Xanthine, xanthosine and its nucleotides: solution structures of neutral and ionic forms, and relevance to substrate properties in various enzyme systems and metabolic pathways.

@article{Kulikowska2004XanthineXA,
  title={Xanthine, xanthosine and its nucleotides: solution structures of neutral and ionic forms, and relevance to substrate properties in various enzyme systems and metabolic pathways.},
  author={Ewa Kulikowska and Borys Kierdaszuk and David Shugar},
  journal={Acta biochimica Polonica},
  year={2004},
  volume={51 2},
  pages={493-531}
}
The 6-oxopurine xanthine (Xan, neutral form 2,6-diketopurine) differs from the corresponding 6-oxopurines guanine (Gua) and hypoxanthine (Hyp) in that, at physiological pH, it consists of a approximately 1:1 equilibrium mixture of the neutral and monoanionic forms, the latter due to ionization of N(3)-H, in striking contrast to dissociation of the N(1)-H in… CONTINUE READING