Partitioning of gramicidin A′ between coexisting fluid and gel phopholipid phases

Dibble, Andrew R. G.; Yeager, Mark D.; Feigenson, Gerald W.

doi:10.1016/0005-2736(93)90400-t

Cited by 12 publications

(18 citation statements)

References 24 publications

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“…3, where, even if gel and fluid phases may coexist, the proportion of irreversibly bound protein decreases with the fraction of fluid phase. This is in agreement with the preferential partitioning of gramicidin A' in fluid phospholipid phases coexisting with gel phases (Dibble et al, 1993). The uneven distribution of a transmembrane peptide into different coexisting lipid domains has also been described by Zhang et al (1995).…”

Section: The Insertion Of C!-hemolysin In Lipid Bilayerssupporting

confidence: 86%

“…In this paper, we explore in more detail the influence of some lipid properties on HlyA binding to membranes. The interest of this study goes beyond the mechanism of action of the toxin, because it is one case of the more general, and important, biological problem of protein insertion in membranes (see reviews by Jain and Zakim, 1987;Hannavy et al, 1993;Isenman et al, 1995; see also, to mention but a few examples, Dibble et al, 1993;Sankaram et al, 1994;Pott and Dufourc, 1995;Rytomaa and Kinnunen, 1995).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Reversible adsorption and nonreversible insertion of Escherichia coli alpha-hemolysin into lipid bilayers

Bakás

Ostolaza

Vaz

et al. 1996

Biophysical Journal

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Alpha-Hemolysin is an extracellular protein toxin (107 kDa) produced by some pathogenic strains of Escherichia coli. Although stable in aqueous medium, it can bind to lipid bilayers and produce membrane disruption in model and cell membranes. Previous studies had shown that toxin binding to the bilayer did not always lead to membrane lysis. In this paper, we find that alpha-hemolysin may bind the membranes in at least two ways, a reversible adsorption and an irreversible insertion. Reversibility is detected by the ability of liposome-bound toxin to induce hemolysis of added horse erythrocytes; insertion is accompanied by an increase in the protein intrinsic fluorescence. Toxin insertion does not necessarily lead to membrane lysis. Studies of alpha-hemolysin insertion into bilayers formed from a variety of single phospholipids, or binary mixtures of phospholipids, or of phospholipid and cholesterol, reveal that irreversible insertion is favored by fluid over gel states, by low over high cholesterol concentrations, by disordered liquid phases over gel or ordered liquid phases, and by gel over ordered liquid phases. These results are relevant to the mechanism of action of alpha-hemolysin and provide new insights into the membrane insertion of large proteins.

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Section: The Insertion Of C!-hemolysin In Lipid Bilayerssupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Reversible adsorption and nonreversible insertion of Escherichia coli alpha-hemolysin into lipid bilayers

Bakás

Ostolaza

Vaz

et al. 1996

Biophysical Journal

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“…The requirement of fluid bilayers for insertion is such that, even if gel and fluid phases may coexist, the proportion of irreversibly bound protein decreases with the fluid phase fraction (66). This is in agreement with the preferential partitioning of gramicidin A in fluid phospholipid phases coexisting with gel phases (70). The uneven distribution of a transmembrane peptide into different coexisting lipid domains has also been described by Zhang et al (71).…”

Section: Reversible Adsorption and Nonreversible Insertion Of Hlya Insupporting

confidence: 71%

E. coli <FONT FACE=Symbol>a</FONT>-hemolysin: a membrane-active protein toxin

Goñi

Ostolaza

1998

Braz J Med Biol Res

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Alpha-Hemolysin is synthesized as a 1024-amino acid polypeptide, then intracellularly activated by specific fatty acylation. A second activation step takes place in the extracellular medium through binding of Ca2+ ions. Even in the absence of fatty acids and Ca2+ HlyA is an amphipathic protein, with a tendency to self-aggregation. However, Ca2+-binding appears to expose hydrophobic patches on the protein surface, facilitating both self-aggregation and irreversible insertion into membranes. The protein may somehow bind membranes in the absence of divalent cations, but only when Ca2+ (or Sr2+, or Ba2+) is bound to the toxin in aqueous suspensions, i.e., prior to its interaction with bilayers, can a-hemolysin bind irreversibly model or cell membranes in such a way that the integrity of the membrane barrier is lost, and cell or vesicle leakage ensues. Leakage is not due to the formation of proteinaceous pores, but rather to the transient disruption of the bilayer, due to the protein insertion into the outer membrane monolayer, and subsequent perturbations in the bilayer lateral tension. Protein or glycoprotein receptors for a-hemolysin may exist on the cell surface, but the toxin is also active on pure lipid bilayers

