Exploring the Interfacial Structure of Protein Adsorbates and the Kinetics of Protein Adsorption: An In Situ High-Energy X-ray Reflectivity Study

Evers, Florian; Shokuie, Kaveh; Paulus, Michael; Sternemann, Christian; Czeslik, Claus; Tolan, Metin

doi:10.1021/la801642s

Cited by 38 publications

(60 citation statements)

References 35 publications

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“…3,4,81,[90][91][92] In particular, lysozyme has often served as a model protein in physicochemical studies assessing the influence of different solution conditions, e.g., pH value, salt content or polymer concentration. 21,37,[93][94][95][96] Moreover, lysozyme is one of the most studied proteins with respect to modelling of protein-protein interactions. 24,32,38,40,47,97 Therefore, we will focus on the binodals of lysozyme solutions here, although our analysis can also be applied to other protein systems.…”

Section: Of Protein Solutionsmentioning

confidence: 99%

Extended law of corresponding states for protein solutions

Platten

Valadez-Pérez

Castañeda-Priego

et al. 2015

The Journal of Chemical Physics

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The so-called extended law of corresponding states, as proposed by Noro and Frenkel [J. Chem. Phys. 113, 2941 (2000)], involves a mapping of the phase behaviors of systems with short-range attractive interactions. While it has already extensively been applied to various model potentials, here we test its applicability to protein solutions with their complex interactions. We successfully map their experimentally determined metastable gas-liquid binodals, as available in the literature, to the binodals of short-range square-well fluids, as determined by previous as well as new Monte Carlo simulations. This is achieved by representing the binodals as a function of the temperature scaled with the critical temperature (or as a function of the reduced second virial coefficient) and the concentration scaled by the cube of an effective particle diameter, where the scalings take into account the attractive and repulsive contributions to the interaction potential, respectively. The scaled binodals of the protein solutions coincide with simulation data of the adhesive hard-sphere fluid. Furthermore, once the repulsive contributions are taken into account by the effective particle diameter, the temperature dependence of the reduced second virial coefficients follows a master curve that corresponds to a linear temperature dependence of the depth of the square-well potential. We moreover demonstrate that, based on this approach and cloud-point measurements only, second virial coefficients can be estimated, which we show to agree with values determined by light scattering or by Derjaguin-Landau-Verwey-Overbeek (DLVO)-based calculations.

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Section: Of Protein Solutionsmentioning

confidence: 99%

Extended law of corresponding states for protein solutions

Platten

Valadez-Pérez

Castañeda-Priego

et al. 2015

The Journal of Chemical Physics

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“…30 The amount and volume fraction of absorbed proteins at the air− water interface can be estimated based on ED profiles, assuming the adsorbed layer(s) is a mixture of the protein and subphase solution. 23,29,31,32 The volume fraction profile of adsorbed Mms6, Φ Mms6 (z), can be directly related to ρ(z) as follows 29 3 , MW ∼10 kDa). 33 The mass of adsorbed proteins per surface area, Γ s , can be derived from obtained volume fraction profile Φ Mms6 (z).…”

Section: ■ Experimental Detailsmentioning

confidence: 99%

Interfacial Properties and Iron Binding to Bacterial Proteins That Promote the Growth of Magnetite Nanocrystals: X-ray Reflectivity and Surface Spectroscopy Studies

Wang

et al. 2012

Langmuir

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Surface sensitive X-ray scattering and spectroscopic studies have been conducted to determine structural properties of Mms6, the protein in Magnetospirillum magneticum AMB-1 that is implicated as promoter of magnetite nanocrystals growth. Surface pressure versus molecular area isotherms indicate Mms6 forms stable monolayers at the aqueous/vapor interface that are strongly affected by ionic conditions of the subphase. Analysis of X-ray reflectivity from the monolayers shows that the protein conformation at the interface depends on surface pressure and on the presence of ions in the solutions, in particular of iron ions and its complexes. X-ray fluorescence at grazing angles of incidence from the same monolayers allows quantitative determination of surface bound ions to the protein showing that ferric iron binds to Mms6 at higher densities compared to other ions such as Fe 2+ or La 3+ under similar buffer conditions. ABSTRACT: Surface sensitive X-ray scattering and spectroscopic studies have been conducted to determine structural properties of Mms6, the protein in Magnetospirillum magneticum AMB-1 that is implicated as promoter of magnetite nanocrystals growth. Surface pressure versus molecular area isotherms indicate Mms6 forms stable monolayers at the aqueous/vapor interface that are strongly affected by ionic conditions of the subphase. Analysis of X-ray reflectivity from the monolayers shows that the protein conformation at the interface depends on surface pressure and on the presence of ions in the solutions, in particular of iron ions and its complexes. X-ray fluorescence at grazing angles of incidence from the same monolayers allows quantitative determination of surface bound ions to the protein showing that ferric iron binds to Mms6 at higher densities compared to other ions such as Fe 2+ or La 3+ under similar buffer conditions. Disciplines Biochemical and Biomolecular

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“…[5]. Adsorption on hydrophilic silicon surfaces is related to the electrostatic interaction between the protein and the surface [6,7] and thus depends on the charge of the protein which itself varies with the isoelectric point (PI) and pH [8][9][10][11]. Van der Waals interactions may also have non-negligible effects on the adsorption, as illustrated recently [12].…”

Section: Introductionmentioning

confidence: 99%