Hydration number, topological control, and ion selectivity.
The topological control hypothesis presented by Bostick and Brooks [Proc. Natl. Acad. Sci. U.S.A. 2007, 104, 9260] has sought to explain binding selectivity in potassium channels based on the premise that a universal measure of ion solvation in different environments is provided by its average coordination structure in bulk water. This leads to the view that ion selectivity is predominantly controlled by the number of ligands coordinating the ion and that the chemical type of those ligands plays a minor role. The significance of the topological control hypothesis and its ability to predict ion selectivity in protein binding sites are examined. It is shown that the framework encounters increasing difficulties when different protein binding sites with similar coordination numbers are considered.
Yu
Haibo
H
Department of Biochemistry and Molecular Biology, University of Chicago, Illinois 60637, USA.
Noskov
Sergei Yu
SY
Roux
Benoît
B
D008958:Models, Molecular; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000737:chemistry* / Q000378:metabolism*; D015203:Reproducibility of Results; D012964:Sodium / Q000378:metabolism*; D013379:Substrate Specificity; D013816:Thermodynamics; D014867:Water / Q000737:chemistry* / Q000378:metabolism
D015221:Potassium Channels; D014867:Water; D012964:Sodium; D011188:Potassium