A 2H-nmr study of the DNA hydration water in solid li-DNA assemblies

✍ Scribed by Rolf Brandes; David R. Kearns; Allan Rupprecht

• Publisher: Wiley (John Wiley & Sons)
• Year: 1988
• Tongue: English
• Weight: 855 KB
• Volume: 27
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360270502

✦ Synopsis

High-resolution *H-nmr is employed to monitor the D20 in hydrated solids of Li-DNA prepared from solution by three different methods: lyophilization, slow evaporation of the water, and wet spinning in alcohol. From the spectral shapes and spin-spin relaxation measurements, the DNA in the lyophilized samples is found to be locally ordered with a domain size of -0.4 pm. Much longer range macrosopic ordering is found in samples prepared by slow evaporation of the water. Here the DNA spontaneously assembles into a structure that is probably cholesteric, in which the pitch axis is perpendicular to the plane on which the DNA dried. The wet-spinning method produces macroscopically, uniaxidy oriented DNA molecules with a maximum helix axis disorder of 12". To aid in the comparison between calculated and experimental line shapes, a two-dimensional technique is employed to separate the contributions to the line width arising from DNA static disorder, magnetic inhomogeneities, and spin-spin relaxation.