Potential Energy Surfaces for the Gas-Phase Interaction between α-Alanine and Alkali Metal Ions (Li+, Na+, K+). A Density Functional Study
- 2 November 2001
- journal article
- research article
- Published by American Chemical Society (ACS) in Inorganic Chemistry
- Vol. 40 (25) , 6439-6443
- https://doi.org/10.1021/ic010196j
Abstract
The conformations of α-alanine and those of the eight most stable adducts that it forms with lithium, sodium, and potassium cations were studied by means of the density functional theory using the hybrid B3LYP exchange correlation potential and the 6−311++G** basis set. Minima and transition states characterizing the energetic paths for the interaction of the three metal ions with the free amino acid were explored in detail, and the results show that they are almost the same in the cases of lithium and sodium ions. At the absolute minimum, the Li+ and Na+ cations appear to be contemporaneously linked to the carbonyl oxygen and nitrogen atoms of α-alanine. Slight differences were found for potassium; the most stable adduct has the cation coordinated to both oxygen atoms of carboxyl function. The influence of the low-energy conformers in the determination of the gas-phase absolute affinities is demonstrated.Keywords
This publication has 29 references indexed in Scilit:
- Gas-phase metal ion (Li+, Na+, Cu+) affinities of glycine and alanineJournal of Inorganic Biochemistry, 2000
- Fragmentation of an alkali metal-attached peptide probed by collision-induced dissociation Fourier transform mass spectrometry and computational methodologyJournal of Mass Spectrometry, 1999
- A Quantitative Basis for a Scale of Na+ Affinities of Organic and Small Biological Molecules in the Gas PhaseJournal of the American Chemical Society, 1999
- Lithium and Sodium Ion Binding Energies of N-Acetyl and N-Glycyl Amino AcidsJournal of the American Chemical Society, 1999
- Interaction of Alkali Metal Cations (Li+-Cs+) with Glycine in the Gas Phase: A Theoretical StudyChemistry – A European Journal, 1998
- Na+ Binding to Cyclic and Linear Dipeptides. Bond Energies, Entropies of Na+ Complexation, and Attachment Sites from the Dissociation of Na+-Bound Heterodimers and ab Initio CalculationsJournal of the American Chemical Society, 1998
- The Relative Copper(I) Ion Affinities of Amino Acids in the Gas PhaseJournal of the American Chemical Society, 1995
- On the sodium and lithium ion affinities of some α-amino acidsJournal of Mass Spectrometry, 1993
- Desorption–ionization and in‐flight fragmentation of monoalkali‐glycine adducts: Plasma‐desorption mass spectrometry and Ab initio calculationsRapid Communications in Mass Spectrometry, 1993
- Proton and sodium ion affinities of glycine and its sodium salt in the gas phase. Ab initio calculationsJournal of Mass Spectrometry, 1992