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Positional distribution of fatty acids in cardiolipin of mitochondria from 21‐day‐old rats
Author(s) -
Wolff Robert L.,
Combe Nicole A.,
Entressangles Bernard
Publication year - 1985
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/bf02534776
Subject(s) - cardiolipin , cardiolipins , chemistry , linoleic acid , fatty acid , oleic acid , biochemistry , stearic acid , myristic acid , polyunsaturated fatty acid , palmitic acid , chromatography , phospholipid , organic chemistry , membrane
Pure cardiolipins (1,3‐diphosphatidylglycerol) were prepared from mitochondria of heart, liver and kidney from 21‐day‐old male Wistar rats and submitted to Naja naja venom phospholipase A 2 (EC 3.1.1.4) action. Incubation conditions were controlled carefully, and a complete hydrolysis of cardiolipin to lysocardiolipin {di [1 (1″) acyl sn ‐glycero‐3‐phosphoryl] 1′, 3′‐ sn ‐glycerol} and fatty acids from positions 2 (2″) was obtained in less than two hr practically without side reactions. Cardiolipins from the three organs contained low levels of saturated fatty acids; stearic acid accounted for 0.4–0.7% and palmitic acid for 1.4–3.5% of total fatty acids. These percentages apparently depended on the organ. In all three cases, linoleic acid was the major component, but its percentage varied from 62–78% of total fatty acids. Acyl chains linked to positions 1 (1″) of all three cardiolipin preparations exhibited a similar pattern; they were composed of linoleic acid for 85–89%. This fatty acid also was the main component esterified at position 2 (2″), but its percentage was much more variable: from 39.8% in heart to 51.2% in kidney and 67.8% in liver mitochondria. The remaining acids comprised octadecenoic and polyunsaturated fatty acids with more than 18 carbon atoms in different proportions. As opposed to other phospholipids, cis ‐vaccenic acid, and not oleic acid, was the main octadecenoic acid present in cardiolipins. Octadecenoic acids were nine‐ to 10‐fold more concentrated at positions 2 (2″) than at positions 1 (1″). The percentage of cis ‐vaccenic acid was four‐ to five‐fold higher than that of oleic acid at positions 2 (2″), whereas oleic acid dominated at positions 1 (1″). From results presented in this study and selected literature data, it may be concluded that fatty acids are asymmetrically distributed in cardiolipins of different origins, with linoleic acid showing a definite preference for position 1 (1″).