peroxidases. It is an abundant neutrophil and monocyte glycoprotein thatcatalyzes the hydrogen peroxide-dependentconversion of chloride, bromide, and iodide to multiple reactive species. Post-translationalprocessing of MPO involvesthe insertion of a heme moiety and the proteolytic removal of both a propeptide and a 6 aa internal peptide. This results in a disulfide-linkeddimer composed of a60 kDa heavy and 12 kDa light chain that associate into a 150 kDa enzymatically active tetramer. The tetramer contains two heme groups and one disulfide bondbetween the heavy chains. Alternate splicing generates two additional isoforms of MPO, one with a 32 aa insertion in the light chain, and another with a deletion ofthe signal sequence and part of the propeptide. Human and mouse MPO share 87% aa sequence identity. MPO activity results in protein nitrosylation and theformation of 3-chlorotyrosineand dityrosine crosslinks. MPO is also associated with a variety of other diseases, and inhibits vasodilation in inflammation by depleting the levelsof NO. Serum albumin functions as a carrier protein during MPO movement to the basolateral side of epithelial cells. MPO is stored in neutrophil azurophilicgranules. Upon cellular activation, it is deposited into pathogen-containingphagosomes.