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Fish oil increases mitochondrial phospholipid unsaturation, upregulating reactive oxygen species and apoptosis in rat colonocytes.

We have shown that a combination of fish oil (high in n-3 fatty acids) with the butyrate-producing fiber pectin, upregulates apoptosis in colon cells exposed to the carcinogen azoxymethane, protecting against colon tumor development. We now hypothesize that n-3 fatty acids prime the colonocytes such that butyrate can initiate apoptosis. To test this, 30 Sprague-Dawley rats were provided with diets differing in the fatty acid composition (corn oil, fish oil or a purified fatty acid ethyl ester diet). Intact colon crypts were exposed ex vivo to butyrate, and analyzed for reactive oxygen species (ROS), mitochondrial membrane potential (MMP), translocation of cytochrome C to the cytosol, and caspase-3 activity (early events in apoptosis). The fatty acid composition of the three major mitochondrial phospholipids was also determined, and an unsaturation index calculated. The unsaturation index in cardiolipin was correlated with ROS levels (R = 0.99; P = 0.02). When colon crypts from fish oil and FAEE-fed rats were exposed to butyrate, MMP decreased (P = 0.041); and translocation of cytochrome C to the cytosol (P = 0.037) and caspase-3 activation increased (P = 0.032). The data suggest that fish oil may prime the colonocytes for butyrate-induced apoptosis by enhancing the unsaturation of mitochondrial phospholipids, especially cardiolipin, resulting in an increase in ROS and initiating apoptotic cascade.

Animals↗

p53-defective tumors with a functional apoptosome-mediated pathway: a new therapeutic target.

BACKGROUND: Although cancer cells appear to maintain the machinery for intrinsic apoptosis, defects in the pathway develop during malignant transformation, preventing apoptosis from occurring. How to specifically induce apoptosis in cancer cells remains unclear. METHODS: We determined the apoptosome activity and p53 status of normal human cells and of lung, colon, stomach, brain, and breast cancer cells by measuring cytochrome c-dependent caspase activation and by DNA sequencing, respectively, and we used COMPARE analysis to identify apoptosome-specific agonists. We compared cell death, cytochrome c release, and caspase activation in NCI-H23 (lung cancer), HCT-15 (colon cancer), and SF268 (brain cancer) cells treated with Triacsin c, an inhibitor of acyl-CoA synthetase (ACS), or with vehicle. The cells were mock, transiently, or stably transfected with genes for Triacsin c-resistant ACSL5, dominant negative caspase-9, or apoptotic protease activating factor-1 knockdown. We measured ACS activity and levels of cardiolipin, a mitochondrial phospholipid, in mock and ACSL5-transduced SF268 cells. Nude mice carrying NCI-H23 xenograft tumors (n = 10) were treated with Triacsin c or vehicle, and xenograft tumor growth was assessed. Groups were compared using two-sided Student t tests. RESULTS: Of 21 p53-defective tumor cell lines analyzed, 17 had higher apoptosome activity than did normal cells. Triacsin c selectively induced apoptosome-mediated death in tumor cells (caspase activity of Triacsin c-treated versus untreated SF268 cells; means = 1020% and 100%, respectively; difference = 920%, 95% CI = 900% to 940%; P<.001). Expression of ACSL5 suppressed Triacsin c-induced cytochrome c release and subsequent cell death (cell survival of Triacsin c-treated mock- versus ACSL5-transduced SF268 cells; means = 40% and 83%, respectively; difference = 43%, 95% CI = 39% to 47%; P<.001). ACS was also essential to the maintenance of cardiolipin levels. Finally, Triacsin c suppressed growth of xenograft tumors (relative tumor volume on day 21 of Triacsin c-treated versus untreated mice; means = 4.6 and 9.6, respectively; difference = 5.0, 95% CI = 2.1 to 7.9; P = .006). CONCLUSIONS: Many p53-defective tumors retain activity of the apoptosome, which is therefore a potential target for cancer chemotherapy. Inhibition of ACS may be a novel strategy to induce the death of p53-defective tumor cells.

Animals↗

IgA affinity to ssDNA or endothelial cells and its deposition in glomerular capillary walls in IgA nephropathy.

