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The lipid body lipoxygenase from cucumber seedlings exhibits unusual reaction specificity
Author(s) -
Feussner Ivo,
Kühn Hartmut
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)00531-d
Subject(s) - lipoxygenase , arachidonic acid , enzyme , chemistry , biochemistry , biosynthesis
The lipid body lipoxygenase of cucumber seedlings is at a high level expressed during the germinating process which is the stage of triglyceride mobilisation. This enzyme exhibits an unusual positional specificity which has not been described so far for any plant and animal lipoxygenase. The purified enzyme converts arachidonic acid to 15‐S‐hydroperoxy‐5Z,8Z,11Z, 13E‐eicosatetraenoic acid (15S‐HPETE), 12‐S‐hydroperoxy‐5Z, 8Z, 10E, 14Z‐eicosatetraenoic acid (12S‐HPETE), and 8‐S‐hydroperoxy‐5Z,9E,11Z,14Z‐eicosatetraenoic acid (8S‐HPETE) in a ratio of 76:4:20 with the corresponding R‐isomers being only minor contaminants. Binding to the lipid bodies enhances the arachidonic acid dioxygenase activity more than 4‐times and alters positional specificity of the enzyme in favour of 8‐S‐hydroperoxy‐5Z,9E,11Z,14Z‐eicosatetraenoic acid (8S‐HPETE) formation.