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“…It therefore becomes important to understand how amphiphilic probes are distributed in a membrane if it is heterogeneous. This question has been addressed in the past for several different kinds of amphiphiles by various authors (Sklar et al, 1979;Klausner and Wolf, 1980;Welti and Silbert, 1982;Huang et al, 1988;Tocanne, 1989;Spink et al, 1990;Martin et al, 1990;Dibble et al, 1993;Welti and Glaser, 1994;Feigenson, 1997). However, we are not aware of any study that systematically relates the structural characteristics (aliphatic chain length and degree of saturation) of a homologous series of probes to their partition coefficients between coexisting membrane phases beyond an "order-of-magnitude" estimate.…”

Section: Introductionmentioning

confidence: 97%

Partitioning of Amphiphiles between Coexisting Ordered and Disordered Phases in Two-Phase Lipid Bilayer Membranes

Mesquita

Melo

Thompson

et al. 2000

Biophysical Journal

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The partition coefficients (K(P)) of a series of single-chain and double-chain fluorescent amphiphiles, between solid ordered (P(beta') and L(beta)) and liquid disordered (L(alpha) of the type l(d)) lipid phases coexisting in the same lipid bilayer, was studied using steady-state fluorescence emission anisotropy. The single-chain amphiphiles were N-(7-nitrobenzoxa-2, 3-diazol-4-yl)-alkylamines, and the double-chain amphiphiles were N-(7-nitrobenzoxa-2, 3-diazol-4-yl)-phosphatidylethanolamines with chain lengths of 12-18 carbon atoms. Saturated 18-carbon alkyl/acyl chain compounds were also compared with Delta(9)-cis unsaturated chains of the same chain length. The fluorescence anisotropy of the probes was examined in lipid bilayers (multilamellar vesicles) prepared from an equimolar mixture of dilauroylphosphatidylcholine and distearoylphosphatidylcholine and studied as a function of temperature through the entire temperature range of coexistence of ordered gel phases and a disordered fluid phase in this system. The unsaturated chain amphiphiles partitioned exclusively into the fluid phase whenever this phase was present, as did the saturated chain amphiphiles with the shortest chains (C(12:0)), while K(P) ranges between 1 and 2, in favor of the L(beta) solid phase, for the amphiphiles with long saturated (C(18:0)) alkyl/acyl chains, with intermediate behavior for the intermediate chain lengths. All probes appeared to be totally excluded from P(beta') solid (gel) phases. The technique was also used to determine partitioning of some of the probes between coexisting liquid ordered (cholesterol-containing) (l(o)) and liquid disordered (l(d)) L(alpha) phases. In this case the ratio of signal amplitude to noise allowed us to obtain a qualitative, but not quantitative, measure of the phase partitioning of the probes. We conclude that the partitioning behavior of the probes examined between coexisting l(o) and l(d) phases is qualitatively similar to that observed between solid ordered and liquid disordered phases.

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Partitioning of gramicidin A′ between coexisting fluid and gel phopholipid phases

Cited by 12 publications

References 24 publications

Reversible adsorption and nonreversible insertion of Escherichia coli alpha-hemolysin into lipid bilayers

Reversible adsorption and nonreversible insertion of Escherichia coli alpha-hemolysin into lipid bilayers

E. coli <FONT FACE=Symbol>a</FONT>-hemolysin: a membrane-active protein toxin

Partitioning of Amphiphiles between Coexisting Ordered and Disordered Phases in Two-Phase Lipid Bilayer Membranes

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