| 1. |
- BUCCIARELLI, SASKIA, et al.
(författare)
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Extended Law of Corresponding States Applied to Solvent Isotope Effect on a Globular Protein
- 2016
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Ingår i: The Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 7:9, s. 1610-1615
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Tidskriftsartikel (refereegranskat)abstract
- Investigating proteins with techniques such as NMR or neutron scattering frequently requires the partial or complete substitution of D2O for H2O as a solvent, often tacitly assuming that such a solvent substitution does not significantly alter the properties of the protein. Here, we report a systematic investigation of the solvent isotope effect on the phase diagram of the lens protein gamma B-crystallin in aqueous solution as a model system exhibiting liquid-liquid phase separation. We demonstrate that the observed strong variation of the critical temperature T-c can be described by the extended law of corresponding states for all H2O/D2O ratios, where scaling of the temperature by T-c or the reduced second virial coefficient accurately reproduces the binodal, spinodal, and osmotic compressibility. These findings highlight the impact of H2O/D2O substitution on gamma B-crystallin properties and warrant further investigations into the universality of this phenomenon and its underlying mechanisms.
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| 2. |
- Larsson, Johan, et al.
(författare)
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The effect of the anomeric configuration on the micellization of hexadecylmaltoside surfactants
- 2019
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 35:43, s. 13904-13914
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Tidskriftsartikel (refereegranskat)abstract
- The self-assembly of the two anomeric forms of n-hexadecyl-D-maltopyranoside (denoted α-C16G2 and β-C16G2) has been studied in dilute aqueous solution by means of surface tension measurements, scattering methods (dynamic light scattering, static light scattering, and small-angle X-ray and neutron scattering) and cryo-transmission electron microscopy at different surfactant concentrations and temperatures. Surface tension measurements demonstrate differences in the surfactant adsorption at the air-water interface, where α-C16G2 shows a lower CMC than β-C16G2. Similarly, micelle morphology was found to profoundly depend on anomerism. β-C16G2 preferentially forms very elongated micelles with large persistence lengths, whereas α-C16G2 assembles into smaller micelles for which the structure varies with concentration and temperature. The differences between the two surfactant anomers in terms of self-assembly can be attributed to the interaction between neighboring headgroups. Specifically, β-C16G2 allows for a closer packing in the palisade layer, hence reducing the micelle curvature and promoting the formation of more elongated micelles. Strong intermolecular headgroup interactions may also account for the observed rigidity of the micelles.
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| 3. |
- Mahmoudi, Najet, et al.
(författare)
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Making Food Protein Gels via an Arrested Spinodal Decomposition
- 2015
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Ingår i: The Journal of Physical Chemistry Part B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 119:50, s. 15522-15529
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Tidskriftsartikel (refereegranskat)abstract
- We report an investigation of the structural and dynamic properties of mixtures of food colloid casein micelles and low molecular weight poly(ethylene oxide). A combination of visual observations, confocal laser scanning microscopy, diffusing wave spectroscopy, and oscillatory shear rheometry is used to characterize the state diagram of the mixtures and describe the structural and dynamic properties of the resulting fluid and solid-like structures. We demonstrate the formation of gel-like structures through an arrested spinodal decomposition mechanism. We discuss our observations in view of previous experimental and theoretical studies with synthetic and food colloids, and comment on the potential of such a route toward gels for food processing.
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| 4. |
- Valldeperas, Maria, et al.
(författare)
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Interfacial properties of lipid sponge-like nanoparticles and the role of stabilizer on particle structure and surface interactions
- 2019
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Ingår i: Soft Matter. - : ROYAL SOC CHEMISTRY. - 1744-683X .- 1744-6848. ; 15:10, s. 2178-2189
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Tidskriftsartikel (refereegranskat)abstract
- The advantage of using nonlamellar lipid liquid crystalline phases has been demonstrated in many applications, such as drug delivery, protein encapsulation and crystallisation. We have recently reported that a mixture of mono-and diglycerides is able to form sponge-like nanoparticles (L-3-NPs) with large enough aqueous pores to encapsulate macromolecules such as proteins. Here we use small angle neutron scattering (SANS) to reveal morphology, structural and chemical composition of these polysorbate 80 (P80) stabilized sponge phase nanoparticles, not previously known. Our results suggest that L-3-NPs have a core-shell sphere structure, with a shell rich in P80. It was also found that even if P80 is mostly located on the surface, it also contributes to the formation of the inner sponge phase structure. An important aspect for the application and colloidal stability of these particles is their interfacial properties. Therefore, the interfacial behaviour of the nanoparticles on hydrophilic silica was revealed by Quartz crystal microbalance with dissipation (QCM-D) and neutron reflectivity (NR). Adsorption experiments reveal the formation of a thin lipid layer, with the dimension corresponding to a lipid bilayer after L-3-NPs are in contact with hydrophilic silica. This suggests that the diglycerol monoleate/ Capmul GMO-50/P80 particles reorganize themselves on this surface, probably due to interactions between P80 head group and SiO2.
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