Two types of 15-lipoxygenase (15-LO) have been discovered and characterised, both of which metabolise arachidonic acid (AA) to produce 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE). 15-LO-1 oxygenates AA at both C-15 and C-12, whereas 15-LO-2 exclusively oxygenates C-15 of AA. Human 15-LO-2 has a molecular mass of approximately 76 kDa and exhibits approximately 40% identity to the reticulocyte 15-LO-1.2,3 expression of 15-LO-2 appears to be restricted to prostate, lung, skin, and cornea and may play a role in the normal development of these tissues.

The protein levels and enzymatic activity of 15-LO-2 are both down-regulated in prostate cancer compared with normal and benign prostate tissues, implicating a possible protective role for 15-LO-2 against tumor formation. 15-LO-2 (human recombinant) is expressed and purified from E. coli. The purity was determined using gel electrophoresis followed by coomassie staining. 15-LO-2 specific activity was established using arachidonic acid as the substrate and monitoring diene formation by measuring absorbance 236 nm.