Lipoxygenases (LOXs) represent a widely distributed family of non-heme, non-sulfur iron-containing dioxygenases that catalyse the regioselective and stereoselective dioxygenation of fatty acid substrates containing one or more (Z,Z)-1,4-pentadiene moieties. Mammalian LOXs are categorized according to the positional specificity of oxygen insertion into arachidonic acid. Four positional LOX isoforms have been identified in mammalian tissues, including the 5S-, 8S-, 12S-, and 15S-LOX, which insert oxygen to yield the corresponding S-enantiomeric hydroperoxy eicosatetraenoic acids (HPETE) as primary products. An even larger diversity of LOX was found to be due to the existence of isozymes with identical positional specificity such as the leukocyte-type (l), platelet-type(p)and epidermal(e)12S-LOX. An additional complexity is introduced by the identification of a new mammalian LOX generating products with R-chirality.
KeywordsFatty Acid Substrate Unique Structural Feature Methyl Arachidonate Amino Acid Segment Oxygen Insertion
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