[Specific interactions of isoguanine with the neutral and deprotonated carboxylic group of amino acids: results of model quantum chemical calculations]. / Kvantovokhimichni rozrakhunky spetsyfichnoï vzaiemodiï izohuaniny z neitral'noho ta deprotonovanoiu karboksyl'noiu hrupoiu aminokyslot.

The MNDO/H quantum chemical calculations performed in order to estimate energetic features of the isoguanine (isoGua) prototropic tautomers complexes with acetic acid and its carboxylate-ion (models of neutral and deprotonated forms of amino acid carboxylic group) demonstrate ability of the latter to induce the N9H-->N7H tautomeric transition in the base, being characteristic to other purine bases as well. By contrast, the neutral carboxylic group forms the most stable complex with the ground-state isoGua tautomer N3HN9H.