Lateral Protein-Protein Interactions at Hydrophobic and Charged Surfaces as a Function of pH and Salt Concentration
| Autor: | Jana Hladílková, Thomas H. Callisen, Mikael Lund |
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| Rok vydání: | 2016 |
| Předmět: |
Models
Molecular Surface Properties Static Electricity Salt (chemistry) 02 engineering and technology 01 natural sciences Protein–protein interaction Adsorption Ascomycota 0103 physical sciences Monolayer Static electricity Materials Chemistry Osmotic pressure Physical and Theoretical Chemistry chemistry.chemical_classification 010304 chemical physics Lipase Hydrogen-Ion Concentration 021001 nanoscience & nanotechnology Surfaces Coatings and Films Amino acid Crystallography Isoelectric point chemistry Chemical physics Salts 0210 nano-technology Hydrophobic and Hydrophilic Interactions Monte Carlo Method |
| Zdroj: | The journal of physical chemistry. B. 120(13) |
| ISSN: | 1520-5207 |
| Popis: | Surface adsorption of Thermomyces lanuginosus lipase (TLL)-a widely used industrial biocatalyst-is studied experimentally and theoretically at different pH and salt concentrations. The maximum achievable surface coverage on a hydrophobic surface occurs around the protein isoelectric point and adsorption is reduced when either increasing or decreasing pH, indicating that electrostatic protein-protein interactions in the adsorbed layer play an important role. Using Metropolis Monte Carlo (MC) simulations, where proteins are coarse grained to the amino acid level, we estimate the protein isoelectric point in the vicinity of charged surfaces as well as the lateral osmotic pressure in the adsorbed monolayer. Good agreement with available experimental data is achieved and we further make predictions of the protein orientation at hydrophobic and charged surfaces. Finally, we present a perturbation theory for predicting shifts in the protein isoelectric point due to close proximity to charged surfaces. Although this approximate model requires only single protein properties (mean charge and its variance), excellent agreement is found with MC simulations. |
| Databáze: | OpenAIRE |
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