Arachidonate 15-lipoxygenase (omega-6 lipoxygenase) from human leukocytes. Purification and structural homology to other mammalian lipoxygenases

J Biol Chem. 1988 Apr 15;263(11):5328-32.

Abstract

The enzyme responsible for 15-lipoxygenation of arachidonic acid was purified to homogeneity from human eosinophil-enriched leukocytes using a combination of ammonium sulfate precipitation, hydrophobic interaction chromatography, and high pressure liquid chromatography on hydroxyapatite and cation-exchange columns. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified protein revealed a single major band (apparent Mr 70,000). Amino acid sequence analysis yielded a single N-terminal sequence. Comparison of the N-terminal 15 residues reveals 71% sequence identity to the rabbit reticulocyte lipoxygenase and 36% sequence identity to the rat basophilic leukemia 5-lipoxygenase. In contrast, sequence identity to the soybean lipoxygenase-1 is not observed. These results demonstrate that human 15-lipoxygenase can be isolated from eosinophil-enriched leukocytes and is accessible for direct sequence analysis. Furthermore, we present initial evidence that the mammalian lipoxygenases constitute an homologous family of enzymes. The availability of homogeneous human 15-lipoxygenase will play a key role in elucidating other relationships in this family of enzymes.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Arachidonate 15-Lipoxygenase / blood*
  • Arachidonate 15-Lipoxygenase / isolation & purification
  • Arachidonate Lipoxygenases / blood*
  • Electrophoresis, Polyacrylamide Gel
  • Humans
  • Leukocytes / enzymology*
  • Molecular Weight
  • Rabbits
  • Rats
  • Sequence Homology, Nucleic Acid

Substances

  • Arachidonate Lipoxygenases
  • Arachidonate 15-Lipoxygenase