Specific Ion Effects of Trivalent Cations on the Structure and Charging State of β-Lactoglobulin Adsorption Layers

Richert, Manuela; Gochev, Georgi; Braunschweig, Björn

doi:10.1021/acs.langmuir.9b01803

Cited by 23 publications

(16 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This effect has been previously observed in several systems undergoing charge inversion, such as when adsorbing the positively charged CTAB surfactant on a negatively charged silica/water interface, [72] and at the TiO2/water [73] and CaF2/water [74,75] interfaces when varying the solution pH, among many other examples. [28,34] The charge reversion or overcompensation is typically driven by specific interactions of multivalent counterions with surfaces that display a relatively high charge density. [76][77][78] For the case of yttrium (and lanthanum), this strong interaction is demonstrated by the formation of binding complexes with the carboxylate headgroup, as revealed by VSFS.…”

Section: Targetting Interfacial Water Molecules To Detect the Charge Reversion Of The Surfacementioning

confidence: 99%

“…Nevertheless, trivalent ions are known to play a central role in proteins and colloidal reactivity, being held responsible for crystallization phenomena, phase separation and surface charge reversion. [28][29][30] For example, the adsorption of Fe 3+ and La 3+ on bacterial and bovine serum albumin proteins was revealed to be strongly pH dependent at micromolar concentrations, [31,32] and caused a charge reversion of lipid surfaces starting from sub-micromolar LaCl3 concentrations. [33,34] The complexation of trivalent ions La 3+ and Fe 3+ to the specific carboxylic acid of a fatty acid monolayer has been probed by X-ray reflectivity, X-ray fluorescence, and more recently VSFS.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

La3+ and Y3+ interactions with the carboxylic acid moiety at the liquid/vapour interface: identification of binding complexes, charge reversal, and detection limits.

Sthoer

Sengupta

Adams

et al. 2021

Preprint

View full text Add to dashboard Cite

Specific interactions of yttrium and lanthanum ions with a fatty acid Langmuir monolayer were investigated using vibrational sum frequency spectroscopy (VSFS). The trivalent ions were shown to interact with the charged form of the carboxylic acid group from nanomolar concentrations (<300 nM). Analysis of the spectral features from both the symmetric and the asymmetric carboxylate modes reveals the presence of at least three distinct coordination structures linked to specific binding configurations. Although the same species were identified for both La3+ and Y3+, they display a different concentration dependence, highlighting the ion-specificity of the interaction. From the response of interfacial water molecules, charge reversion, as well as the formation of yttrium hydroxide complexes, were detected upon increasing the amount of salt in the solution. The binding interaction and kinetics of absorption are sensitive to the solution pH, showing a distinct ion speciation in the interfacial region when compared to the bulk. Changing the subphase pH or adding a monovalent background electrolyte that promotes deprotonation of the carboxylic acid headgroup, could further improve the detection limit of La3+ and Y3+ to concentrations <100 nM. These findings demonstrate that nM concentrations of trace metals contaminants, typically found on monovalent salts, can significantly influence the binding structure and kinetics in Langmuir monolayers.

show abstract

Section: Targetting Interfacial Water Molecules To Detect the Charge Reversion Of The Surfacementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

La3+ and Y3+ interactions with the carboxylic acid moiety at the liquid/vapour interface: identification of binding complexes, charge reversal, and detection limits.

Sthoer

Sengupta

Adams

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…In this respect, multi-scale approaches have been used, where macroscopic foaming properties are compared with the microscopic (nanoscopic) properties of lamellae (foam films) and interfaces [18][19][20][21][22][23][24][25][26][27] as foam's building blocks. Regarding interfaces, on the focus are the traditional adsorption dynamics studies, as well as rheological [9][10][11][12][13][14], electrical [27,29,35,[47][48][49][50][51], and structural [30,50,51] interfacial characteristics-it is emphasized the crucial role of the rate of adsorption, surface viscoelasticity (surface elasticity is the resistance force to mechanical disturbances), interface charging state and interfacial molecular organization, respectively, to foamability, foam stability and foam rheology. Pronounced viscoelastic characteristics of interfaces have been recognized to enhance foaming properties [10,11,14,28,31].…”

