Molecular Cloning of cDNAs Encoding Bovine and Human Lactoperoxidase

Abstract

Peptide sequences obtained from cyanogen bromide fragments of bovine lactoperoxidase (bLPO) were used to design oligonucleotide probes for library screening. These probes were used to screen a cDNA library constructed from bovine mammary tissue. Three overlapping clones were obtained, the longest of which (T3) contained a reading frame of 712 amino acid residues. The encoded amino acid sequence was homologous to those recently reported for myelo-, thyro-, and eosinophil peroxidases. Two possible amino termini of the mature enzyme were identified, and the predicted mature protein matched previous molecular weight estimates of 78,500. Of eight bovine tissues tested, transcription of T3 sequences were detected in mammary tissue only. Using the bLPO cDNA as a probe, a single hybridizing clone was found in a human mammary gland cDNA library. This clone (M1) encoded the carboxy-terminal 324 residues of a peroxidase distinct from the other three known human peroxidases, and was closely related to bLPO. This result confirms the presence of at least one distinct lactoperoxidase in humans.

Mutation analysis of thyroid peroxidase gene in Chinese patients with total iodide organification defect: identification of five novel mutations

“…As shown in Fig. 4A, Ala489, Phe490, Arg491, Gly493, and His494 are well conserved among all known TPO polypeptides, including pig (Magnusson et al 1987b), mouse (Kotani et al 1993), and rat (Derwahl et al 1989), and also in human (Morishita et al 1987) and mouse myeloperoxidases (Venturelli et al 1989), human eosinophil peroxidase (Ten et al 1989), and human and bovine lactoperoxidases (Dull et al 1990). Phe492, although not conserved among all peroxidases, is conservatively substituted with tyrosine residue in human and mouse myeloperoxidase.…”

“…Conserved amino acids are boxed. The numbering of amino acid sequences is adopted from the following references: human TPO, Kimura et al (1987); pig TPO, Magnusson et al (1987b); mouse TPO, Kotani et al (1993); rat TPO, Derwahl et al (1989); human MPO, Morishita et al (1987); mouse MPO, Venturelli et al (1989); human eosinophil peroxidase (EPO), Ten et al (1989); human and bovine lactoperoxidase (LPO), Dull et al (1990).…”

Casocidin‐I: a casein‐αs2 derived peptide exhibits antibacterial activity

“…Breastfed sucklings, for example, almost exclusively exhibit Bifidobacterium bifidum in their intestine [2]. Milk proteins which are supposed to be responsible for this modulation are for example lysozyme [3,4], lactoperoxidase [5][6][7], lactoferrin [7][8][9] and antibodies [10]. However, in vivo the ingestion of lactoferrin has only a marginal influence on the intestinal microflora [1 1].…”

Expression and characterization of bovine lactoperoxidase by recombinant vaccinia virus

“…Therefore, the glycosylation level of recombinant protein might also be different between RK13 cells and insect cells. Most of the bLPO extracted from milk showed Asp-101 as the N-terminal amino acid residue (Dull et al 1990;Watanabe et al 2000). However, Watanabe et al (2000) found also that different preparations of bLPO showed a different N-terminal amino acid residue.…”