Disease	Score

Substances	Interaction	Organism	Category

Substances	Interaction	Organism	Category

Myeloperoxidase (MPO) produces hypochlorous acid (HOCl) from hydrogen peroxide (H2O2) and chloride anion (Cl−) during the neutrophil's respiratory burst. It requires heme as a cofactor.

Furthermore, it oxidizes tyrosine to tyrosyl radical using hydrogen peroxide as an oxidizing agent.  Hypochlorous acid and tyrosyl radical are toxic to cell, so they are used by the neutrophil to kill bacteria and other pathogens.

However, this hypochlorous acid may also cause oxidative damage in host tissue. Moreover, MPO oxidation of apoA-I reduces HDL-mediated inhibition of apoptosis and inflammation. In addition, MPO mediates protein nitrosylation and the formation of 3-chlorotyrosine and dityrosine crosslinks.

Recent studies have reported an association between elevated myeloperoxidase levels and the severity of heart disease.

Elevated MPO levels more than doubled the risk for cardiovascular mortality over a 13-year period and could serve as a sensitive predictor for heart attacks in patients with chest pain. It has also been suggested that myeloperoxidase plays a significant role in the development of the atherosclerotic lesion and rendering plaques unstable.

Measuring both MPO and CRP (C-reactive protein; a general and cardiac-related marker of inflammation) provided added benefit for risk prediction than just measuring CRP alone.

     From NCBI Gene: Alzheimer's diseaseMyeloperoxidase deficiencyFrom UniProt: Myeloperoxidase deficiency (MPOD): A disorder characterized by decreased myeloperoxidase activity in neutrophils and monocytes that results in disseminated candidiasis. [MIM:254600]

     From NCBI Gene: Myeloperoxidase (MPO) is a heme protein synthesized during myeloid differentiation that constitutes the major component of neutrophil azurophilic granules. Produced as a single chain precursor, myeloperoxidase is subsequently cleaved into a light and heavy chain. The mature myeloperoxidase is a tetramer composed of 2 light chains and 2 heavy chains. This enzyme produces hypohalous acids central to the microbicidal activity of neutrophils. [provided by RefSeq, Nov 2014] From UniProt: 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.

Condition	Change (log2fold)	Comparison	Species	Experimental variables	Experiment name

Condition	Change (log2fold)	Comparison	Species	Experimental variables	Experiment name

The following transcription factors affect gene expression:

• GR
• GR-alpha
• GR-beta
• p53
• Sp1
• AML1a
• Pax-5
• GATA-3

Cofactor:

Binds 1 heme b (iron(II)-protoporphyrin IX) group covalently per monomer.

Molecular Function:

• Chromatin Binding
• Heme Binding
• Heparin Binding
• Metal Ion Binding
• Peroxidase Activity

Biological Processes:

• Aging
• Defense Response
• Defense Response To Bacterium
• Defense Response To Fungus
• Hydrogen Peroxide Catabolic Process
• Hypochlorous Acid Biosynthetic Process
• Low-Density Lipoprotein Particle Remodeling
• Negative Regulation Of Apoptotic Process
• Negative Regulation Of Growth Of Symbiont In Host
• Oxidation-Reduction Process
• Removal Of Superoxide Radicals
• Respiratory Burst Involved In Defense Response
• Response To Food
• Response To Gold Nanoparticle
• Response To Lipopolysaccharide
• Response To Mechanical Stimulus
• Response To Oxidative Stress
• Response To Yeast

Drug Bank:

• Calcipotriol
• Human Serum Albumin
• L-Carnitine
• Mesalazine
• Capsaicin
• Carboplatin
• Cefaclor
• Cefdinir
• Cysteamine
• Dapsone
• Enoxaparin
• Melatonin
• Nabumetone
• Oxaliplatin
• Propylthiouracil
• Ticlopidine
• Tiopronin
• Aminosalicylic Acid
• Bivalirudin
• Cisplatin
• Octreotide
• Tolmetin

*synonyms