Arachidonate 5-Lipoxygenase (ALOX5)

Arachidonate 5-lipoxygenase (ALOX5, also known as 5-LO or 5-LOX) is an enzyme belonging to the lipoxygenase family. It plays a central role in the metabolism of polyunsaturated fatty acids, particularly arachidonic acid, leading to the production of leukotrienes and other bioactive lipid mediators. ALOX5 catalyzes two key steps in leukotriene biosynthesis: oxygenation of arachidonic acid to form 5-hydroperoxyeicosatetraenoic acid (5-HpETE) and conversion of 5-HpETE into leukotriene A4 (LTA4), which can be further metabolized into other leukotrienes such as LTB4, LTC4, LTD4, and LTE4. Leukotriene antagonists targeting this pathway are used clinically for asthma treatment due to their anti-inflammatory effects on airway tissues. There is growing evidence implicating ALOX5 products in atherosclerosis development and possibly tumorigenesis due to their roles in inflammation regulation. The enzyme requires interaction with a cofactor protein called FLAP (five-lipoxygenase activating protein) for full activity; FLAP anchors ALOX5 to membranes and facilitates substrate transfer.

Other names

5-LO5-LOX

Inhibition of leukotriene synthesis