Abstract
Rat basophilic leukemia cells exhibit 12-lipoxygenase activity only upon cell disruption. 12-Lipoxygenase may also possess 15-lipoxygenase activity, as is indicated by the formation of low amounts of 15(S)-HETE, in addition to the predominant product 12(S)-HETE, upon incubation of partially purified 12-lipoxygenase with arachidonic acid. With 5(S)-HPETE as substrate not only 5(S), 12(S)-diHETE and 5(S), 15(S)-diHETE are formed, but also LTA4, as was indicated by the presence of LTA4-derived LTB4-isomers. 12-Lipoxygenase from rat basophilic leukemia cells has many features in common with 12-lipoxygenase from bovine leukocytes. As was suggested for the latter enzyme, 12-lipoxygenase from rat basophilic leukemia cells may represent the remaining LTA4-synthase activity of 5-lipoxygenase, of which the 5-dioxygenase activity has disappeared upon cell disruption. Such a possible shift from 5-lipoxygenase activity to 12-lipoxygenase activity could not simply be induced by interaction of cytosolic 5-lipoxygenase with a membrane fraction after cell disruption, but may involve release of membrane-associated 5-lipoxygenase upon disruption of activated rat basophilic leukemia cells.
| Original language | English |
|---|---|
| Pages (from-to) | 14-25 |
| Number of pages | 12 |
| Journal | Biochimica et Biophysica Acta - Lipids and Lipid Metabolism |
| Volume | 1128 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 13 Jul 1992 |
Keywords
- 12-Lipoxygenase
- 15-Lipoxygenase
- Inverted binding
- Leukotriene A4-synthase
- Rat basophilic leukemia cell
- arachidonate 12 lipoxygenase
- arachidonate 15 lipoxygenase
- arachidonate 5 lipoxygenase
- animal cell
- article
- enzyme activity
- leukemia cell
- nonhuman
- priority journal
- rat