Novikov I A, Ivannikov A I, Kobelev V S, Volkov V Ia
Mol Biol (Mosk). 1985 Jul-Aug;19(4):1029-33.
Temperature dependence of spin-spin proton relaxation times of DNA and bound water and the content of bound water in the samples of DNA, saturated with water in the atmosphere with different relative humidities from 0 to 100% were studied by means of pulsed NMR. It is shown that the temperature transition in the system of DNA-bound water in the interval 18-35 degrees is observed only when the relative humidity is more than 70% and the double-stranded structure of DNA exists. The transition of DNA from one conformation into another passes through some intermediate state more labile and probably less ordered. This transition is accompanied by changes in the structure of the hydration shell. In the case when relative humidity is greater than 80%, the partial dehydration of DNA stimulated by the transition is observed. This dehydration increases with the increase of relative humidity.
通过脉冲核磁共振研究了DNA与结合水的自旋-自旋质子弛豫时间的温度依赖性，以及在相对湿度从0到100%的大气中用水饱和的DNA样品中结合水的含量。结果表明，仅当相对湿度超过70%且DNA的双链结构存在时，才会在18-35摄氏度区间内观察到DNA-结合水体系中的温度转变。DNA从一种构象转变为另一种构象会经过一些更不稳定且可能更无序的中间状态。这种转变伴随着水合壳结构的变化。当相对湿度大于80%时，会观察到由转变引发的DNA部分脱水现象。这种脱水随着相对湿度的增加而增加。
