ALOX15 (also termed arachidonate 15-lipoxygenase, 15-lipoxygenase-1, 15-LO-1, 15-LOX-1) is, like other lipoxygenases, a seminal enzyme in the metabolism of polyunsaturated fatty acids to a wide range of physiologically and pathologically important products. Human ALOX15 was initially named arachidonate 15-lipoxygenase or 15-lipoxygenase, but subsequent studies uncovered a second human enzyme with 15-lipoxygenase activity as well as various non-human mammalian Alox15 enzymes that are closely related to and therefore orthologs of human ALOX15. Many of the latter Alox15 enzymes nonetheless possess predominantly or exclusively 12-lipoxygenase rather than 15-lipoxygenase activity. Consequently, human ALOX15 is now referred to as arachidonate-15-lipoxygenase-1, 15-lipoxygenase-1, 15-LOX-1, 15-LO-1, human 12/15-lipoxygenase, leukocyte-type arachidonate 12-lipoxygenase, or arachidonate omega–6 lipoxygenase. The second discovered human 15-lipoxygenase, a product of the ALOX15B gene, is termed ALOX15B, arachidonate 15-lipoxygenase 2, 15-lipoxygenase-2, 15-LOX-2, 15-LO-2, arachidonate 15-lipoxygenase type II, arachidonate 15-lipoxygenase, second type, and arachidonate 15-lipoxygenase; and mouse, rat, and rabbit rodent orthologs of human ALOX15, which share 74-81% amino acid identity with the human enzyme, are commonly termed Alox15, 12/15-lipoxygenase, 12/15-LOX, or 12/15-LO). Both human ALOX15 and ALOX15B genes are located on chromosome 17; their product proteins have an amino acid sequence identity of only ~38%; they also differ in the polyunsaturated fatty acids that they prefer as substrates and exhibit different product profiles when acting on the same substrates.
