Enzyme inhibition by secondary lipid autoxidation products from fish oil
✍ Scribed by Pia Agerbo; Bo M Jørgensen; Benny Jensen; Torger Børresen; Gunhild Hølmer
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 489 KB
- Volume
- 3
- Category
- Article
- ISSN
- 0955-2863
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✦ Synopsis
A series of secondary lipid autoxidation products (hydrocarbons, alcohols, aldehydes, ketones, and carboxylic acids), which have been found in oxidized fish oil, were tested for a possible effect on the in vitro activity of microsomal glucose 6-phosphatase. It was found that only those compounds that possess a carbon-carbon double bond conjugated to an oxo-group (aldehyde or ketone) exerted an appreciable inhibition. Among the homologous trans-2-alkenals, the inhibitory effect increased with chain lengths from C5 to C9, and trans-2-nonenal was the most potent inhibitor of the compounds tested. This dependence on molecular size is not explainable solely by differences in partition coefficients between the incubation medium and the membrane. It is concluded that the inhibition of microsomal glucose 6phosphatase by secondary autoxidation products requires covalent binding to the enzyme (probably to an SH-group) and, moreover, involves perturbation of the lipid phase of the membrane. The enzyme system may be of use in determining the presence of potentially toxic oxidation products in fish lipids.