Interaction of aminoacids with cations. I - The glycine-Li ⁺-n(H20) (n = 0-3) complexes

The energy minima of systems made of a glycine molecule, a lithium cation and a various number of water molecules have been determined with the help of quantum chemical computations at the B3LYP Density Functional Theory level of computation and the standard 6-311++G (d,p) basis set. Several structures, close in energy are found and the presence of one or two water molecules around the cation modifies the order of stability. This order is not modified by the presence of a third water molecule. The results are discussed in view of better understanding the structure of aqueous solutions of these species and the possible interactions of lithium cations with peptides. © 2004 Elsevier B.V. All rights reserved.