Section: Introductionmentioning

confidence: 99%

“…The complexity and high sensitivity of globular proteins to environmental conditions make it difficult to describe their impact on the mechanisms of foam (de)stabilization [8,9,11,12,14,26]. Moreover, protein aggregation (reversible or irreversible) can have complex (enhancing/inhibiting) influence on interfacial and foaming properties as compared to those of the respective native protein [8,19,[39][40][41][42][43][44]49,55]. The behavior of proteins at interfaces and in corresponding foam films and foams is governed by the interplay of the protein concentration and the solvent conditions (salt type and concentration, pH), and the unique effect of pH is of special interest.…”

Section: Introductionmentioning

confidence: 99%

β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 4. Impact on the Stability of Foam Films and Foams

et al. 2020

Self Cite

View full text Add to dashboard Cite

The complexity and high sensitivity of proteins to environmental factors give rise to a multitude of variables, which affect the stabilization mechanisms in protein foams. Interfacial and foaming properties of proteins have been widely studied, but the reported unique effect of pH, which can be of great interest to applications, has been investigated to a lesser extent. In this paper, we focus on the impact of pH on the stability of black foam films and corresponding foams obtained from solutions of a model globular protein—the whey β-lactoglobulin (BLG). Foam stability was analyzed utilizing three characteristic parameters (deviation time, transition time and half-lifetime) for monitoring the foam decay, while foam film stability was measured in terms of the critical disjoining pressure of film rupture. We attempt to explain correlations between the macroscopic properties of a foam system and those of its major building blocks (foam films and interfaces), and thus, to identify structure-property relationships in foam. Good correlations were found between the stabilities of black foam films and foams, while relations to the properties of adsorption layers appeared to be intricate. That is because pH-dependent interfacial properties of proteins usually exhibit an extremum around the isoelectric point (pI), but the stability of BLG foam films increases with increasing pH (3–7), which is well reflected in the foam stability. We discuss the possible reasons behind these intriguingly different behaviors on the basis of pH-induced changes in the molecular properties of BLG, which seem to be determining the mechanism of film rupture at the critical disjoining pressure.

show abstract

“…Furthermore, we wish to mention several other systems because of their model character. As an example, the adsorption of β-lactoglobulin to the air-water interface was studied by Richert et al [435] in the presence of Y 3 + and Nd 3 + cations using a multi-method approach including sum frequency generation (SFG) spectroscopy. Binding of the cations resulted in a reduction of the net protein charge and subsequent aggregation.…”

Section: Other Interfacesmentioning

confidence: 99%

Multivalent ions and biomolecules: Attempting a comprehensive perspective

2020

View full text Add to dashboard Cite

Ions are ubiquitous in nature. They play a key role for many biological processes on the molecular scale, from molecular interactions, to mechanical properties, to folding, to self‐organisation and assembly, to reaction equilibria, to signalling, to energy and material transport, to recognition etc. Going beyond monovalent ions to multivalent ions, the effects of the ions are frequently not only stronger (due to the obviously higher charge), but qualitatively different. A typical example is the process of binding of multivalent ions, such as Ca2+, to a macromolecule and the consequences of this ion binding such as compaction, collapse, potential charge inversion and precipitation of the macromolecule. Here we review these effects and phenomena induced by multivalent ions for biological (macro)molecules, from the “atomistic/molecular” local picture of (potentially specific) interactions to the more global picture of phase behaviour including, e. g., crystallisation, phase separation, oligomerisation etc. Rather than attempting an encyclopedic list of systems, we rather aim for an embracing discussion using typical case studies. We try to cover predominantly three main classes: proteins, nucleic acids, and amphiphilic molecules including interface effects. We do not cover in detail, but make some comparisons to, ion channels, colloidal systems, and synthetic polymers. While there are obvious differences in the behaviour of, and the relevance of multivalent ions for, the three main classes of systems, we also point out analogies. Our attempt of a comprehensive discussion is guided by the idea that there are not only important differences and specific phenomena with regard to the effects of multivalent ions on the main systems, but also important similarities. We hope to bridge physico‐chemical mechanisms, concepts of soft matter, and biological observations and connect the different communities further.

show abstract

Specific Ion Effects of Trivalent Cations on the Structure and Charging State of β-Lactoglobulin Adsorption Layers

Cited by 23 publications

References 64 publications

La3+ and Y3+ interactions with the carboxylic acid moiety at the liquid/vapour interface: identification of binding complexes, charge reversal, and detection limits.

La3+ and Y3+ interactions with the carboxylic acid moiety at the liquid/vapour interface: identification of binding complexes, charge reversal, and detection limits.

β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 4. Impact on the Stability of Foam Films and Foams

Multivalent ions and biomolecules: Attempting a comprehensive perspective

Contact Info

Product

Resources

About