Circular dichroism study of supramolecular assemblies of guanosine 5'-monophosphate.

ABSTRACT: Concentration and temperature dependent studies of the circular dichroism of dianionic guanosine 5'-monophosphate (5'-GMP), where the cation was Na(+), K(+), or Rb(+) ion, were done to obtain information regarding the nature of the self-assembled 5'-GMP species in aqueous solution, including G-quartets and other structures. Concentrations in the 0.05-0.85 M range and temperatures in the 5-50 °C range were used. At the highest concentrations and 5 °C, Na(2)(5'-GMP) and K(2)(5'-GMP) formed a cholesteric phase, but Rb(2)(5'-GMP) did not. Evidence for antiparallel base stacking (stacked with opposite polarity; head to head) was observed for Rb(2)(5'-GMP) but not for the Na(+) or K(+) salts. This structure, believed to be G-quartets, had a melting temperature of 15 °C and dissociated into a sec

SUBMITTER: Panda M 

PROVIDER: S-EPMC3131790 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature