Specific ion binding to macromolecules : Effects of hydrophobicity and ion pairing

Summary, in English

Using molecular dynamics simulations in an explicit aqueous solvent, we examine the binding of fluoride versus iodide to a spherical macromolecule with both hydrophobic and positively charged patches. Rationalizing our observations, we divide the ion association interaction into two mechanisms: (1) poorly solvated iodide ions are attracted to hydrophobic surface patches, while (2) the strongly solvated fluoride and to a minor extent also iodide bind via cation-anion interactions. Quantitatively, the binding affinities vary significantly with the accessibility of the charged groups as well as the surface potential; therefore, we expect the ion-macromolecule association to be modulated by the local surface characteristics of the (bio-)macromolecule. The observed cation-anion pairing preference is in excellent agreement with experimental data.

• Author: Mikael Lund; Robert Vácha; Pavel Jungwirth
• Publishing year: 2008-04-01
• Language: English
• Pages: 3387-3391
• Publication/Series: Langmuir
• Volume: 24
• Issue: 7
• Links: http://dx.doi.org/10.1021/la7034104
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Theoretical Chemistry (including Computational Chemistry)
• Status: Published
• ISBN/ISSN/Other: ISSN: 0743-7463