Torri C. Roark, Luis A. Palacio, P. Gurnev
Jan 31, 2012
Citations
0
Influential Citations
3
Citations
Quality indicators
Journal
Biophysical Journal
Abstract
Lithium is a naturally occurring alkali metal which is very easily ionized to Li+, especially in aqueous solutions. Lithium is found mainly in mineral and seawater and in trace amounts in the human body. Lithium ions are being used in various fields ranging from energy storage to the treatment of mental illnesses including bipolar disorder and schizophrenia. The reason why lithium is such a peculiar ion is not exactly known except that its mode of interactions with charged surfaces depends on its hydration properties (i.e. interaction with nearby water molecules). We report two kinds of experimental measurements of lithium interactions with charged lipid membranes. One set of experiments involves X-ray scattering of multilamellar lipid vesicles in solution for which we measure how lithium salts modify van der Waals and electrostatic forces between neighboring membranes. The other set of measurements compare the effect of added lithium on the activity of gramicidin channels in neutral and negatively charged lipid bilayers. We find that in both x-ray and channel measurements, lithium ions modify lipid interactions in a manner that differs from other monovalent posititive ions.