Vrbka, Luboš and Jungwirth, Pavel and Bauduin, Pierre and Touraud, Didier and Kunz, Werner (2006) Specific Ion Effects at Protein Surfaces: A Molecular Dynamics Study of Bovine Pancreatic Trypsin Inhibitor and Horseradish Peroxidase in Selected Salt Solutions. The journal of physical chemistry B 110 (13), pp. 7036-7043.
Download (472kB) - Repository staff only
The distribution of sodium, choline, sulfate, and chloride ions around two proteins, horseradish peroxidase (HRP) and bovine pancreatic trypsin inhibitor (BPTI), is investigated by means of molecular dynamics simulations with the aim to elucidate ion adsorption at the protein surface. Although the two proteins under investigation are very different from each other, the ion distributions around them are remarkably similar. Sulfate is always strongly attached to the proteins, choline shows a significant, but unspecific, propensity for the protein surfaces, and sodium ions have a weak surface affinity, while chloride has virtually no preference for the protein surface. In mixtures of all four ion species in protein solutions, the resulting distributions are almost a superposition of the distributions of sodium sulfate and choline chloride, except that sodium partially replaces choline close to the proteins. The present simulations support a picture of ions interacting with individual ionic and polar amino acid groups rather than with an averaged protein surface. The results thus show how subtle the so-called Hofmeister and electroselectivity effects are in salt solution of proteins, making all simplified interaction models questionable.
|Date:||6 April 2006|
|Institutions:||Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie|
|Subjects:||500 Science > 530 Physics|
500 Science > 540 Chemistry & allied sciences
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||Unknown|
|Deposited On:||30 Jun 2006|
|Last Modified:||20 Jul 2011 20:47|