Ca2+-Induced Phase Separation in the Membrane of Palmitate-Containing Liposomes and Its Possible Relation to Membrane Permeabilization

Агафонов, А. В.; Gritsenko, E. N.; Shlyapnikova, Elena A.; Kharakoz, D. P.; Belosludtseva, Natalia V.; Lezhnev, E. I.; Saris, Nils‐Erik L.; Mironova, Galina D.

doi:10.1007/s00232-007-9005-4

Cited by 26 publications

(7 citation statements)

References 53 publications

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“…In sharp contrast, DPPC LUVs exhibit a dramatic change of [u] with temperature, changing from 0.1 mL/g at 20 C to À0.16 mL/g at 65 C. There is an abrupt biphasic change in [u] [u]-versus-T profile for DPPC (Fig. 2) is similar to that previously reported, which is typical for a pseudo-first-order kind of phase transition (35)(36)(37). Fig.…”

Section: Resultssupporting

confidence: 83%

Compressibilities and Volume Fluctuations of Archaeal Tetraether Liposomes

Chong

Sulc

Winter

2010

Biophysical Journal

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Bipolar tetraether lipids (BTLs) are abundant in crenarchaeota, which thrive in both thermophilic and nonthermophilic environments, with wide-ranging growth temperatures (4-108°C). BTL liposomes can serve as membrane models to explore the role of BTLs in the thermal stability of the plasma membrane of crenarchaeota. In this study, we focus on the liposomes made of the polar lipid fraction E (PLFE). PLFE is one of the main BTLs isolated from the thermoacidophilic crenarchaeon Sulfolobus acidocaldarius. Using molecular acoustics (ultrasound velocimetry and densimetry), pressure perturbation calorimetry, and differential scanning calorimetry, we have determined partial specific adiabatic and isothermal compressibility, their respective compressibility coefficients, partial specific volume, and relative volume fluctuations of PLFE large unilamellar vesicles (LUVs) over a wide range of temperatures (20-85°C). The results are compared with those obtained from liposomes made of dipalmitoyl-L-α-phosphatidylcholine (DPPC), a conventional monopolar diester lipid. We found that, in the entire temperature range examined, compressibilities of PLFE LUVs are low, comparable to those found in gel state of DPPC. Relative volume fluctuations of PLFE LUVs at any given temperature examined are 1.6-2.2 times more damped than those found in DPPC LUVs. Both compressibilities and relative volume fluctuations in PLFE LUVs are much less temperature-sensitive than those in DPPC liposomes. The isothermal compressibility coefficient (β(T)(lipid)) of PLFE LUVs changes from 3.59 × 10(-10) Pa(-1) at 25°C to 4.08 × 10(-10) Pa(-1) at 78°C. Volume fluctuations of PLFE LUVs change only 0.25% from 30°C to 80°C. The highly damped volume fluctuations and their low temperature sensitivity, echo that PLFE liposomes are rigid and tightly packed. To our knowledge, the data provide a deeper understanding of lipid packing in PLFE liposomes than has been previously reported, as well as a molecular explanation for the low solute permeation and limited membrane lateral motion. The obtained results may help to establish new strategies for rational design of stable BTL-based liposomes for drug/vaccine delivery.

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Section: Resultssupporting

confidence: 83%

Compressibilities and Volume Fluctuations of Archaeal Tetraether Liposomes

Chong

Sulc

Winter

2010

Biophysical Journal

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“…Actually, oxidative modification of membrane lipids has been shown to induce phase separation of lipids in vesicles . A similar mechanism based on the coexistence of two lipid phases may be also involved in the process of channel formation induced by the addition of some lipidic components to a membrane, as was recently observed upon the addition of palmitic acid to a membrane in the presence of calcium ions. , …”

Section: Discussionmentioning

confidence: 86%

“…57 A similar mechanism based on the coexistence of two lipid phases may be also involved in the process of channel formation induced by the addition of some lipidic components to a membrane, as was recently observed upon the addition of palmitic acid to a membrane in the presence of calcium ions. 58,59 Alternatively, the photodynamically induced dye leakage from liposomes could be associated with an increase in membrane permeability for dyes which is determined by their lipophilicity (solubility-diffusion mechanism). 60 Actually, membrane permeability essentially depends on lipid composition; that is, it is lowered dramatically upon increasing cholesterol or sphingomyelin content.…”

