eosinophil peroxidase (EPX, EPER, EPO, EPP)

Function: - peroxidase of eosinophils Structure: - tetramer of two light chains & two heavy chains derived from common precursor - binds 1 heme B (iron-protoporphyrin IX) covalently through ester linkages to hydroxylated methyl groups formed auto-catalytically with hydrogen peroxide at the heme C-1 & C-5 positions - ester linkage to Asp-232 was observed in 30% of the chains - belongs to the peroxidase family, XPO subfamily Compartment: - cytoplasmic granule Expression: eosinophils Pathology: - defects in EPX are the cause of eosinophil peroxidase deficiency

General

glycoprotein peroxidase

Properties

SIZE: entity length = 715 aa MW = 81 kD COMPARTMENT: cytoplasm cell nucleus MOTIF: signal sequence {1-17} N-glycosylation site {N52} N-glycosylation site {N113} cysteine residue {C141} MODIFICATION: cysteine residue {C152} cysteine residue {C152} MODIFICATION: cysteine residue {C141} heme-binding site [232-232] histidine residue {H233} Ca+2-binding site SITE: 234-234 cysteine residue {C253} MODIFICATION: cysteine residue {C263} cysteine residue {C257} MODIFICATION: cysteine residue {C281} cysteine residue {C263} MODIFICATION: cysteine residue {C253} cysteine residue {C281} MODIFICATION: cysteine residue {C257} Ca+2-binding site SITE: 306-306 Ca+2-binding site SITE: 308-308 Ca+2-binding site SITE: 310-310 Ca+2-binding site SITE: 312-312 N-glycosylation site {N327} cysteine residue {C359} MODIFICATION: cysteine residue {C370} N-glycosylation site {N363} cysteine residue {C370} MODIFICATION: cysteine residue {C359} arginine residue {377} heme-binding site [380-380] Iron [Fe]-binding site SITE: 474-474 cysteine residue {C578} MODIFICATION: cysteine residue {C635} cysteine residue {C635} MODIFICATION: cysteine residue {C578} cysteine residue {C676} MODIFICATION: cysteine residue {C701} N-glycosylation site {N700} cysteine residue {C701} MODIFICATION: cysteine residue {C676} N-glycosylation site {N708}

Database Correlations

OMIM correlations MORBIDMAP 131399 UniProt P11678 Pfam PF03098 Entrez Gene 8288 Kegg hsa:8288 ENZYME 1.11.1.7