Bengal gram lipoxygenase: fluorescence quenching study of the interaction of linoleic acid and 13- and 9-hydroperoxylinoleic acids with the two forms of the enzyme

Borthakur, A. and Rao, A. G. A. and Ramadoss, C. S. (1990) Bengal gram lipoxygenase: fluorescence quenching study of the interaction of linoleic acid and 13- and 9-hydroperoxylinoleic acids with the two forms of the enzyme. Journal of Agricultural and Food Chemistry, 38 (7). 1487-1490, 18 ref..

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Abstract

The intrinsic protein fluorescence of the two forms of lipoxygenases from Bengal gram has been characterized. The fluorescence is dominated by emission from tryptophan residues in a hydrophobic environment. The substrate linoleic acid and the reaction products 13- and 9-hydroperoxylinoleic acids quenched the intrinsic protein fluorescence equally for two forms of the enzyme without lag period. From the fluorescence quenching measurements, the association constant (K) and the free energy change for the interaction have been calculated. The two forms of the enzyme differ in their affinity to the substrate. The ΔG° value for the interaction of substrate/products was calculated to be -5.0 kcal/ mol, suggesting that the interaction is a weak one. Spectroscopic measurements do not indicate a large conformational change in the enzyme due to the binding of these molecules.

Item Type:	Article
Uncontrolled Keywords:	lipoxygenases Bengal gram fluorescence quenching enzyme
Subjects:	500 Natural Sciences and Mathematics > 07 Life Sciences > 03 Biochemistry & Molecular Biology > 07 Enzyme Biochemistry 600 Technology > 08 Food technology > 22 Legumes-Pulses
Divisions:	Dept. of Biochemistry
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	19 Jun 2009 05:04
Last Modified:	28 Dec 2011 09:42
URI:	http://ir.cftri.res.in/id/eprint/3147

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