Autoantibodies to glomerular components may be pathogenetic in IgA nephropathy. We studied sera from 32 IgA nephropathy patients, 35 normal controls and 102 patients controls with other forms of glomerulonephritis for IgA isotype affinity to endothelial cells, denatured DNA (ssDNA), murine laminin, and cardiolipin measured by ELISA. Compared to the normal controls, patients with IgA nephropathy had significantly elevated IgA with affinity to endothelial cells (P = 0.01) and ssDNA (P = 0.04), but not to murine laminin or cardiolipin. Furthermore, serum IgA with affinity to ssDNA, but not to endothelial cells, was associated with the presence of IgA deposited in the glomerular capillary walls (P = 0.011), an indicator of poor prognosis in patients with IgA nephropathy. Therefore, IgA with affinity to ssDNA may represent an autoantibody with pathogenetic significance in IgA nephropathy.

Adult↗

Development of mitochondrial membranes in anaerobically grown yeast cells.

Biochemical analyses of mitochondrial marker substances, especially cardiolipin and oligomycin-sensitive ATPase [EC 3.6.1.3], as well as electron microscopic observations were carried out to eludicate the process of mitochondrial development in annaerobic yeast cells. Cardiolipin was found to be localized in the mitochondria in anaerobic cells. Its cellular content was a little higher in the stationary phase than in the exponential phase in glucose-grown cells and increased further in galactose-grown cells. The lipid content of the mitochondrial preparation obtained from glucose-grown stationary cells was nearly as high as that from galactose-grown cells. It was also comparable to that of aerobic cells in the stationary phase, where mitochondria are fully developed. Both cellular and mitochondrial levels of oligomycin-sensitive ATPase activity were also found to rise markedly in galactose-grown anaerobic cells, although not in stationary phase cells grown anaerobically on glucose. These high levels of the mitochondrial markers indicate a developmental change in mitochondrial structure even in anaerobically grown cells, which lack mitochondrial cytochromes. In the process of aerobic adaptation, respiratory system formation was observed to occur much faster in galactose-grown cells than in glucose-grown cells, and not to be inhibited by chloramphenicol and high concentrations of glucose structure in anaerobic cells. The developmental change was also corroborated by electron microscopic observations, which revealed the occurrence of two types of mitochondria in anaerobic cells. One was found in glucose-repressed cells and was characterized by the presence of numerous electron-dense granules in the matrix. In contrast, the other type, found in glucose-derepressed cells, had an electron-lucent matrix. No crista membrane was seen in either type of mitochondria in anaerobic cells, although the infoldings of the inner membrane, which partition the matrix into two parts and therefore are called "septum membranes," appeared frequently in the stationary phase cells. On the basis of these results, the process of mitochondrial development in yeast cells is discussed.

Adenosine Triphosphatases↗

Novel polar lipid composition of Clostridium innocuum as the basis for an assessment of its taxonomic status.

The extractable polar lipids of Clostridium innocuum have been shown to consist of glycosyldiradylglycerols, phospholipids and phosphoglycolipids. The major glycosyldiradylglycerols are D-Glcp(alpha 1-3)radyl2Gro and D-Galp(alpha 1-2)D-Glcp(alpha 1-3)radyl2Gro. Both glycolipids have some 1-O-(alk-1-enyl)-2-O-acyl species, in addition to diacyl species. The phospholipids include bisphosphatidylglycerol (cardiolipin), lysocardiolipin and phosphatidylglycerol (PG). In addition, several novel lipids have been found, including a PG acetal of cardiolipin plasmalogen, smaller amounts of a lyso form of this lipid, a PG acetal of PG plasmalogen, and two phosphoglycolipids, which represent 65% of total polar lipids. The latter have been identified as 2'-amino-1',3'- dihydroxypropane-3'-P-6-D-Galp(alpha 1-2)D-Glcp(alpha 1-3)radyl2Gro and a derivative of this lipid containing an acyl chain esterified to O-6 of the glucopyranosyl ring. Based on rRNA sequence data, C. innocuum is considered to be a relative of the mycoplasmas. Its unique lipid composition permits an assessment of the taxonomic status of C. innocuum, since the lipid amphiphiles display marked differences from those of Acholeplasma laidlawii.

Carbohydrate Sequence↗

Lipid composition of Staphylococcus aureus and its derived L-forms.

