Sandbox WWC11
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| Dog glycosylated myeloperoxidase dimer: heavy chain (pink and yellow), light chain (grey and green) containing heme complex with Ca+2 ions (green), 1d5l | |||||||||
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| Ligands: | , , | ||||||||
| Activity: | Peroxidase, with EC number 1.11.1.7 | ||||||||
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| Resources: | FirstGlance, OCA, RCSB, PDBsum | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
Myeloperoxidase (MPO) is a protein found in nertrophil, the most common white blood cell. This enzyme generates hypochlorous acid (HOCl) from hydrogen peroxide in addition to other hypohalous acids depending on what is available in the cell. The HOCl is then used, in combination with other molecules, in an oxidative burst that kills bacteria and other potentially harmful invaders one taken up by the cell. This protein falls into a group of heme peroxidase enzymes. The role of these enzymes is to oxidize molecules using the heme[1]. [2]
This protein is composed of two identical monomers linked by a cystine bridge. The total molecular weight of this protein is 146kDa. These two monomers can work independently to each other and consist of a light and heavy amino acid chain. The active site on the protein consists of a deep crevice where a heme molecule is covalently attached. The deep pocket is believe to limit access to the heme and increase specificity for smaller molecules to be oxidized. This pocket also possesses a hydrophobic pocket for stabilization of substrate.[3]
Deficiency in this enzyme can cause immune deficiency, although most individuals with this mutation seem to be able to compensate with other, still unknown mechanisms. Over activation of myloperoxidase has been linked to increased inflammation and is being studied in relation to inceased risk of cardiovascular disease.[4] There are still many unknown surrounding the complete function and role that myeloperoxidase plays in the body's immune response. However, it has become clear that this protein is an integral piece in the system that warrants further research.
3D structures of myeloperoxidase3D structures of myeloperoxidase
Updated on 16-April-2016
1myp – MPO – dog
1mhl, 1cxp – hMPO C – human
3f9p - hMPO
1qo4 - MPO – Arabidopsis thaliana
1d2v – hMPO C + Br
1d5l – hMPO + CN
1d7w - hMPO + CN + Br
1dnu - hMPO + SCN
1dnw - hMPO + CN + SCN
3zs0, 3zs1, 4c1m - hMPO + inhibitor
4dl1 - hMPO + thioxanthine
4ejx - hMPO + ceruplasmin