Plasma membrane fluidity

J.-G. Kuhry, G. Kuportail, C. Bronner, and G. Laustriat, Plasma membrane fluidity measurements on whole living cells by fluorescence anisotropy of trimethylammonium-diphenylhexatriene, Biochim. Biophys. Acta 845, 60-67 (1985). 

The intrinsic plasma membrane fluidity of a series of sarcoma cell lines with various degrees of adriamycin resistance was studied by ESR [91]. The results document a systematic increase in the order parameter, S, as the cells become more and more resistant. At the same time, a parallel increase in the sphingomyelin content was ob-... 

Alexandre, H., Rousseaux, I., Charpentier, C. (1994) Relationship between ethanol tolerance, hpid composition and plasma membrane fluidity in Saccharomyces cerevisiae and Kloeckera apiculata. FEMS Microbiol. Lett., 124, 17-22... 

Gibney MJ, Bolton-Smith C. The effect of a dietary supplement of n-3 polyunsaturated fat on platelet lipid composition, platelet function, and platelet plasma membrane fluidity in healthy volunteers. Br J Nutr 1988 60 5-12. 

Kumar, V., and Misra, U.K., Hepatic plasma membrane fluidity and dietary proteins, Indian J. Biochem. Biophys., 28, 301, 1991. 

Ramirez OT, Mutharasan R. (1990) The role of the plasma membrane fluidity on the shear sensitivity of hyhridomas grown under hydrodynamic stress. Biotechnol. Bioeng., 36 911-920. 

Ramirez OT, Mutharasan R. (1992) Effect of serum on the plasma membrane fluidity of hybridomas an insight into its shear protective mechanisms. Biotechnol. Prog., 8 40-50. 

On exposure of cultured mouse embryo cardiac myocytes to 0.2 mM ONOO", [Ca Ji increased to beyond the systoHc level within 5 min with a concomitant decrease in spontaneous contraction of myocytes followed by complete arrest (Ishida et al. 1996). Addition of a L-type Ca channel blocker or removal of extracellular Ca prevented the ONOO"-induced increase in [Ca " ] , indicating that the increase in [Ca " ] was caused by the enhanced influx of Ca " through the plasma membrane and not by the enhanced release from sarcoplasmic reticulum. Plasma membrane fluidity and concentration of the thiobarbituric acid-reactive substance in the cells remained unchanged under the ONOO" treatment. 

A molecular variation of plasma membrane has been reported by Puccia et al. Reduction of total lipids (XL) content and significant variations of triglyceride (TG) and phospholipids (PL) fractions were observed as a consequence of exposure of C. intestinalis ovaries to TBTCl solutions. In particular, an evident TG decrease and a PL increase were observed, which probably provoked an increment in membrane fluidity, because of the high concentration of long chain fatty acids and, as a consequence, PL. This could be a cell-adaptive standing mechanism toward the pollutants, as observed in Saccharomyces cerevisiae. Also the increase in the content of the polyunsaturated fatty acids (PUPA), important in the synthesis of compounds such as prostaglandin which are present in the ovary in a stress situation, was probably a consequence of a defense mechanism to the stress provoked by the presence of TBTCl. 

A shift in temperature from 38 to 22 °C leads to desaturation of fatty acids in Anabaena variabilis [110], resulting in control of the fluidity of the plasma membrane. Mutants have been isolated in Synechocystis PCC 6803 that were defective in desaturation of fatty acids, and the growth rate of one of these mutants was much lower than that of the wild-type at 22 °C [112]. It turned out that the mutant strain had a mutation in the gene desA, and when the wild-type allele was introduced into the chilling-sensitive cyanobacterium Anacystis nidulans, it resulted in increasing the tolerance of that strain to low temperature [113]. These experiments nicely demonstrate the existence of a mechanism of adaptation to low temperature in a chilling-tolerant cyanobacterium. 

The most common sterol in membranes is cholesterol (Chapter 14), which resides mainly in the plasma membranes of mammalian cells but can also be found in lesser quantities in mitochondria, Golgi complexes, and nuclear membranes. Cholesterol intercalates among the phospholipids of the membrane, with its hydroxyl group at the aqueous interface and the remainder of the molecule within the leaflet. Its effect on the fluidity of membranes is discussed subsequently. 

Bums, C. P., Luttenegger, D. G., Dudley, D. T., Buettner, G. R., and Spector, A. A., 1979, Effect of modification of plasma membrane fatty add composition on fluidity and methotrexate transport in L1210 murine leukemia cells. Cancer Res. 39 1726-1732. 

Membrane fluidity and composition. Oil, administered to male weanling Wistar rats at a dose of 100 g fat/kg diet with 10% of the fat provided as corn oil, produced a 61.5% of lipid that were free to diffuse in the plasma membrane . 

CN203 Clamp, A. G., S. Ladha, D. C. Clark, R. F. Grimble, and E. K. Lund. The influence of dietary lipids on the composition and membrane fluidity of rat hepatocyte plasma membrane. Lipids 1997 32(2) 179-184-... 

Cells regulate the lipid compositions of their plasma membrane so that a reasonable membrane fluidity is main-tained. They do this by controlling fatty acid biosynthesis so as to vary the lengths of the fatty acid chains and the ratio of unsaturated to saturated fatty acids (see chapter 19). If cells are grown at low temperatures, their phospholipids contain more unsaturated fatty acids or fatty acids with shorter chains or both. These adjustments shift the Tm to lower temperatures, with the result that (to the extent that the melting transition is sharp enough to be measureable) the Tm re-... 

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