Q8R481 · PERL_MESAU

Function

function

Heme-containing oxidoreductase which catalyzes the conversion of thiocyanate (SCN-) into antimicrobial agent hypothiocyanous acid (OSCN-) in the presence of hydrogen peroxide (H2O2). Also involved in the conversion of iodide (I-) into hypoiodite (IO-) in the presence of H2O2 (By similarity).
Responsible for the inactivation of a wide range of micro-organisms and hence, important component of defense mechanism. May be implicated in airway host defense against infection (By similarity).
May contribute to maintaining an appropriate H2O2 cellular level, therefore protecting cells from H2O2-caused injuries and inflammation (By similarity).

Miscellaneous

Thiocyanate (SCN-) and hypothiocyanite (OSCN-) are bound in the distal heme cavity. The iodide ion (I-) occupies a position which is stabilized by the interactions with heme moiety, His-224, Arg-370 and Glu-373. Hydrogen peroxide is held between the heme iron and His-224.

Catalytic activity

Cofactor

Protein has several cofactor binding sites:
Ca2+ (UniProtKB | Rhea| CHEBI:29108 )

Note: Binds 1 Ca2+ ion per heterodimer.
heme b (UniProtKB | Rhea| CHEBI:60344 )

Note: Binds 1 heme b (iron(II)-protoporphyrin IX) group covalently per heterodimer.

Features

Showing features for binding site, active site, site.

TypeIDPosition(s)Description
Binding site223heme b (UniProtKB | ChEBI); covalent
Active site224Proton acceptor
Binding site225Ca2+ (UniProtKB | ChEBI)
Binding site299Ca2+ (UniProtKB | ChEBI)
Binding site301Ca2+ (UniProtKB | ChEBI)
Binding site303Ca2+ (UniProtKB | ChEBI)
Binding site305Ca2+ (UniProtKB | ChEBI)
Site370Transition state stabilizer
Binding site373heme b (UniProtKB | ChEBI); covalent
Binding site466Fe (UniProtKB | ChEBI) of heme b (UniProtKB | ChEBI); axial binding residue

GO annotations

AspectTerm
Cellular Componentbasolateral plasma membrane
Cellular Componentcytoplasm
Cellular Componentextracellular space
Molecular Functionheme binding
Molecular Functionlactoperoxidase activity
Molecular Functionmetal ion binding
Molecular Functionperoxidase activity
Molecular Functionthiocyanate peroxidase activity
Biological Processdefense response to bacterium
Biological Processdetection of chemical stimulus involved in sensory perception of bitter taste
Biological Processresponse to oxidative stress

Keywords

Enzyme and pathway databases

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Lactoperoxidase
  • EC number
  • Short names
    LPO
  • Alternative names
    • Lacrimal gland peroxidase

Gene names

    • Name
      LPO

Organism names

  • Taxonomic identifier
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Glires > Rodentia > Myomorpha > Muroidea > Cricetidae > Cricetinae > Mesocricetus

Accessions

  • Primary accession
    Q8R481

Proteomes

Subcellular Location

Secreted
Cytoplasm
Note: Secreted by the lacrimal gland into tears.

Keywords

PTM/Processing

Features

Showing features for signal, propeptide, glycosylation, chain, disulfide bond, modified residue.

TypeIDPosition(s)Description
Signal1-22
PropeptidePRO_000043329923-98
Glycosylation25N-linked (GlcNAc...) asparagine
ChainPRO_000043330099-710Lactoperoxidase
Glycosylation104N-linked (GlcNAc...) asparagine
Disulfide bond130↔143
Glycosylation131N-linked (GlcNAc...) asparagine
Glycosylation238N-linked (GlcNAc...) asparagine
Disulfide bond244↔254
Disulfide bond248↔272
Modified residue313Phosphoserine
Glycosylation320N-linked (GlcNAc...) asparagine
Disulfide bond352↔363
Modified residue4803'-nitrotyrosine
Disulfide bond571↔628
Disulfide bond669↔694

Keywords

PTM databases

Expression

Tissue specificity

Expressed in the lacrimal gland with higher levels and 3-fold higher activity in adult females than males and secreted into tears (at protein level).

Induction

Repressed by the androgen dihydrotestosterone (DHT) and the estrogen estradiol (E2) (at protein level).

Interaction

Protein-protein interaction databases

Structure

Family & Domains

Sequence similarities

Belongs to the peroxidase family. XPO subfamily.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    710
  • Mass (Da)
    80,219
  • Last updated
    2002-06-01 v1
  • Checksum
    AD8C9359DB1C270F
MKVLLRLPALLASLTLLQMAASTRNATRTATIRETVDEVKVQVNKAFLDSRDRLKTDMSNLAPTVRHLSGYLKQAKGRTRTAIRVGQVWEQSLKRLRRMVPLTNVTGQGLDLTSLSWEVGCGHPAPTVTCNISNPYRTITGDCNNRKNPELGSANRALARWLPAEYEDGLSLPFGWTPGKTRNGFPLPQPRDVSNQVLDYLNEEEILDQNRSLLFMQWGQIVDHDLDFAPETEMGSDNYSKAQCDELCIQGDNCFPIMFPKGDPKLKTQGKCLPFFRAGFVCPTSPYQSLAREQINALTSFMDASMVYGSEPSLANRLRNLSSPLGLMAVNEEVSDHGRPLLPFVNVKPSPCEVINRTAGVPCFLAGDSRASEQILLATSHTLFLREHNRLARELSRLNPQWDGEKLYQEARRIMGALIQIITFRDYLPILLGDELQKWIPPYQGYKETVDPRISNVFTFAFRFGHLEVPSTVSRLDENYQPWGSEPELPLHKLFFNTWRVVKDGGIDPLVRGLLAKKAKLAHQDKMMTGELRNMLFQPNHTVHGFDLAAINIQRCRDHGQPGYNSWRAFCGLSQPKTLEELSAVLRNEVLAKKLMDLYGTPDNIDIWLGAIAEPLVRRGRVGPLLTCLLGQQFQRIRDGDRFWWENPGVFTEKQRDSLQKMSFSRLVCDNTGINKVPLNPFQPNSYPHSFVDCSAIEKLDLTPWASVKK

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AF498045
EMBL· GenBank· DDBJ
AAM15535.1
EMBL· GenBank· DDBJ
mRNA

Genome annotation databases

Similar Proteins

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