Cardiolipin degradation

Two strains of Sphingomonas sp. that could degrade pentachlorophenol maintained their levels of ATP even in the presence of high concentrations of pentachlorophenol. Analysis of the lipids using P NMR showed that this could be attributed to the increased levels of cardiolipin (Lohmeier-Vogel et al. 2001). 

We directed our initial attention to the mitochondrion-specific phospholipid, cardiolipin because it is particularly rich in polyunsaturated fatty acids which are vulnerable to oxidative attack. It seemed reasonable to speculate that mitochondrial cardiolipin may degrade by the enhanced peroxidation reactions during apoptotic cell death,... 

Exposure of cardiolipin to oxygen gas resulted in a substantial loss of the lipid and most of the degradation products were hydroperoxide derivatives. Even though we have not done the comparative experiment, our experience tells us that cardiolipin is more sensitive to oxidative stress than free linoleic acid or trilinolein. Taking into account that mitochondria is the site where reactive oxygen species are often produced, we propose that peroxidation of cardiolipin may easily take place once the intracellular oxidative stress occurs. 

Fragmentation (Sgi) of the vicinal peroxides yields 4-H(P)NE and hydroper-oxy epoxides in a reaction that is similar to the mechanism of styrene/oxygen co-polymerization and subsequent degradation to benzaldehyde and formaldehyde [57,65,66], An equivalent cross-chain mechanism is likely to contribute to the formation of 4-H(P)NE during autoxidation of cardiolipin [67]. 

When rabbits are injected with other animal tissue, the Forssman haptens are produced. These are able to lyse erythrocytes from sheep (Forssman 1911). One of these Forssman haptens is a ceramide linked to galactose and galactosamine (Papirmeister et al. 1955). The structure of these haptens leaves the question open whether they arise from ceramide polyhexosides, e.g. globosides, by degradation. It should be mentioned that the only noncarbohydrate lipid with haptogenic properties is cardiolipin. The question whether this haptogenic property is due to the free OH-group remains to be answered. 

The three principal phospholipids (Figure 1.5) of the plasmic membrane of yeast are phos-phatidylethanolamine (PE), phosphatidylcholine (PC) and phosphatidylinositol (PI) which represent 70-85% of the total. Phosphatidylserine (PS) and diphosphatidylglycerol or cardiolipin (PG) are less prevalent. Free fatty acids and phosphatidic acid are frequently reported in plasmic membrane analysis. They are probably extraction artifacts caused by the activity of certain lipid degradation enzymes. 

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