Competition of cations at charged micelle and monolayer interfaces

Rosano, Henri L.; Christodoulou, Aris P; Feinstein, Myron E

doi:10.1016/0021-9797(69)90203-3

Cited by 25 publications

(18 citation statements)

References 11 publications

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“…For instance, the competition of cations for charged fatty-acid monolayer interfaces was studied by Rosano et al [54]. Again, it was observed that Li + is less easily displaced at the interface as the other alkali ions.…”

Section: Micellar and Lamellar Systemsmentioning

confidence: 97%

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Hofmeister series and specific interactions of charged headgroups with aqueous ions

Vlachy

Jagoda‐Cwiklik

Vácha

et al. 2009

Advances in Colloid and Interface Science

406

437

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Section: Micellar and Lamellar Systemsmentioning

confidence: 97%

“…Counter-ion binding to micelles has been studied extensively [27,[52][53][54][55][56][57][58]. Schulz et al [56] reported the selective binding of alkali counterions to anionic SDS surfactant films by ion floating technique.…”

Section: Micellar and Lamellar Systemsmentioning

confidence: 99%

Hofmeister series and specific interactions of charged headgroups with aqueous ions

Vlachy

Jagoda‐Cwiklik

Vácha

et al. 2009

Advances in Colloid and Interface Science

406

437

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“…Electrostatics widens this range because the polyanionic surface sequesters hydrogen ions from the solution. (39). As Smith and Tanford have stated (40), "hydrogen bonds between R-COO-and R-COOH are extraordinarily stable when carboxyl groups are attached to long alkyl chains."…”

mentioning

confidence: 98%

Anionic lipid headgroups as a proton-conducting pathway along the surface of membranes: a hypothesis.

Haines¹

1983

Proc. Natl. Acad. Sci. U.S.A.

219

167

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Evidence has been gathering from several laboratories that protons in proton-pumping membranes move along or within the bilayer rather than exchange with the bulk phase. These experiments are typically conducted on the natural membrane in vivo or in vitro or on fragments of natural membrane. Anionic lipids are present in all proton-pumping membranes. Model studies on the protonation state of the fatty acids of liposomes containing entrapped water show that the bilayers always contain mixtures of protonated and deprotonated carboxylates. Protonated fatty acids form stable acid-anion pairs with deprotonatedfatty acids through unusually strong hydrogen bonds. Such acid-anion dimers have a single negative charge, which is shared by the four negative oxygens of both headgroups. The two pK values of the resulting dimer will be significantly different from the pK of the monomeric species, so that the dimer will be stable over a wide pH range. It is proposed that anionic lipid headgroups in biological membranes share protons as acid-anion dimers and that anionic lipids thus trap and conduct protons along the headgroup domain of bilayers that contain such anionic lipids-. Protons pumped from the other side ofthe membrane may enter and move within the headgroup sheet because the protonation rate of negatively charged proton acceptors is 5 orders of magnitude faster than that of water. Protons trapped in the acidic headgroup sheet need not leave this region in order to be utilized by a responsive proton-translocating pore (a transport protein using the proton gradient). Experiments suggest the proton concentration in the headgroup domain may vary widely and the anionic lipid headgroup sheet may therefore function as a proton buffer. -Due to the Gouy-Chapman-Stern layer at polyanionic surfaces, anionic lipids will also sequester protons from the bulk solution at low and moderate ionic strengths. At high ionic strength metal cations may replace protons sequestered near the headgroups, but these cations cannot substitute for protons in the "proton-conducting pathway," which is based on hydrogen bonding.Recent experiments in several laboratories have suggested that protons that are translocated by proton-pumping membranes, such as those of mitochondria and halobacteria, need not enter the external bulk water phase in order to be utilized by protontransporting proteins ofthe membrane, such as ATP synthetase. Notable among these experiments are -those of Michel and Oesterhelt (1), who made careful measurements of proton-dependent ATP synthesis and pH changes in and near illuminated, Halobacterium halobium cells. They found, that the pH is not lowered in the bulk aqueous phase as the protons pumped.by the purple patches of bacteriorhodopsin are utilized by ATP synthetase, which is not present in the purple patches but is found at some distance in red patches ofthe same plasma membrane. They concluded that.the protons do not pass through the bulk aqueous phase but move very close to the membrane surface. This system is un...

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“…8.2) are stabilized by van der Waal interactions between their hydrocarbon chains and by hydrogen bonds formed between deprotonated and protonated acid molecules (Rosano et al 1969;Haines 1983;Apel et al 2002). For this reason the formation of bilayer vesicles is highly sensitive to pH (see Fig.…”

Section: Stability and Permeability Of Amphiphile Vesiclesmentioning

confidence: 96%

Membrane Self-Assembly Processes: Steps Toward the First Cellular Life

Monnard

Deamer

2010

The Minimal Cell

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This review addresses the question of the origin of life, with emphasis on plausible boundary structures that may have initially provided cellular compartmentation. Some form of compartmentation is a necessary prerequisite for maintaining the integrity of interdependent molecular systems that are associated with metabolism, and for permitting variations required for speciation. The fact that lipid-bilayer membranes define boundaries of all contemporary living cells suggests that protocellular compartments were likely to have required similar, self-assembled boundaries. Amphiphiles such as short-chain fatty acids, which were presumably available on the early Earth, can self-assemble into stable vesicles that encapsulate hydrophilic solutes with catalytic activity. Their suspensions in aqueous media have therefore been used to investigate nutrient uptake across simple membranes and encapsulated catalyzed reactions, both of which would be essential processes in protocellular life forms.

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Competition of cations at charged micelle and monolayer interfaces

Cited by 25 publications

References 11 publications

Hofmeister series and specific interactions of charged headgroups with aqueous ions

Hofmeister series and specific interactions of charged headgroups with aqueous ions

Anionic lipid headgroups as a proton-conducting pathway along the surface of membranes: a hypothesis.

Membrane Self-Assembly Processes: Steps Toward the First Cellular Life

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