lactoperoxidase; salivary peroxidase; SPO (LPO, SAPX)

Function: - may contribute to airway host defense against infection Donor + H₂O2 = oxidized donor + 2 H₂O Cofactor: - binds 1 Ca⁺² per heterodimer (putative) - binds 1 heme B (iron-protoporphyrin IX) group covalently per heterodimer (putative) Structure: belongs to the peroxidase family, XPO subfamily Compartment: secreted, extracellular space Expression: - mammary gland; milk & salivary gland - found in bronchial submucosal glands

General

Ca+2 binding protein glycoprotein milk protein peroxidase

Properties

SIZE: entity length = 712 aa MW = 80 kD COMPARTMENT: extracellular compartment MOTIF: signal sequence {1-26} N-glycosylation site {N106} cysteine residue {C132} MODIFICATION: cysteine residue {C145} cysteine residue {C145} MODIFICATION: cysteine residue {C132} N-glycosylation site {N212} heme-binding site [225-225] histidine residue {H226} Ca+2-binding site SITE: 227-227 cysteine residue {C246} MODIFICATION: cysteine residue {C256} cysteine residue {C250} MODIFICATION: cysteine residue {C274} cysteine residue {C256} MODIFICATION: cysteine residue {C246} cysteine residue {C274} MODIFICATION: cysteine residue {C250} Ca+2-binding site SITE: 301-301 Ca+2-binding site SITE: 303-303 Ca+2-binding site SITE: 305-305 Ca+2-binding site SITE: 307-307 N-glycosylation site {N322} cysteine residue {C354} MODIFICATION: cysteine residue {C365} N-glycosylation site {N358} cysteine residue {C365} MODIFICATION: cysteine residue {C354} arginine residue {372} heme-binding site [375-375] Iron [Fe]-binding site SITE: 468-468 cysteine residue {C573} MODIFICATION: cysteine residue {C630} cysteine residue {C630} MODIFICATION: cysteine residue {C573} cysteine residue {C671} MODIFICATION: cysteine residue {C696} cysteine residue {C696} MODIFICATION: cysteine residue {C671}

Database Correlations

OMIM correlations UniProt P22079 Pfam PF03098 Entrez Gene 4025 Kegg hsa:4025 ENZYME 1.11.1.7