Aluminum(III) interactions with the acid derivative amino acid chains

Aluminum(III) and magnesium(II) interactions with the asparagine and glutam ine amino acid chains are studied by the density functional approach. Bader analysis and natural bonding orbital analysis were also performed to analy ze the bonding interactions. We began by studying the interactions between the cations and the formamide, and we added two methyl groups sequentially to model more accurately the asparagine and the glutamine amino acid chains . The strongest binding energies for aluminum(III) and magnesium(II) are 37 2 and 140 kcal/mol, respectively, for asparagine chain and 404 and 145 kcal /mol, respectively, for the glutamine chain. The addition of the first meth yl to the formamide has an important effect on the formamide-metal complexe s, while the addition of the second methyl does not greatly change the prop erties of the complexes. The binding energies of these complexes are signif icantly smaller than tho se of the aluminum(III)/magnesium(II) interactions with the acidic amino acid chains.