HGNC Approved Gene Symbol: LPO
Cytogenetic location: 17q22 Genomic coordinates (GRCh38): 17:58,238,584-58,268,518 (from NCBI)
Lactoperoxidase (EC 1.11.1.7) is a natural antibacterial agent in bovine milk, a medium otherwise rich in its ability to support bacterial growth. Milk LPO levels vary among species, ranging from little or none in humans to very high concentrations in guinea pigs. Human colostrum contains LPO activity; however, the levels drop rapidly within 1 week postpartum (summary by Dull et al., 1990).
Dull et al. (1990) used peptide sequences obtained from cyanogen bromide fragments of bovine lactoperoxidase to design oligonucleotide probes for screening a cDNA library constructed from bovine mammary tissue. Overlapping clones were obtained, which encoded an amino acid sequence homologous to those recently reported for myeloperoxidase (MPO; 606989), thyroid peroxidase (TPO; 606765), and eosinophil peroxidase (EPX; 131399). The predicted mature protein matched previous molecular mass estimates of 78.5 kD. Among 8 bovine tissues tested, transcription was detected only in mammary tissue. Using bovine LPO cDNA as a probe, Dull et al. (1990) found a single hybridizing clone in a human mammary gland cDNA library. This clone encoded the carboxy-terminal 324 residues of a peroxidase distinct from the other 3 known human peroxidases and with close similarity to bovine LPO.
Ueda et al. (1997) cloned the human LPO gene, which encodes a deduced 712-amino acid protein.
Ueda et al. (1997) determined that the LPO gene contains 12 exons and spans 28 kb, including a 1.5-kb 5-prime upstream region. The similarity in gene organization and sequence among LPO, MPO, and EPX indicated that these peroxidase genes may have evolved from a common ancestral gene.
Ueda et al. (1997) mapped the LPO gene to chromosome 17q23.1, 2.5 kb from the MPO gene. The 2 genes were arranged in a tail-to-tail configuration.
Dull, T. J., Uyeda, C., Strosberg, A. D., Nedwin, G., Seilhamer, J. J. Molecular cloning of cDNAs encoding bovine and human lactoperoxidase. DNA Cell Biol. 9: 499-509, 1990. [PubMed: 2222811] [Full Text: https://doi.org/10.1089/dna.1990.9.499]
Ueda, T., Sakamaki, K., Kuroki, T., Yano, I., Nagata, S. Molecular cloning and characterization of the chromosomal gene for human lactoperoxidase. Europ. J. Biochem. 243: 32-41, 1997. [PubMed: 9030719] [Full Text: https://doi.org/10.1111/j.1432-1033.1997.0032a.x]