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. 2009 Feb;157(2):104-12.
doi: 10.1016/j.chemphyslip.2008.11.004. Epub 2008 Nov 24.

Solubilization of lipid bilayers by myristyl sucrose ester: effect of cholesterol and phospholipid head group size

C Toro  1 , S A Sanchez, A Zanocco, E Lemp, E Gratton, G Gunther
Affiliations

Solubilization of lipid bilayers by myristyl sucrose ester: effect of cholesterol and phospholipid head group size

C Toro et al. Chem Phys Lipids. 2009 Feb.

Abstract

The solubilization of biological membranes by detergents has been used as a major method for the isolation and purification of membrane proteins and other constituents. Considerable interest in this field has resulted from the finding that different components can be solubilized selectively. Certain membrane constituents are incorporated into small micelles, whereas others remain in the so-called detergent-resistant membrane domains that are large enough to be separated by centrifugation. The detergent-resistant fractions contain an elevated percentage of cholesterol, and thus its interaction with specific lipids and proteins may be key for membrane organization and regulation of cellular signaling events. This report focuses on the solubilization process induced by the sucrose monoester of myristic acid, beta-D-fructofuranosyl-6-O-myristyl-alpha-D-glucopyranoside (MMS), a nonionic detergent. We studied the effect of the head group and the cholesterol content on the process. 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and dioctadecyl-dimethyl-ammonium chloride (DODAC) vesicles were used, and the solubilization process was followed using Laurdan (6-dodecanoyl-2-dimethylaminonaphthalene) generalized polarization (GP) measurements, carried out in the cuvette and in the 2-photon microscope. Our results indicate that: (i) localization of the MMS moieties in the lipid bilayer depends on the characteristics of the lipid polar head group and influences the solubilization process. (ii) Insertion of cholesterol molecules into the lipid bilayer protects it from solubilizaton and (iii) the microscopic mechanism of solubilization by MMS implies the decrease in size of the individual liposomes.

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Figures

Figure 1
Figure 1
Molecular structure of POPC (A), DODAC (B) and MMS (C).
Figure 2
Figure 2
Emission profile of laurdan from DODAC-15%Chol (A) and POPC- 20%Chol (B): pure vesicles (a), vesicles saturated with MMS (b) and vesicles near the critical point of solubilization with MMS (c).
Figure 3
Figure 3
Solubilization profiles of: DODAC 0.4mM vesicles plotted against MMS DODAC ratio (A) and against its reciprocal (DODAC vs MMS) (B), in this plot the surface saturation point can be observed. And POPC 0.4mM liposomes plotted against MMS concentration (C) and against its reciprocal (D).
Figure 4
Figure 4
Solubilization profile of DODAC (A) and POPC (B) small unilamellar vesicles loaded with 30% of Cholesterol.
Figure 5
Figure 5
Dependence of ΔGPsat, (defined in the main text), against percentage of cholesterol present in the bilayer, for POPC (○) and DODAC (●) vesicles. Intersections correspond to Ctss.
Figure 6
Figure 6
Plot of solubilization and saturation critical concentrations (Ct sol (○,□) and Ct sat (●,□)) against DODAC concentration with MMS employed as surfactant. For (A) pure DODAC vesicles and (B) DODAC-15%Chol vesicles.
Figure 7
Figure 7
Intensity image of POPC GUV after addition of MMS (1µM final concentration), showing the change in size during solubilization process.
Figure 8
Figure 8
Solubilization process of: A POPC GUVs with 0.6 µg/mL of MMS; B DODAC GUVs with 0.6 µg/mL of MMS; C POPC GUVs with 30% of Cholesterol and 12.0 µg/mL of MMS and D DODAC GUVs with 26% of Cholesterol and 12.0 µg/mL of MMS
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References

    1. Ahmed SN, Brown DA, London E. On the Origin of Sphingolipid/Cholesterol Rich Detergent-Insoluble Cell Membranes: Physiological Concentrations of Cholesterol and Sphingolipid Induce Formation of a Detergent-Insoluble, Liquid-Ordered Lipid Phase in Model Membranes. Biochemistry. 1997;36:10944–10953. - PubMed
    1. Almog S, Litman BJ, Wimley W, Cohen J, Wachtel EJ, Barenholz Y, Benshaul A, Lichtenberg D. States of Aggregation and Phase-Transformations in Mixtures of Phosphatidylcholine and Octyl Glucoside. Biochemistry. 1990;29:4582–4592. - PubMed
    1. Angelova MI, Dimitrov DS. Liposome Electroformation. Faraday Discussion. Chem. Soc. 1986;81:303–311.
    1. Becerra N, de la Nuez LR, Zanocco AL, Lemp E, Gunther G. Solubilization of dodac small unilamellar vesicles by sucrose esters - A fluorescence study. Colloid Surface A. 2006;272:2–7.
    1. Brown DA, Rose JK. Sorting of GPI-anchored proteins to glycolipid-enriched membrane subdomains during transport to the apical cell-surface. Cell. 1992;68:533–544. - PubMed

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