Target type: molecularfunction
Catalysis of the reaction: histamine + H2O + O2 = imidazole-4-acetaldehyde + NH3 + hydrogen peroxide + H+. [MetaCyc:RXN-9600]
Histamine oxidase activity is a crucial enzymatic process that plays a significant role in regulating histamine levels in various biological systems. Histamine, a biogenic amine, is a potent mediator of inflammatory responses, allergic reactions, and other physiological processes. Its excessive accumulation can lead to detrimental effects. Histamine oxidase, also known as diamine oxidase (DAO), is an enzyme that specifically catalyzes the oxidative deamination of histamine, converting it into the inactive metabolite, imidazoleacetic acid. This enzymatic reaction involves the removal of the amino group from histamine, followed by the addition of oxygen and the formation of hydrogen peroxide. The catalytic mechanism of histamine oxidase typically involves a two-step process: 1) Oxidation of histamine to an intermediate imine compound. 2) Hydrolysis of the imine compound to yield imidazoleacetic acid and ammonia. Histamine oxidase is a copper-containing enzyme, with the copper ion acting as a cofactor in the catalytic process. The enzyme's active site contains a specific binding pocket that recognizes and binds to histamine, facilitating the oxidative deamination reaction. Histamine oxidase activity is crucial for maintaining normal histamine levels and preventing excessive histamine accumulation in tissues. Deficiencies in histamine oxidase activity can result in histamine intolerance, a condition characterized by an accumulation of histamine in the body, leading to various symptoms such as headaches, skin rashes, and gastrointestinal disturbances. In contrast, elevated histamine oxidase activity has been associated with certain disease states, such as Alzheimer's disease. Overall, histamine oxidase activity plays a critical role in regulating histamine levels, contributing to the maintenance of normal physiological functions and preventing the development of histamine-related disorders.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Amiloride-sensitive amine oxidase [copper-containing] | An amiloride-sensitive amine oxidase [copper-containing] that is encoded in the genome of human. [PRO:DNx, UniProtKB:P19801] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| diminazene | diminazene : A triazene derivative that is triazene in which each of the terminal nitrogens is substituted by a 4-carbamimidoylphenyl group. Diminazene: An effective trypanocidal agent. | carboxamidine; triazene derivative | antiparasitic agent; trypanocidal drug |
| pentamidine | pentamidine : A diether consisting of pentane-1,5-diol in which both hydroxyl hydrogens have been replaced by 4-amidinophenyl groups. A trypanocidal drug that is used for treatment of cutaneous leishmaniasis and Chagas disease. Pentamidine: Antiprotozoal agent effective in trypanosomiasis, leishmaniasis, and some fungal infections; used in treatment of PNEUMOCYSTIS pneumonia in HIV-infected patients. It may cause diabetes mellitus, central nervous system damage, and other toxic effects. | aromatic ether; carboxamidine; diether | anti-inflammatory agent; antifungal agent; calmodulin antagonist; chemokine receptor 5 antagonist; EC 2.3.1.48 (histone acetyltransferase) inhibitor; NMDA receptor antagonist; S100 calcium-binding protein B inhibitor; trypanocidal drug; xenobiotic |
| benzylamine | aminotoluene : Any member of the class of toluenes carrying one or more amino groups. | aralkylamine; primary amine | allergen; EC 3.5.5.1 (nitrilase) inhibitor; plant metabolite |