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Protection by different agents against inactivation of lipoxygenase by hydrogen peroxide
Author(s) -
PérezGilabert Manuela,
Veldink Gerrit A.,
Vliegenthart Johannes F. G.
Publication year - 1996
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02587908
Subject(s) - chemistry , hydrogen peroxide , lipoxygenase , oleic acid , linoleic acid , stearic acid , enzyme , peroxide , mannitol , biochemistry , organic chemistry , fatty acid
H 2 O 2 is a potent inactivator of lipoxygenase. In his paper, the ability of different agents [mannitol, oleic, stearic and linoleic acid, n ‐butanol, and hydroperoxy octadecadienoic acid (HPOD)] to prevent the inactivation of tomato lipoxygenase by hydrogen peroxide has been studied. The involvement of OH · in the inactivation process is suggested by the ability of mannitol to prevent the loss of activity. This radical would be produced by reaction of H 2 O 2 with the Fe(II) lipoxygenase. The most effective protection was displayed by HPOD, the product of the reaction of lipoxygenase with linoleic acid. This result could be explained by the conversion of the native enzyme into the Fe(III) lipoxygenase in the presence of HPOD; the Fe(III) enzyme is not able to react with H 2 O 2 , and no OH · will be produced. The protective effect obtained with oleic and stearic acid could be explained by an occupation of the active center by these inhibitors. The enzyme would not transform them, but their presence would hamper the conversion of H 2 O 2 in OH · and limit the damage in the active center.