1H and 31P NMR study of ADP and GDP spontaneous synthesis from 2-methylimidazole-activated AMP and GMP nucleotides and inorganic phosphate

Abstract

¹ H and ³¹P NMR data show that adenosine 5′-(2-methylimidazol-1-ylphosphonate) (2-MeImpA) and guanosine 5′-(2-methylimidazol-1-ylphosphonate) (2-MeImpG), known as possible prebiotic precursors of polynucleotides, produce the corresponding diphosphonucleotides in sodium phosphate solution at pD 7.6. Phosphate ions also enhance the hydrolysis of these molecules by activating a water molecular associated as a weak complex with the phosphoryl moiety of 2-MeImpA and 2-MeImpG. A kinetic study was done by quantitative ¹H NMR spectroscopy and mechanistic hypotheses were tested by semiempirical PM3 modelling.