Description
Myeloperoxidase (MPO) is a peroxidase enzyme that in humans is encoded by the MPO gene on chromosome 17. MPO is most abundantly expressed in neutrophil granulocytes (a subtype of white blood cells), and produces hypohalous acids to carry out their antimicrobial activity. It is a lysosomal protein stored in azurophilic granules of the neutrophil and released into the extracellular space during degranulation. MPO has a heme pigment, which causes its green color in secretions rich in neutrophils, such as pus and some forms of mucus.
Form
Lyophilized from 50 mM sodium acetate buffer, pH 6.0, 0.1 M sodium chloride
Enzyme Commission Number
EC 1.11.1.7
Activity
> 50 units/mg protein
Unit Definition
One unit will produce an increase in absorbance (A470) of 1.0 per min at pH 7.0 and 25°C, calculated from the initial rate of reaction using guaiacol as substrate. Total reaction volume: 3.035 mL.
Buffer
H2O: soluble ; aqueous buffers such as 50 mM sodium acetate: soluble (Freezing of the enzyme in solution may result in a substantial loss of activity.)
Warnings
Lysosomal heme-containing protein. Source material tested and found negative for antibody to HIV and for HBSAG.
Pathway
C-MYB transcription factor network, organism-specific biosystem; Folate Metabolism, organism-specific biosystem; IL23-mediated signaling events, organism-specific biosystem; Phagosome, organism-specific biosystem; Phagosome, conserved biosystem; Selenium Pathway, organism-specific biosystem; Transcriptional misregulation in cancer, organism-specific biosystem
Function
chromatin binding; heme binding; heparin binding; metal ion binding; oxidoreductase activity; peroxidase activity
Synonyms
MPO; myeloperoxidase; Peroxidase; myelo; EC 1.11.1.7; 9003-99-0