Influence of Lipid Components of
            <i>Mycoplasma laidlawii</i>
            Membranes on Osmotic Fragility of Cells

Razin, Shmuel; Tourtellotte, Mark E.; McElhaney, Ronald N.; Pollack, Jonathan D.

doi:10.1128/jb.91.2.609-616.1966

Cited by 105 publications

(24 citation statements)

References 28 publications

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“…These results could be explained if cholesterol were to alter the spacing of polar head groups in the bilayer so as to allow solvent to enter the hydrocarbon core. The association of cholesterol with phospholipid acyl side chains is well established (14)(15)(16)(17)(18). It is generally believed, and our fluorescence data are in complete accord, that sterol increases the mobility of rigid side chains, while reducing the mobility of liquid ones (19)(20)(21)(22)(23)(24).…”

Section: Discussionmentioning

confidence: 99%

Correlation of side chain mobility with cholesterol retention by phospholipid vesicles

Jacobsohn¹,

Estahani

Jacobsohn

1986

Lipids

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Multilamellar vesicles were prepared from choline phospholipids with various fattY acyl chains, singly and in mixtures, with and without cholesterol. Mobility of acyl side chains for each type of vesicle was measured by fluorescence polarization with diphenylhexatriene, and the amounts of cholesterol and phospholipid retained by them after extraction with a nonpolar solvent were determined. The data suggest that structures of acyl chains determine the extractability of cholesterol. Phosphatidylcholines with unsaturated or short saturated side chains above transition temperature retain less cholesterol upon extraction with petroleum ether than phosphatidylcholines with saturated side chains below transition temperature. Correlation of cholesterol retention with side chain mobility showed that cholesterol is more easily removed from vesicles with mobile acyl side chains than from vesicles with rigid side chains. The presence of cholesterol also alters extractability of phospholipids from vesicles and suggests that sterol affects the polarity rather than spacing of headgroups on vesicle surfaces.

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Section: Discussionmentioning

confidence: 99%

Correlation of side chain mobility with cholesterol retention by phospholipid vesicles

Jacobsohn¹,

Estahani

Jacobsohn

1986

Lipids

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“…Increasing unsaturation of long-chain fatty acids has been shown to increase permeability in artificial membranes (2). Razin et al (8) found that oleic acid and other unsaturated longchain fatty acids added to the medium (and found to be incorporated into the membrane) increased the resistance of Mycoplasma laidlawii to osmotic lysis. Others have shown that the degree of unsaturation of the fatty acids of erythrocytes correlated with the resistance of the red cells to hemolysis (10).…”

Section: Discussionmentioning

confidence: 99%

Fatty Acid Composition of L-Forms of Streptococcus faecalis Cultured at Different Osmolalities

1973

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The fatty acid composition of the membranes of three different penicillin-produced L-forms of Streptococcus faecalis was determined: (i) a stable (nonreverting) L-form (T.8) cultured in brain heart infusion (BHI) with 0.5 M sucrose; (ii) a stable L-form (T581) cultured in BHI without sucrose; and (iii) an unstable L-form (T,) cultured in BHI with 0.5 M sucrose and 1,000 U of penicillin per ml.L-forms were obtained by centrifugation and lysed by washing in 1 mM tris(hydroxymethyl)aminomethane-hydrochloride buffer. The parent S. faecalis was also cultured in BHI and BHI containing 0.5 M sucrose, and washed with buffer. The fatty acid composition of L-forms of S. faecalis cultured in BHI without sucrose (370 mosmol) had higher Ci: l and lower C16 than L-forms cultured in the same media with added 0.5 M sucrose (950 mosmol) in both exponential and stationary cultures. In the stationary phase of growth, C1,, was

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“…(v) The ability to alter the fatty acid composition of membrane polar lipids in a predictable manner by the alkane carbon source employed provides an excellent model system for an investigation of membrane structure-function relationships. Mycoplasma laidlawii B polar lipids respond with predictable pattems to the incorporation of a wide range of added fatty acids (9,20). The microorganism M. cerificans offers an excellent model system for the investigation of structure-function relationships in biological membranes.…”

Section: Discussionmentioning

confidence: 99%

Microbial Assimilation of Hydrocarbons: Cellular Distribution of Fatty Acids

Makula

Finnerty

1972

J Bacteriol

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The distribution of cellular fatty acids in defined lipid classes was analyzed in Micrococcus cerificans after growth on specified hydrocarbons. Neutral lipid, phospholipid, and cell residue fatty acids were qualitatively and quantitatively determined for M. cerificans grown on nutrient broth, tetradecane (C ,,) pentadecane (C ,), hexadecane (C ,), and heptadecane (C 17), respectively. Percentage of total cellular fatty acid localized in defined lipid classes from cells grown on the above growth substrates was (i) neutral lipid-11.8, 1.81, 7.74, 23.1, and 2%; (ii) phospholipid-74.5, 65, 66.43, 62.1, and 86%; (iii) cell residue lipid-13.5, 33.29, 25.82, 14.78, and 11.9%. Phospholipid fatty acid chain length directly reflected the carbon number of the alkane substrate, with 40, 84, 98, and 77% of the fatty acids being 14, 15, 16, and 17 carbons when cells were grown on C14, C15, C1I, and C 7 n-alkanes, respectively. The bound lipids of the cell residue after chloroform-methanol extraction were characterized by 2hydroxydodecanoic and 2-hydroxytetradecanoic acids plus a broad spectrum of fatty acids ranging from CIO to C17 chain length. An increase in total unsaturated fatty acid localized in the phospholipids was noted from cells grown on alkanes greater than 15 carbons long. An extracellular accumulation of free fatty acid (FFA) was demonstrated in hexadecane-grown cultures that was not apparent in non-hydrocarbon-grown cultures. Identification of extracellular FFA demonstrated direct derivation from hexadecane oxidation. Studies supporting inhibition of de novo fatty acid biosynthesis in relationship to extracellular FFA and hexadecane oxidation are described. The ability to alter the fatty acid composition of membrane polar lipids in a predictable manner by the alkane carbon source provides an excellent model system for the investigation of membrane structure-function relationships in M. cerificans. Numerous reviews have appeared summarizing the metabolic products resulting from the growth of microorganisms on diverse hydrocarbons (1,7,10,24). Detailed analyses of cellular fatty acids have established specific structural relationships between the cellular fatty acid composition and the hydrocarbon substrate (12,13). Aliphatic alkanes appear to undergo microbial oxidation by way of an alcohol and an aldehyde, yielding a fatty acid of identical carbon number to the alkane substrate. Studies concerning the assimilatory fate of fatty acids into cellular lipid are rare in the field of microbial hydrocarbon oxidation. This report details the nature and distribution of fatty acids in the cellular lipids of Micrococcus cerificans. A relationship between hydrocarbon oxidation and fatty acid metabolism is supported by experimental data implicating regu-latory properties in the membrane phospholipid fatty acid patterns. A physiological role for free fatty acid (FFA) in the medium is suggested for M. cerificans growing on hydrocarbons.MATERIALS AND METHODS Bacterial strains and culture conditions have been described (9). R...

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Influence of Lipid Components of Mycoplasma laidlawii Membranes on Osmotic Fragility of Cells

Cited by 105 publications

References 28 publications

Correlation of side chain mobility with cholesterol retention by phospholipid vesicles

Correlation of side chain mobility with cholesterol retention by phospholipid vesicles

Fatty Acid Composition of L-Forms of Streptococcus faecalis Cultured at Different Osmolalities

Microbial Assimilation of Hydrocarbons: Cellular Distribution of Fatty Acids

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