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Eosinophil peroxidase is an enzyme found within the eosinophil granulocytes, innate immune cells of humans and mammals. This oxidoreductase protein is encoded by the gene ''EPX'', expressed within these myeloid cells. EPO shares many similarities with its orthologous peroxidases, myeloperoxidase (MPO), lactoperoxidase (LPO), and thyroid peroxidase (TPO). The protein is concentrated in secretory granules within eosinophils. Eosinophil peroxidase is a heme peroxidase, its activities including the oxidation of halide ions to bacteriocidal reactive oxygen species, the cationic disruption of bacterial cell walls, and the post-translational modification of protein amino acid residues. The major function of eosinophil peroxidase is to catalyze the formation of hypohalous acids from hydrogen peroxide and halide ions in solution. For example: : H2O2 + Cl- → HOCl + H2O Hypohalous acids formed from halides or pseudohalides are potent oxidizing agents. == Gene == The open reading frame of human eosinophil peroxidase was found to have a length of 2,106 base pairs (bp). This comprises a 381-bp prosequence, a 333-bp sequence encoding the light chain and a 1,392-bp sequence encoding the heavy chain. In addition to these there is a 452-bp untranslated region at the 3' end containing the AATAAA polyadenylation signal. The promoter sequence for human eosinophil peroxidase is an unusually strong promoter. All the major regulatory elements are located within 100 bp upstream of the gene. The profile of ''EPX'' expression has been characterized and is available online via (BioGPS ). This dataset indicates that both in humans and mice, ''EPX'' is only expressed in the bone marrow. At this level, it is more than 30 times the average level of expression over all tissues in the body. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Eosinophil peroxidase」の詳細全文を読む スポンサード リンク
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