Two strains of Staphylococcus aureus (Newman and Tazaki) and their derived L-forms were cultured in serum-containing broth and the differences in their lipid compositions were analyzed. Cardiolipin accounted for more than 50% of the total phospholipid phosphorus in L-forms, but for less than 25% in parent bacteria. The cardiolipin content of L-forms was very high through all growth phases, although it increased gradually as growth proceeded. Significant amounts of cholesterol and its esters were present in parent strains and L-forms, all of which incorporated serum cholesterol into the cell membrane. On the other hand, they could be detected in the L-forms but not in the parent strains when they were cultured in serum-free broth. To examine the ability of L-forms to synthesize cholesterol, the cholesterol content of L-forms cultured in serum-free broth was compared with that of the medium. The results indicated that staphylococcal L-forms could synthesize cholesterol and its esters. These differences in lipid composition suggested that modification of membrane lipids may occur as an adaptational change in response to the disappearance of the cell wall.

Cardiolipins↗

Detection of endothelial cell-reactive immunoglobulin in patients with anti-phospholipid antibodies.

Individuals with anti-phospholipid antibodies are at increased risk for the development of thrombosis and fetal loss. The pathogenesis of these syndromes is unknown, but may involve antibody-mediated alterations in endothelial cell coagulant activity. To address this possibility, we determined the incidence of endothelial cell-reactive antibodies in 76 patients whose plasma contained anti-phospholipid antibodies, but who had no clinically-evident immune disorder. Plasma from 47 patients deposited significantly more immunoglobulin on cultured endothelial cells than control plasma. Positive tests were more frequent in patients with a history of thrombosis than in those without (17/19 v 23/48; P = 0.004). However, we observed no correlation between immunoglobulin deposition on cardiolipin and endothelial cells by individual plasmas. Furthermore, endothelial cell reactivity was not diminished by adsorption of anti-cardiolipin antibodies from patient sera using liposomes. Immunoglobulin fractions prepared from 5/6 patient sera immunoprecipitated a approximately 70 kDa endothelial cell surface protein; 4/5 of these fractions also induced the release of von Willebrand factor from endothelial cells. These results demonstrate that plasma from many patients with anti-phospholipid antibodies, but no clinically-evident autoimmune disease, also contains endothelial cell-reactive antibodies. Detection of such antibodies might help identify individuals in this patient population at greatest risk for thrombosis.

Antibodies↗

Enhanced synthesis of cytokines by peripheral blood monocytes cultured in the presence of autoantibodies against U1-ribonucleoprotein and/or negatively charged molecules: implication in the pathogenesis of pulmonary hypertension in mixed connective tissue disease (MCTD).

An attempt was made to determine whether addition of purified autoantibodies against U1-ribonucleoprotein (RNP) and negatively charged molecules (cardiolipin and double-stranded (ds) DNA) to cultures of peripheral blood monocytes could enhance the synthesis of cytokines in patients with MCTD and normal healthy volunteers. It was found that: (i) at the baseline, levels of cytokines such as IL-1 alpha, IL-1 beta and IL-6 extracellularly released by or associated with monocytes were significantly higher in MCTD patients than in normal subjects; (ii) addition of antibodies against U1-RNP to cultures of MCTD monocytes resulted in a significant overall increase of the released and cell-associated IL-1 alpha, IL-1 beta and IL-6. On the other hand, addition of antibodies against cardiolipin or dsDNA to cultures of MCTD monocytes resulted in a significant increase of released and/or cell-associated IL-1 alpha and IL-1 beta; (iii) addition of these autoantibodies to cultures of normal monocytes resulted in a significant overall increase of released and cell-associated IL-1 alpha, IL-1 beta and IL-6. The extent of enhancement of cytokines released by or associated with monocytes was greater in normal subjects than in MCTD patients; (iv) a F(ab')2 preparation of autoantibodies against U1-RNP also enhanced the level of released and cell-associated IL-1 alpha. Our findings that both autoantibodies against U1-RNP and negatively charged molecules were able to enhance the synthesis of cytokines by monocytes suggest that these autoantibodies might cause derangement of endothelial cells and lead to proliferative vasculopathy, which is a characteristic of pulmonary hypertension in MCTD.

Autoantibodies↗

Subclasses of IgG anticardiolipin antibodies in patients with systemic lupus erythematosus.