Section: Discussionmentioning

confidence: 99%

Light-Triggered Liposomal Release: Membrane Permeabilization by Photodynamic Action

et al. 2009

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Photosensitized damage to liposome membranes was studied by using different dye-leakage assays based on fluorescence dequenching of a series of dyes upon their release from liposomes. Irradiation of liposomes with red light in the presence of a photosensitizer, trisulfonated aluminum phthalocyanine (AlPcS(3)), resulted in the pronounced leakage of carboxyfluorescein, but rather weak leakage of sulforhodamine B and almost negligible leakage of calcein from the corresponding dye-loaded liposomes. The same series of selectivity of liposome leakage was obtained with chlorin e6 that appeared to be more potent than AlPcS(3) in bringing about the photosensitized liposome leakage. Electrically neutral zinc phthalocyanine tetrasubstituted with a glycerol moiety (ZnPcGlyc(4)) was less effective than negatively charged AlPcS(3) in provoking the light-induced liposome permeabilization. On the contrary, both ZnPcGlyc(4) and AlPcS(3) were much more effective than chlorin e6 in sensitizing gramicidin channel inactivation in planar bilayer lipid membranes, thus showing that relative photodynamic efficacy of sensitizers can differ substantially for damaging different membrane targets. The photosensitized liposome permeabilization was apparently associated with oxidation of lipid double bonds by singlet oxygen as evidenced by the mandatory presence of unsaturated lipids in the membrane composition for the photosensitized liposome leakage to occur and the sensitivity of the latter to sodium azide. The fluorescence correlation spectroscopy measurements revealed marked permeability of photodynamically induced pores in liposome membranes for such photosensitizer as AlPcS(3).

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“…This seems to be important for the mechanism of lipid pore formation, which has been described in details in our earlier works [11, 12]. …”

Section: Discussionmentioning

confidence: 86%

Effect of surface-potential modulators on the opening of lipid pores in liposomal and mitochondrial inner membranes induced by palmitate and calcium ions

Belosludtsev

Belosludtseva

Агафонов

et al. 2015

Biochimica et Biophysica Acta (BBA) - Biomembranes

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The effect of surface-potential modulators on palmitate/Ca2+-induced formation of lipid pores was studied in liposomal and inner mitochondrial membranes. Pore formation was monitored by sulforhodamine B release from liposomes and swelling of mitochondria. ζ-potential in liposomes was determined from electrophoretic mobility. Replacement of sucrose as the osmotic agent with KCl decreased negative ζ-potential in liposomes and increased resistance of both mitochondria and liposomes to the pore inducers, palmitic acid, and Ca2+. Micromolar Mg2+ also inhibited palmitate/Ca2+-induced permeabilization of liposomes. The rate of palmitate/Ca2+-induced, cyclosporin A-insensitive swelling of mitochondria increased 22% upon increasing pH from 7.0 to 7.8. At below the critical micelle concentration, the cationic detergent cetyltrimethylammonium bromide (10 μM) and the anionic surfactant sodium dodecylsulfate (10–50 μM) made the ζ-potential less and more negative, respectively, and inhibited and stimulated opening of mitochondrial palmitate/Ca2+-induced lipid pores. Taken together, the findings indicate that surface potential regulates palmitate/Ca2+-induced lipid pore opening.

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Ca2+-Induced Phase Separation in the Membrane of Palmitate-Containing Liposomes and Its Possible Relation to Membrane Permeabilization

Cited by 26 publications

References 53 publications

Compressibilities and Volume Fluctuations of Archaeal Tetraether Liposomes

Compressibilities and Volume Fluctuations of Archaeal Tetraether Liposomes

Light-Triggered Liposomal Release: Membrane Permeabilization by Photodynamic Action

Effect of surface-potential modulators on the opening of lipid pores in liposomal and mitochondrial inner membranes induced by palmitate and calcium ions

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