STATICS AND DYNAMICS OF ORIENTED DNA AS SEEN BY NEUTRONS

Neutron-scattering experiments are reported which provide information on the interaction balance between the conformations of DNA, the level of hydration, and the excess salt content. The latter is found to influence the array of helix axes in wet-spun DNA films. An admixture of C-type axial repeat distances with short correlation length being favored by the water content is observed for NaDNA. The H2O/D2O contrast for the coherent inelastic spectrum for LiDNA at 75% relative humidity (r.h.) shows that water and DNA move in phase. Delocalization of the DNA hydrogens with increasing humidity and temperature is observed in the incoherent spectrum.