Antibodies directed to a co-factor associated with negatively charged phospholipids, such as cardiolipin, occur in patients with systemic lupus erythematosus (SLE), and possibly more often in those with venous or arterial thrombosis, thrombocytopenia or recurrent fetal loss. They are also found in patients without any of these manifestations and their biological effect, if any, might thus be related to their IgG subclass. To investigate this possibility, we determined anticardiolipin antibodies (ACA) by enzyme immunoassay (EIA) using monoclonal antibodies (MoAb) against human IgG subclasses. A net absorbance of x +3 SD of the value of 30 blood donors was taken as the cut-off point. The specificity of the assay was verified through inhibition experiments using cardiolipin micelles. Thirty-three patients with SLE were studied, all of whom had been shown to have ACA by a point dilution screening assay. IgG1 ACA were found in 85% of the patients, and ACA of the IgG2, IgG3 and IgG4 subclasses in 42%, 39% and 15%. There was a significant correlation between the presence of IgG3 ACA and of anti-DNA antibodies but none between subclass distribution and major clinical manifestations of SLE.

Antibodies↗

Induction of tolerance to experimental anti-phospholipid syndrome (APS) by syngeneic bone marrow cell transplantation.

Previously, we have shown the ability to induce experimental autoimmune conditions (e.g. SLE, APLS, Wegener's granulomatosis) following active immunization with the pathogenic autoantibody emulsified in adjuvant. The mice first develop anti-autoantibodies (Ab2: anti-id) and eventually generate anti-anti-autoantibodies (Ab3: anti-anti-id) which carry the same antigen binding characteristic as the autoantibody (Ab1). The appearance of the specific autoantibodies in mice sera was associated with the emergence of the compatible laboratory and with the clinical findings characteristic to the respective autoimmune disease. The effects of syngeneic bone marrow transplantation (BMT) on experimental anti-phospholipid syndrome (APS) were investigated. BALB/c mice were immunized with anti-cardiolipin monoclonal antibody (MoAb) named CAM and developed elevated serum titres of anti-phospholipid Abs accompanied by prolonged activated partial thromboplastin time, thrombocytopenia and a high percentage of fetal resorptions. These mice were then lethally irradiated and transfused with bone marrow (BM) cells (T cell depleted) from syngeneic naive mice. The titres of antiphospholipid antibodies were reduced in the recipients. The decrease in titre of autoantibodies was found to be related to depletion of antibody forming cells in vivo, associated with reduced proliferative response of lymph node cells to anti-cardiolipin MoAbs. The recipients showed improvement in clinical parameters following syngeneic BMT. The same recipients developed specific unresponsiveness to a second challenge with the anticardiolipin MoAb (CAM), but developed experimental systemic lupus erythematosus upon immunization with a monoclonal anti-DNA antibody. We conclude that acute myeloablative immunosuppression combined with syngeneic bone marrow transplantation may induce a state of tolerance to the pathogenic autoantibodies in mice with experimental APLS. Our results suggest that a similar approach may be useful in treating life-threatening autoimmune syndromes (e.g. catastrophic APLS) in clinical practice.

Animals↗

The interaction of phospholipid membranes and detergents with glutamate dehydrogenase.

1. Both the anionic detergent sodium dodecylsulphate and the cationic detergent cetyltrimethylammonium bromide quenched the protein fluorescence of glutamate dehydrogenase. The anionic compound was more effective and brought about 50% quenching at a detergent concentration of 0.4 mM. The zwitterionic amphiphile, lysolecithin, did not quench the protein fluorescence and neither did the short-chain detergent n-hexylsulphonate, which under the range of concentrations examined (less than 1 mM) does not form micelles. 2. The zwitterionic phospholipid, phosphatidylcholine, did not quench the protein fluorescence but the anionic phospholipids, phosphatidylserine and cardiolipin, induced a reversible quenching of the enzyme fluorescence. These observations confirm the specificity of the phospholipid-enzyme interactions as deduced from the kinetic studies of the preceding paper. The degree of quenching brought about by the phospholipids decreased with increasing ionic strength and increasing pH and could be substantially reduced by basic proteins. An electrostatic contribution to the interaction is inferred from these results. 3. The binding of the anionic phospholipids to the enzyme is manifested in a further enhancement of the fluorescence of a 1-anilinonaphthalene-8-sulphonate-enzyme complex. The presence of substrates and allosteric effectors affect the interaction of the lipids with the enzyme as indicated by the magnitude of this increase in fluorescence. The enhancement of fluorescence of NADH when bound to the enzyme was not affected by the binding of the lipids. 4. The complex formed between the enzyme and phosphatidylserine/phosphatidylcholine can be solubilized in isooctane. The photolability of the aqueous protein when subjected to irradiation at 280 nm is suppressed in the isooctane-soluble complex. 5. Phosphatidylserine brings about a rapid (t 1/2 is about 150 ms at a lipid concentration of 0.75 mM) dissociation of the linear aggregates formed between the enzyme oligomers. 6. A model of the enzyme-lipid-membrane complex, consistent with these results, is proposed. It is suggested that the enzyme is an allotopic protein and that the dissociation of the enzyme in vitro may involve binding sites on the protein which are designed for interaction with the cardiolipin of the inner mitochondrial membrane, when the enzyme is in the mitochondrial matrix.

