Effect of Ethanol on the Structure and Properties of β-Casein Adsorption Layers at the Air/Buffer Interface

Puff, Nicolas; Cagna, Alain; Aguié‐Béghin, Véronique; Douillard, Roger

doi:10.1006/jcis.1998.5846

Cited by 37 publications

(42 citation statements)

References 41 publications

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“…The surface compression moduli expressed as a function of π are clearly not monotonic, and in the case of c‐Fos it exhibits two maxima (Inset in Figure 3), supporting the concept that the proteins we are dealing with are flexible 48. Moreover, if we assume that, despite the obvious differences between the K vs. π and ε vs. π dependences, the Flory exponent γ taken from the slopes of K vs. π curves relates to the molecular arrangement at the interface,49 the slope values of 5 and 1 for c‐Fos in the lineal region before the first and the second maximum respectively, mean that the surface behavior is dominated by the hydrophobic portions of the protein along the interface at low surface pressure (dilute regime), and by the hydrophilic portions forming a network in the bulk just below the interface at higher pressures (semidilute regime) 49. The fact that Fra‐1 and c‐Jun do not present a second maximum implies that these two proteins do not transition to a network at high packing; this translates in a little cooperative molecular reordering at intermediate surface pressures.…”

Section: Resultsmentioning

confidence: 62%

The immediate‐early oncoproteins Fra‐1, c‐Fos, and c‐Jun have distinguishable surface behavior and interactions with phospholipids

et al. 2009

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This work explores the surface properties of the transcription factor Fra-1 and compares them with those of two other immediate early proteins, c-Fos and c-Jun, to establish generalities and differences in the surface behavior and interaction with phospholipids of this type of proteins. We present several experimental clues of the flexible nature of Fra-1, c-Fos, and c-Jun that support sequence-based predictions of their intrinsical disorder. The values of surface parameters for Fra-1 are similar in general to those of c-Fos and c-Jun. However, we find differences in the interactions of the three proteins with phospholipids. The closely related Fra-1 and c-Fos share affinity for anionic lipids but the former has more affinity for a condensed phase and senses a change in DPPC phase, while the latter has more affinity for an expanded phase. These features are in contrast with our previous finding that c-Jun is not selective for phospholipid polar head group or charge. We show here that at least some immediate early transcription factors can interact with membrane phospholipids in a distinguishable manner, and this shall provide a basis for their potential capacity to regulate membrane-mediated cellular processes.

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Section: Resultsmentioning

confidence: 62%

The immediate‐early oncoproteins Fra‐1, c‐Fos, and c‐Jun have distinguishable surface behavior and interactions with phospholipids

et al. 2009

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“…The study of the rheological parameters of adsorption layers of proteins and synthetic polyelectrolytes, in particular, dilatational characteristics, demonstrates an unusual behavior of the elastic modulus (to be exact, viscoelastic modulus) E defined by the relation (26) (A is the surface area) as depending on the bulk concentration, surface pressure, or protein adsorption [36,[54][55][56][57][58][59][60][61][62][63]. In the Maxwell model, the modulus E is expressed as a complex number comprising real (elasticity) and imaginary (viscosity) components: (27) In the case of diffusion-limited adsorption and in the absence of other relaxation processes in the surface layer, the real and imaginary components of the complex elastic modulus are expressed as functions of the frequency f of the surface perturbations and the surfactant (or protein) concentration as follows [59,61]: (28) where ζ = , E 0 = dΠ/dlnΓ is the limiting high-frequency (Gibbs) elasticity, and ω D = D(dΓ/dc) -2 is the characteristic frequency of the diffusion relaxation.…”

Section: Elastic Modulus and Limiting Elasticity Of A Surface Layermentioning

confidence: 99%

“…Experimental data [36,[54][55][56][57][58][59][60][61] testify that the E value for globular proteins is substantially larger than that for flexible-chain proteins and monotonically increases to a certain limiting value with the surface pressure or adsorption. At the same time, for flexiblechain proteins, E is not only smaller by several times than for globular proteins, but its dependences on the surface pressure or adsorption pass through a maximum.…”

Section: Elastic Modulus and Limiting Elasticity Of A Surface Layermentioning

confidence: 99%

Equilibrium and Dynamic Characteristics of Protein Adsorption Layers at Gas-Liquid Interfaces: Theoretical and Experimental Data

Fainerman

Miller

2005

Colloid J

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Within the framework of a nonideal two-dimensional solution model, equations are derived for the state of a surface layer, adsorption isotherms, and the distribution function of adsorbed protein molecules with respect to their states characterized by different molar surface areas. The derived equations satisfactorily describe the known experimental dependences obtained for equilibrium adsorption layers of some proteins (serum albumin, β -casein, and β -lactoglobulin): the dependences of the surface pressure on concentration and adsorption, the surface layer thickness on adsorption, and the limiting high-frequency elastic modulus of an adsorption layer on the surface pressure. All dependences for a given protein are described by the same set of parameters of the theoretical model. It is shown that the kinetics of protein adsorption studied by dynamic tensiometry, ellipsometry, and the radiotracer technique is consistent with the diffusion model comprising the Ward-Tordai equation and the set of equations describing the equilibrium. The kinetics of protein desorption from the adsorption layer at a liquid-fluid interface is analyzed. The kinetics of β -lactoglobulin desorption is shown to be described by the barrier mechanism.

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“…Surface tension was measured using a pendant drop tensiometer from IT Concept, Longessaigne, France (Labourdenne et al ., 1994; Puff et al ., 1998; Péron et al ., 2000, 2001). An air bubble was formed in the liquid at the tip of the needle of a syringe whose plunger position was driven by a computer.…”

Section: Experimental Samples and Set‐upsmentioning

confidence: 99%

Phase separation in molecular layers of macromolecules at the champagne–air interface

Péron¹,

Meunier²,

Cagna³

et al. 2004

Journal of Microscopy

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SummaryBubble and foam stability, which are essential for the hallmark of champagne, rely on the concentration of amphiphilic macromolecules originating from the grape, which form molecular layers at the interface between champagne and gas. Ellipsometry and Brewster angle microscopy experiments were conducted at the air-champagne interface to analyse the lateral organization of the layers of macromolecules. Several kinds of phase separations -leading in some cases to twodimensional foams -were identified. At the beginning of layer formation, condensed domains develop at the expense of dilute domains. Thereafter, phase separations occur within the condensed domains. These findings may allow advances in the implementation of methods predicting bubble and foam stability of champagnes.

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Effect of Ethanol on the Structure and Properties of β-Casein Adsorption Layers at the Air/Buffer Interface

Cited by 37 publications

References 41 publications

The immediate‐early oncoproteins Fra‐1, c‐Fos, and c‐Jun have distinguishable surface behavior and interactions with phospholipids

The immediate‐early oncoproteins Fra‐1, c‐Fos, and c‐Jun have distinguishable surface behavior and interactions with phospholipids

Equilibrium and Dynamic Characteristics of Protein Adsorption Layers at Gas-Liquid Interfaces: Theoretical and Experimental Data

Phase separation in molecular layers of macromolecules at the champagne–air interface

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