Arachidonate 5-lipoxygenase

Arachidonate 5-lipoxygenase ( 5 -LO) enzyme, the arachidonic acid is oxidized in two steps to leukotriene A4. With this reaction, the biosynthesis of the leukotrienes B4 stable to E4, which act as hormones in mammals begins. In plants, the linoleic acid is oxidized instead of arachidonic acid. Accordingly, 5-LO occurs in mammals and plants. In humans it is found in all tissue types.

The enzyme is one of the lipoxygenases.

The mammalian enzyme required for the FLAP protein ( arachidonate 5-lipoxygenase - activating protein) function. Variants of FLAP and 5-LO are responsible for increased risk of myocardial infarction or stroke, and atherosclerosis in humans. The expression of 5-LO is upregulated in several tumor cell lines and maybe there associated with the formation of new blood vessels. For these reasons, 5-LO is a target for the treatment of cardiovascular disease and cancer.

Catalyzed reactions

O2 ⇒   ⇒ H2O

Arachidonic acid is oxidized to the 5 -HPETE peroxide, which decomposes to the epoxide leukotriene A4.

Human Genome Organisation Euteleostomi Tissue (biology) Digital Object Identifier The FASEB Journal
14904
de