Eosinophil peroxidase: Difference between revisions

Latest revision as of 12:38, 31 December 2024

Eosinophil peroxidase (EPX) is an enzyme that is predominantly found in eosinophils, a type of white blood cell involved in the body's immune response. This enzyme plays a crucial role in the immune system by contributing to the destruction of pathogens and the modulation of inflammatory responses.

Structure[edit]

Eosinophil peroxidase is a heme-containing enzyme that belongs to the peroxidase family. It is composed of a single polypeptide chain and contains a heme prosthetic group that is essential for its enzymatic activity. The enzyme is stored in the granules of eosinophils and is released upon activation of these cells.

Function[edit]

The primary function of eosinophil peroxidase is to catalyze the oxidation of various substrates using hydrogen peroxide as an oxidizing agent. This reaction results in the production of hypobromous acid and other reactive oxygen species, which are potent antimicrobial agents. These reactive species contribute to the killing of bacteria, parasites, and other microorganisms that invade the body.

Role in Disease[edit]

Eosinophil peroxidase is implicated in several diseases due to its role in inflammation and tissue damage. Elevated levels of eosinophil peroxidase are often observed in conditions such as asthma, allergic reactions, and eosinophilic esophagitis. In these conditions, the excessive release of eosinophil peroxidase and other eosinophil-derived mediators can lead to tissue damage and exacerbate disease symptoms.

Clinical Significance[edit]

The measurement of eosinophil peroxidase levels in blood and tissue samples can serve as a biomarker for eosinophil activation and inflammation. Therapeutic strategies aimed at modulating eosinophil peroxidase activity are being explored as potential treatments for eosinophil-associated diseases.

External Links[edit]

[Eosinophil peroxidase at UniProt]
[Eosinophil peroxidase at GeneCards]

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-[[File:Eosinophil peroxidase - Demonstration of protoporphyrin linkage.gif|thumb|left|upright=1.5|alt=Left: protoporphyrin IX; Right: modification for ester linkage.|Left:]] [[File:Active site of eosinophil peroxidase.gif|thumb|right|upright=1.5|alt=Active site of eosinophil peroxidase.|Active site of eosinophil peroxidase in the resting (reduced) state. Pictured: Proximal histidine-asparagine interaction (bottom); distal histidine and bound water (top). In the oxidized form, the oxyferryl radical takes the place of the bound solvent molecule, and the halide substrate binds alongside that. Not pictured: other bound solvent water molecules. Refer to PDB crystal structures or ''refs.<ref name="pmid16288970" /> and.<ref name="pmid17534531" />'']] '''Eosinophil peroxidase''' (EPO) is a [[heme]]-containing [[enzyme]] that is a major component of the large granules found in [[eosinophils]], a type of [[white blood cells]]. Eosinophils are primarily involved in the body's immune response to parasitic infections and are also implicated in the pathogenesis of various [[allergic reactions]] and [[asthma]]. EPO plays a critical role in the immune defense mechanism through the production of reactive oxygen species and the generation of [[halogenating agents]], which are toxic to pathogens.
+{{Infobox protein
+| name = Eosinophil peroxidase
+| image = Eosinophil_peroxidase_structure.png
+| caption = Structure of eosinophil peroxidase
+| symbol = EPX
+| HGNCid = 3375
+| OMIM = 131399
+| ECnumber = 1.11.1.7
+| chromosome = 17
+| arm = q
+| band = 22
+}}
-==Structure and Function==
+'''Eosinophil peroxidase''' (EPX) is an enzyme that is predominantly found in [[eosinophils]], a type of [[white blood cell]] involved in the body's immune response. This enzyme plays a crucial role in the [[immune system]] by contributing to the destruction of [[pathogens]] and the modulation of [[inflammatory responses]].
-Eosinophil peroxidase is a member of the peroxidase-cyclooxygenase superfamily. It is similar in structure to [[myeloperoxidase]] (MPO), which is found in [[neutrophils]], another type of white blood cell. However, EPO has unique structural features and enzymatic activities that distinguish it from MPO. EPO catalyzes the reaction of hydrogen peroxide with chloride and bromide ions to produce hypochlorous acid and hypobromous acid, respectively. These reactive compounds are potent antimicrobials that can kill a wide range of pathogens, including bacteria, viruses, and parasites.
+==Structure==
+Eosinophil peroxidase is a [[heme]]-containing enzyme that belongs to the [[peroxidase]] family. It is composed of a single polypeptide chain and contains a heme prosthetic group that is essential for its enzymatic activity. The enzyme is stored in the granules of eosinophils and is released upon activation of these cells.
+==Function==
+The primary function of eosinophil peroxidase is to catalyze the oxidation of various substrates using [[hydrogen peroxide]] as an oxidizing agent. This reaction results in the production of [[hypobromous acid]] and other reactive oxygen species, which are potent antimicrobial agents. These reactive species contribute to the killing of [[bacteria]], [[parasites]], and other [[microorganisms]] that invade the body.
 ==Role in Disease==
-While EPO is essential for the immune response to pathogens, its activity must be tightly regulated. Excessive or misplaced action of EPO can contribute to tissue damage and inflammation, playing a role in the development of diseases such as asthma, [[eosinophilic esophagitis]], and other eosinophil-related disorders. In asthma, for example, the release of EPO and other eosinophilic granule proteins can damage the airway tissue and exacerbate the inflammatory response.
+Eosinophil peroxidase is implicated in several [[diseases]] due to its role in inflammation and tissue damage. Elevated levels of eosinophil peroxidase are often observed in conditions such as [[asthma]], [[allergic reactions]], and [[eosinophilic esophagitis]]. In these conditions, the excessive release of eosinophil peroxidase and other eosinophil-derived mediators can lead to tissue damage and exacerbate disease symptoms.
 ==Clinical Significance==
-The measurement of EPO levels in biological fluids can serve as a marker for eosinophil activation and has potential diagnostic value in diseases characterized by eosinophilic inflammation. Additionally, targeting EPO or its pathways has been explored as a therapeutic strategy to mitigate the detrimental effects of eosinophilic inflammation in allergic diseases and asthma.
+The measurement of eosinophil peroxidase levels in [[blood]] and [[tissue]] samples can serve as a biomarker for eosinophil activation and inflammation. Therapeutic strategies aimed at modulating eosinophil peroxidase activity are being explored as potential treatments for eosinophil-associated diseases.
-==Research Directions==
+==See Also==
-Research on eosinophil peroxidase continues to explore its exact mechanisms of action, its role in disease, and potential therapeutic interventions. Understanding the balance between its protective roles in immunity and its contributions to pathology is crucial for developing targeted therapies that can mitigate eosinophilic inflammation without compromising immune defense.
+* [[Eosinophil]]
+* [[Peroxidase]]
+* [[Immune system]]
+* [[Inflammation]]
+==External Links==
+* [Eosinophil peroxidase at UniProt]
+* [Eosinophil peroxidase at GeneCards]
+{{Enzymes}}
+{{Immune system}}
 [[Category:Enzymes]]
 [[Category:Immune system]]
 [[Category:Proteins]]
+[[Category:Human proteins]]
-{{biochemistry-stub}}