DNA温度效应的Raman光谱研究

Temperature Dependence Study of Calf Thymus DNA by Raman Spectra

测定了不同温度下DNA纤维和溶液的拉曼光谱。结果表明 :当温度变化时 ,碱基、磷酸根等特征振动都不同程度的受到影响 ,谱线强度、频率随温度呈非线性变化。在所有的振动模式中 ,腺嘌呤A的特征振动受到温度的影响最大。除了磷酸根的谱线 110 1cm-1以外 ,其余谱线的波数变化均随温度的升高向低波数移动 ,而且波数的移动主要集中在变性峰的起始点 70℃左右。另外还讨论了拉曼谱线强度随温度的变化关系 ,得到了 38,82℃ (纤维为 85℃ ) 2个峰 ,其中 38℃与DNA的功能活跃区有关 ,82℃ (和 85℃ )为DNA的变性点 ,与DSC(差示扫描量热法 )

In this paper, the authors obtained Raman spectra of DNA in fiber and aqueous solution at different temperatures. These spectra revealed that the vibration of bases and phosphate group were influenced by varying temperature. Adenine was the most sensitive to varying temperature in all of the vibrational modes. The wave numbers of most of the vibrational modes decreased as the temperature increased except for the band at 1101 cm(-1), and the shift of wave numbers mainly concentrated upon the beginning point of denaturation at 70 degreesC. The temperature dependence of Raman intensity was discussed, and two peaks were obtained at 38 and 82 degreesC, respectively. The results obtained by Raman spectra were in agreement with experimental data by DSC at 82 degreesC. The peak at 38 degreesC was related to the biological activity region of DNA function.