Interaction of organic ions with proteins
| Autor: | Carlos Drummond, Delfi Bastos-González, Jordi Faraudo, Leonor Pérez-Fuentes |
|---|---|
| Přispěvatelé: | Biocolloid and Fluid Physics Group, University of Granada [Granada], Centre de Recherche Paul Pascal (CRPP), Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Ciència de Materials de Barcelona (ICMAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), project CTS-6270 (Junta de Andalucıa, Spain) and the Spanish ‘‘Ministerio de Economıa y Competitividad (MINECO), Plan Nacional de Investigacion, Desarrollo e Innovacion Tecnolo´gica (I + D + i)’’ (Project FIS2016-80087-C2-1-P) financial support from the Spanish Ministry of Economy and Competitiveness, through the ‘‘Severo Ochoa’’ Programme for Centres ofExcellence in R & D (SEV-2015-0496) awarded to ICMAB. L. P.-F. acknowledges the COST Action MP1303: Understanding and Controlling Nano and Mesoscale Friction. |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Models
Molecular Protein Conformation Tetraphenylborate Inorganic chemistry Analytical chemistry Ionic bonding 02 engineering and technology 010402 general chemistry 01 natural sciences Arsenicals Ion Colloid chemistry.chemical_compound Electrokinetic phenomena Adsorption Animals Bovine serum albumin biology Chemistry Proteins General Chemistry Quartz crystal microbalance 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences biology.protein Cattle Polystyrene [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] 0210 nano-technology Hydrophobic and Hydrophilic Interactions Protein Binding |
| Zdroj: | Soft Matter Soft Matter, Royal Society of Chemistry, 2016, 13, pp. 1120-1131. ⟨10.1039/c6sm02048h⟩ |
| ISSN: | 1744-683X 1744-6848 |
| DOI: | 10.1039/c6sm02048h⟩ |
| Popis: | In this study we have investigated how different proteins interact with big organic ions. Two ions that are similar in size and chemical structure (Ph4B− anion and Ph4As+ cation) were studied. The proteins chosen are the two major allergenic proteins of cow's milk, β-lactoglobulin and β-casein, and bovine serum albumin, BSA, as the reference protein. First, a quantitative study to determine the hydrophobic degree of the proteins was performed. Then, electrokinetic and stability measurements on protein-coated polystyrene (PS) microspheres as a function of the tetraphenyl ion concentration were carried out. Our results show that the affinity of the organic ions depends on the hydrophobicity of the interface. Big charge inversions and re-stabilization patterns were observed at very low concentrations of tetraphenyl ions for the most hydrophobic protein studied (with β-casein). Besides, the ionic concentrations needed to destabilize these colloidal systems were roughly one order of magnitude lower for the anion than for the cation. In addition, we studied conformational changes of the adsorbed proteins with a quartz crystal microbalance. Proteins were adsorbed onto hydrophobic flat substrates and then exposed to the tetraphenyl ions. The protein films swelled or collapsed as a function of the accumulation of tetraphenyl ions. Similarly to the electrokinetic/stability studies, the ionic concentration necessary to trigger structural changes of the protein films was one order of magnitude larger for the cation than for the anion. All the results evidence that the accumulation of these organic ions on an interface depends directly on its degree of hydrophobicity. We attribute the different interactions of the anion and the cation with these interfaces to their dissimilar hydration, which makes the anion show a more hydrophobic behaviour than the cation. |
| Databáze: | OpenAIRE |
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