How the assay works
In the Myeloperoxidase (MPO) Activity Assay Kit
(Colorimetric) protocol, myeloperoxidase produces HClO from H2O2 and Cl-. The
HClO reacts with taurine to generate the taurine chloramine, which subsequently
reacts with the DTNB probe to eliminate color (absorbance at 412 nm). The
absorbance is inversely proportional to the amount of MPO enzyme.
Myeloperoxidase (MPO) Activity Assay Kit (Colorimetric)
protocol summary:
- Add samples to wells (and assay buffer only to wells for
standards)
- Add reaction mix to sample wells and incubate for 30 min to 2 hrs
- Add stop mix and incubate for 10 min
- Add TNB reagent/standard to all wells and incubate for 5-10 min
- Analyze with a microplate reader
Technical Note: MPO is unlikely to be detectable in healthy
urine but may be elevated in the presence of infection.
How other researchers are using
Myeloperoxidase (MPO) Activity Assay Kit (Colorimetric) has
been used in a variety of sample type including:
HEK293T cells 1
Mice corneal lysates 2
Mouse uterus samples 3
References:
1-Han G et al. 2023
2-Singh A et al. 2023
3-Gao Y J et al. 2023
Related and recommended products
For fluorometric detection, we recommend the following kits:
- Myeloperoxidase (MPO) Activity Assay Kit (Fluorometric) Myeloperoxidase
(MPO) Activity Assay Kit (Fluorometric)ab111749
- Myeloperoxidase (MPO) Activity Assay Kit (Fluorometric - Red) Myeloperoxidase
(MPO) Activity Assay Kit (Fluorometric - Red)ab219925
- Myeloperoxidase (MPO) Peroxidation Activity Assay Kit (Fluorometric) Myeloperoxidase
(MPO) Peroxidation Activity Assay Kit (Fluorometric)ab273334
This product is manufactured by BioVision, an Abcam company
and was previously called K744 Myeloperoxidase (MPO) Colorimetric Activity
Assay Kit. K744-100 is the same size as the 100 test size of ab105136.
Myeloperoxidase (MPO) is a peroxidase enzyme (EC 1.11.1.7)
most abundantly expressed in neutrophil granulocytes. It is a lysosomal protein
stored in the azurophilic granules of the neutrophil. Myeloperoxidase contains
a heme pigment which causes its green color in secretions rich in neutrophils,
such as pus and some forms of mucus. Myeloperoxidase catalyzes the production
of hypochlorous acid (HClO) from hydrogen peroxide (H2O2)
and chloride anion (Cl-, or the equivalent from a non-chlorine halide).
Myeloperoxidase also oxidizes tyrosine to a tyrosyl radical using hydrogen
peroxide as an oxidizing agent.
The Safety Datasheet for this product has been updated for
certain countries. Please check the current version in the Support and
downloads section.
Supplementary info
This supplementary information is collated from multiple
sources and compiled automatically.
Activity summary
Myeloperoxidase also called MPO is an enzyme that plays a
critical role in the body's immune response. This protein has a mass of
approximately 150 kDa and exists as a dimer composed of heavy and light
polypeptide chains. Myeloperoxidase is prominently expressed in neutrophils and
monocytes which are types of white blood cells important for combating
infections. The enzyme catalyzes the production of hypochlorous acid and other
reactive substances by utilizing hydrogen peroxide and chloride ions. These reactive
substances help in neutralizing pathogens during the immune response.
Biological function summary
The generation of reactive oxygen species by myeloperoxidase
is essential for microbicidal activity. Myeloperoxidase functions as part of
the antimicrobial system in the phagosome which is the intracellular
compartment where pathogens are degraded. This enzyme works in conjunction with
other components of the immune system such as NADPH oxidase. By generating
hypochlorous acid MPO contributes to the oxidative burst a rapid release of
reactive oxygen species during the response to pathogens.
Pathways
Myeloperoxidase integrates into the immune defense and
inflammatory pathways. In particular it is associated with the neutrophil
degranulation pathway where it releases its enzymatic contents to fight off
microbes. MPO also interacts with proteins involved in oxidative stress
processes such as superoxide dismutase which moderates levels of reactive
oxygen species in cells. These interactions ensure balance in the immune
response preventing excessive tissue damage during inflammation.
Associated diseases and disorders
Dysregulated MPO activity can contribute to the development
of diseases. For instance myeloperoxidase is linked with atherosclerosis a
cardiovascular condition where inflammation and oxidative stress lead to plaque
formation in the arteries. It also associates with vasculitis an autoimmune
disorder causing inflammation of blood vessels. Both disorders can relate to
the inflammatory pathways that involve MPO and proteins like C-reactive protein
which serves as a marker of inflammation. Understanding MPO's role in these
conditions is important for effective therapeutic interventions.
