Aluminum interaction with 2,3-diphosphoglyceric acid. A computational study?

RSC Advances Pub Date: 2015-07-03 DOI: 10.1039/C5RA06796K

Abstract

The interaction of aluminum with 2,3-diphosphoglyceric acid (2,3-DPG) is thought to be one of the strongest interactions of aluminium with a biophosphate molecule. In this article, the affinity energies for a family of Al–(2,3-DPG) complexes are calculated at the DFT level of theory. The study includes a total of 26 structures that vary from 1?:?1 complexes, to 1?:?2 stoichiometry and ternary complexes with citrate, considering different coordination modes and protonation states. Our results demonstrate that in the case of 1?:?1 complexes, the 2,3-DPG ligand could compete with citrate for complexation with aluminum at physiological pH. However, for the rest of the complexes there is a clear preference for Al(Citr)2 > Al(2,3-DPG)(Citr) ternary complex > Al(2,3-DPG)2 complexes. For each of these groups the charge of the ligand determines the affinity but to a lower extent than the nature of the Citr/2,3-DPG ligands. In summary, our results point to a high variety of possible complexation modes of 2,3-DPG to aluminum, showing a higher preference towards the formation of ternary complexes.

Graphical abstract: Aluminum interaction with 2,3-diphosphoglyceric acid. A computational study
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