Part of the host defense system of polymorphonuclear leukocytes. It is responsible for microbicidal activity against a wide range of organisms. In the stimulated PMN, MPO catalyzes the production of hypohalous acids, primarily hypochlorous acid in physiologic situations, and other toxic intermediates that greatly enhance PMN microbicidal activity. Homodimer; disulfide-linked. Each monomer consists of a light and a heavy chain. Belongs to the peroxidase family. XPO subfamily. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Molecular Function: chromatin binding; heme binding; heparin binding; metal ion binding; peroxidase activity
Biological Process: aging; defense response; defense response to fungus; hydrogen peroxide catabolic process; negative regulation of apoptosis; removal of superoxide radicals; respiratory burst during defense response; response to food; response to lipopolysaccharide; response to mechanical stimulus; response to oxidative stress; response to yeast
LTP: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.