2010 Volume 59 Issue 2 Pages 135-143
Nucleosides and nucleotides, which are the basic components of nucleic acids, crystallize as hydrates. Numbers of crystal water molecules are a function of relative humidity surrounding crystals. Besides, phase transitions occur around 200K, which couple with the ordering of crystal water molecules. Neutron diffraction analysis on the humidity- and temperature-induced phase transitions of nucleotide hydrates was carried out. Neutron crystal structures showed that there were hydrogen-bonding networks common to nucleotide hydrates, switching of long-ranged hydrogen-bonding networks, and fluctuating crystal water molecules anchoring through hydrogen bonds.