Ammonium Chloride↗

Reconstitution of the isolated phosphate-transport system of pig-heart mitochondria.

The phosphate carrier of pig heart mitochondria has been isolated and reconstituted in liposomes. The highest specific activity for [32P]phosphate exchange was obtained with hydroxyapatite eluate from mitochondria, extracted with Triton X-114 in the presence of cardiolipin. This fraction, which is free from the ADP ATP-carrier, had a specific activity of 30 mumol 32Pi x min-1 x mg protein -1. The following conditions were found to inactivate the phosphate carrier irreversibly in the solubilized state: high ionic strength, high detergent concentrations and a high pH. The decrease of the activity by high detergent concentrations can be largely prevented by cardiolipin, present in the extraction buffer, suggesting a specific removal of this lipid by the detergent. After reconstitution in liposomes, the phosphate carrier is rather stable. The Arrhenius plot of the temperature-dependence of the reconstituted phosphate exchange showed different slopes above and below 27 degrees C. Between 0 degrees C and 27 degrees C the EA was 64 kJ . mol-1, between 27 degrees C and 42 degrees C 44 kJ . mol-1. The exchange of Pi followed a first-order kinetic.

Animals↗

Enhancement of 45Ca2+ binding to acidic lipids by barbiturates, diphenylhydantoin, and ethanol.

Effects of barbiturates, diphenylhydantoin, and ethanol on 45Ca2+ binding to acidic lipids have been examined in an organic, solvent-aqueous partition system. Hexobarbital, pentobarbital, and phenobarbital, at concentrations of 0.3 and/or 0.6 mM, enhanced the binding of 45Ca2+ to phosphatidic acid, phosphatidylserine, and sulfatide but not to phosphatidylinositol or cardiolipin. Diphenylhydantoin, 0.3 mM, enhanced 45Ca2+ binding to phosphatidic acid and phosphatidylserine but not to sulfatide. Ethanol at 80 mM did not enhance 45Ca2+ binding to phosphatidic acid, but ethanol decreased the binding to cardiolipin and increased it to sulfatide.

Barbiturates↗

Nisin resistance in Listeria monocytogenes ATCC 700302 is a complex phenotype.

Nisin resistance in Listeria monocytogenes ATCC 700302 is a complex phenotype involving alterations in both the cytoplasmic membrane and the cell wall and a requirement for divalent cations. In addition to a lower ratio of C15 to C17 fatty acids than in the wild-type strain (A. S. Mazzotta and T.J. Montville, J. Appl. Microbiol. 82: 32-38, 1997), this nisin-resistant (Nisr) strain contained significantly more zwitterionic phosphatidylethanolamine and less anionic phosphatidylglycerol and cardiolipin. The extraction of cardiolipin was enhanced by a penicillin-lysozyme step to disrupt the cell wall. This study is the first to quantify the phosphatidylethanolamine component of the L. monocytogenes cytoplasmic membrane. While these cytoplasmic membrane changes were induced by nisin, the Nisr strain also showed altered sensitivities to cell wall-acting compounds, even when grown in the absence of nisin, suggesting a constitutive alteration in the strain's cell wall. A model which integrates the roles of the cell membrane, cell wall, and divalent cations is presented. Finally, nisin resistance in L. monocytogenes ATCC 700302 conferred cross-resistance to the class IIa bacteriocin pediocin PA-1 and the class IV leuconocin S.

Anti-Bacterial Agents↗

Action of phospholipase A 2 and phospholipase C on Bacillus subtilis protoplasts.

Protoplasts prepared from Bacillus subtilis by lysozyme digestion lysed in the presence of pure pancreatic phospholipase A(2). The phospholipids cardiolipin, phosphatidylethanolamine, phosphatidylglycerol and lysylphosphatidylglycerol, which are present in the membrane, are degraded by phospholipase A(2) only after removal of the cell wall, giving free fatty acids and lyso derivatives. The four phospholipids are hydrolyzed equally well at a given enzyme concentration. Differences in the phospholipid composition of the protoplasts were obtained by variations in the growth medium, time of harvesting, and preincubation time with lysozyme. The extent of hydrolysis appeared to depend on the initial phospholipid composition. A relative increase in acidic phospholipids in the membrane facilitated the action of phospholipase A(2), whereas the rate of hydrolysis was diminished when protoplasts were tested which contained a relatively high amount of positively charged phospholipid. Pure phospholipase C from B. cereus preferentially hydrolyzed phosphatidyl-ethanolamine in the B. subtilis membrane. More than 80% of this phospholipid was converted into diglyceride, whereas only 30% of the cardiolipin was hydrolyzed. Such a loss of phospholipids, however, was not followed by lysis of the protoplasts. Liposomes were prepared from the lipid extracts of B. subtilis and incubated with both phospholipases. The hydrolysis pattern of the phospholipids in these model membrane systems was identical to the hydrolysis pattern of the phospholipids in the protoplast membrane. Phospholipase A(2) hydrolyzed all the phospholipids in the liposomes equally well, whereas phospholipase C preferentially degraded phosphatidylethanolamine.

Animals↗

Effect of inhibition of protein synthesis on lipid metabolism in Lactobacillus plantarum.

In Lactobacillus plantarum 17-5, lipid synthesis appears to be correlated with protein synthesis. Inhibition of protein synthesis by chloramphenicol (50 mug/ml) caused the nearly simultaneous inhibition of incorporation of radioactive oleic acid into polar lipids before the cessation of growth. In addition, de novo fatty acid synthesis, as determined by the incorporation of radioactive acetate into cellular lipids, was also inhibited. Removal of the antibiotic resulted in the resumption of growth, protein synthesis, and polar lipid synthesis. Inhibition of protein synthesis by leucine deprivation also produced a marked reduction in the incorporation of radioactive oleic acid into the total polar lipids at about the same time that growth stopped (30 to 60 min after the removal of leucine). However, the different classes of lipids behaved differently. For example, the incorporation of oleic acid into cardiolipin was inhibited immediately upon removal of leucine from the cultures, whereas incorporation into phosphatidyl-glycerol was maintained at near normal rates for 60 min after the removal of leucine and then ceased. In contrast, the accumulation of radioactive oleic acid in a neutral lipid identified as diglyceride occurred to a much greater extent in leucine-deprived cultures than in control (+ leucine) cultures. Upon addition of leucine to leucine-deprived cultures, the rates of synthesis of phosphatidyl-glycerol and cardiolipin returned to normal; the amount of radioactivity in the diglyceride fraction decreased to normal levels concomitantly with increased phospholipid synthesis.

Bacterial Proteins↗

Phospholipase D activity of gram-negative bacteria.

A phospholipase hydrolyzing cardiolipin to phosphatidic acid and phosphatidyl glycerol was characterized in gram-negative bacteria but was absent in preparations of gram-positive bacteria, Saccharomyces cerevisiae, and rat liver mitochondria. In cell-free extracts of Escherichia coli, Salmonella typhimurium, Proteus vulgaris, and Pseudomonase aeruginosa, this cardiolipin-hydrolyzing enzyme had similar pH and Mg2+ requirements and displayed a specificity which excluded phosphatidyl glycerol and phosphatidyl ethanolamine as substrates.

Animals↗

Phospholipid composition of methane-utilizing bacteria.

The phospholipids of Methylococcus capsulatus, Methylosinus trichosporium, La Paz, and OBT were examined in relation to their qualitative and quantitative composition. M. capsulatus exhibited a phospholipid composition consisting of phosphatidylethanolamine, phosphatidylglycerol, cardiolipin, and phosphatidyl-choline. The esterified fatty acids were predominantly C16:0 and C16:1. M. trichosporium, La Paz, and OBT exhibited an essentially identical phospholipid composition consisting of phosphatidylmonomethylethanolamine, phosphatidyl-dimethylethanolamine, phosphatidylcholine, and phosphatidylglycerol. Only trace amounts (less than 1%) of cardiolipin were found in these organisms. The major esterified fatty acid in these organisms was C18:1 (87 to 90%). The monounsaturated fatty acids from all four organisms consisted of both cis and trans isomers, each of which contained delta8, delta9, delta10, and delta11 double-bond positional isomers.

Cardiolipins↗