Work

Expression of cloned human reticulocyte 15-lipoxygenase and immunological evidence that 15-lipoxygenases of different cell types are related.

Year: 1990

Type: article

Abstract: Cloned 15-lipoxygenase has been expressed for the first time in eukaryotic and prokaryotic cells. Transfection of osteosarcoma cells with a mammalian expression plasmid containing the cDNA for human reticulocyte 15-lipoxygenase resulted in cell lines that were capable of oxidizing body arachidonic acid and linoleic acid. The lipoxygenase metabolites were identified by reverse-phase and straight-phase high pressure liquid chromatography, ultraviolet spectroscopy, and direct mass spectrometry, verifying that the cDNA for 15-lipoxygenase encodes an enzyme with authentic 15-lipoxygenase activity. Incubation of the transformed cells with arachidonic acid generated 15-hydroxyeicosatetraenoic acid (HETE) and 12-HETE in a ratio of 8.6 to 1, demonstrating that 15-lipoxygenase can also perform 12-lipoxygenation. Lesser amounts of 15-keto-ETE, four isomers of 8,15-diHETE, and one isomer of 14,15-diHETE were observed. Incubation with linoleic acid generated predominantly 13-hydroxy linoleic acid. The reaction was inhibited by eicosatetraynoic acid but not by indomethacin. Antibodies to a peptide corresponding to a unique region of the predicted amino acid sequence were generated and shown to react with one major band of 70 kDa on immunoblots of human leukocyte 15-lipoxygenase. To obtain antibodies to the full length enzyme, the cDNA was subcloned into a bacterial expression vector and was expressed as a fusion with the CheY protein. The overexpressed protein was readily purified from bacteria and was shown to be immunoreactive to the peptide-derived antibody. Antibodies raised to this recombinant enzyme did not cross-react with human leukocyte 5-lipoxygenase but did identify 15-lipoxygenase in rabbit reticulocytes, human leukocytes, and tracheal epithelial cells, suggesting that the 15-lipoxygenases from these different cell types are structurally related.

Source: Journal of Biological Chemistry

DOI: 10.1016/s0021-9258(19)34092-x

Authors: E Sigal, D Grunberger, E Highland, C Gross, R A Dixon, C S Craik

Institution: University of California, San Francisco

Language: English

Topic: Eicosanoids and Hypertension Pharmacology

Subfield: Biochemistry

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,430