LAUSR

Lithium is profoundly different from other ions in the body in multiple ways. Extracellular concentrations of calcium, sodium, potassium, and hydrogen ions must be closely regulated for well-being. On the other hand, the body does not closely regulate lithium but rather adapts reasonably well to lithium concentration variation of over a thousandfold, in spite of the fact that lithium interacts with many biological molecules. This stability coupled with interactiveness implies the existence of myriad mutually compensating lithium-modulated processes, which are almost completely not understood. In this study we explore the interaction of lithium, sodium, potassium, and rubidium with bilayer membranes comprised of POPC, using molecular dynamics simulations. Lithium, but not any of the others, forms a long-lasting noncovalent bond simultaneously with the headgroup phosphate and the CO group of the Sn2 chain. This interaction significantly alters the structure and the surface area of the membrane.