Premium
Optimization of enzymatic assay for the measurement of lipoxygenase activity in organic solvent media
Author(s) -
Vega Mireille,
Karboune Salwa,
Husson Florence,
Kermasha Selim
Publication year - 2005
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-005-1149-3
Subject(s) - chemistry , cumene hydroperoxide , solvent , xylenol orange , lipoxygenase , chromatography , ferrous , reagent , benzidine , cumene , perchloric acid , methanol , enzyme , nuclear chemistry , organic chemistry , catalysis
Lipoxygenases (LOX; EC 1.13.11.12) are an important class of non‐heme iron enzymes that catalyze the di‐oxidation of PUFA to hydroperoxy FA, which can be measured by the xylenol orange method (FOX). To determine the enzymatic production of these FA in organic solvent media, the FOX assay was optimized using the standard cumene hydroperoxide. An increase in the proportion of methanol from 0 to 75% in the FOX reagent resulted in a 93% increase in the molar absorption coefficients at 560 nm. In addition, the presence of linoleic acid in the cumene hydroperoxide sample enhanced the formation of the FOX complex, resulting in a 50% increase in the sensitivity of the method. Moreover, when perchloric acid was used, the source of ferrous ions and presence of denatured LOX had little effect on the sensitivity of the FOX assay whereas sensitivity decreased by 40–46% with sulfuric acid. The overall results demonstrated that the modified FOX assay may be used for the precise and accurate measurement of hydroperoxy FA obtained by LOX activity in organic solvent media.