The Mechanism of Detergent Solubilization of Liposomes and Protein-Containing Membranes

Abstract

The present study explores intermediate stages in detergent solubilization of liposomes and Ca2+-ATPase membranes by sodium dodecyl sulfate (SDS) and medium-sized ( approximately C12) nonionic detergents. In all cases detergent partitioning in the membranes precedes cooperative binding and solubilization, which is facilitated by exposure to detergent micelles. Nonionic detergents predominantly interact with the lipid component of Ca2+-ATPase membranes below the CMC (critical micellar concentration), whereas SDS extracts Ca2+-ATPase before solubilization of lipid. At the transition to cooperative binding, n-dodecyl octaethylene glycol monoether (C12E8), Triton X-100, and dodecyldimethylamine oxide induce fusion of small unilamellar liposomes to larger vesicles before solubilization. Solubilization of Ca2+-ATPase membranes is accompanied by membrane fragmentation and aggregation rather than vesicle fusion. Detergents with strongly hydrophilic heads (SDS and beta-D-dodecylmaltoside) only very slowly solubilize liposomal membranes and do not cause liposome fusion. These properties are correlated with a slow bilayer flip-flop. Our data suggest that detergent solubilization proceeds by a combination of 1) a transbilayer attack, following flip-flop of detergent molecules across the lipid bilayer, and 2) extraction of membrane components directly by detergent micelles. The present study should help in the design of efficient solubilization protocols, accomplishing the often delicate balance between preserving functional properties of detergent sensitive membrane proteins and minimizing secondary aggregation and lipid content.

Enhanced cytotoxicity of pentachlorophenol by perfluorooctane sulfonate or perfluorooctanoic acid in HepG2 cells

“…5B). Like anionic detergents such as sodium dodecyl sulfate, they might preferentially bind plasma membrane fractions (Kudo et al, 2007), and interfere with the membrane/protein interfacial interactions by the membrane solubilization even at concentrations below their critical micelle concentrations (Kragh-Hansen et al, 1998;le Maire et al, 2000;Hu et al, 2003;Kadiyala et al, 2010;Otzen, 2011). For comprehensive understanding the disruptive effects of PFOS (or PFOA) on plasma membrane, further investigations are needed.…”

The Kemp elimination in membrane mimetic reaction media. Probing catalytic properties of cationic vesicles formed from a double-tailed amphiphile and linear long-tailed alcohols or alkyl pyranosidesElectronic supplementary information (ESI) available: Further experimental details and figures. See http://www.rsc.org/suppdata/ob/b4/b403237c/

“…[3][4][5] The phase diagram of mixtures of C 18 C 18 + and C 12 Mal is only derived using a few data points, due to the odd behaviour of these detergent/amphiphile mixtures (vide infra). As a result the pattern is not very clear.…”

Unique incorporation behavior of amino acid-type surfactant into phospholipid vesicle membrane

“…In particular, the sugar-type and the oxyethylene-type nonionic surfactants have been widely used for this purpose, and thus the nonionic surfactant-induced transition from phospholipid vesicles to micelles has been well studied [2][3][4][5][6][7][8][9][10][11]. Although studies using anionic [12][13][14][15][16][17], cationic [12,18], and zwitterionic surfactants [19] have also been published, they have received less attention. Since anionic surfactants are used as detergents, the interaction of anionic surfactants with phospholipid vesicles might be a good model for investigating the influence of detergent on skin [17].…”