O'Connor T, Mansy S, Bina M, McMillin D R, Bruck M A, Tobias R S
Biophys Chem. 1982 Apr;15(1):53-64. doi: 10.1016/0301-4622(82)87016-6.
The pH-dependent structure of calf thymus DNA is analyzed using Raman spectroscopy. The Raman spectra in the acidic region demonstrate that denaturation occurs in several steps. The binding of H+ to adenine and cytosine residues is accompanied by a decrease in the percentage of DNA in the B-conformation and a concurrent increase in a conformation most probably related to the C-form. The denaturation of DNA is observed at pH 3.3 and parallels the protonation of guanine bases. The Raman spectra of calf thymus DNA in the basic region (above pH 10) show that guanine residues are deprotonated at lower pH value than are thymine residues. In addition, Raman spectra in the basic region detect conformational changes of the phosphate backbone different from those found in the acidic region.
利用拉曼光谱分析了小牛胸腺DNA的pH依赖性结构。酸性区域的拉曼光谱表明，变性过程分几步发生。H⁺与腺嘌呤和胞嘧啶残基的结合伴随着B型构象的DNA百分比下降，以及最可能与C型相关的构象同时增加。在pH 3.3时观察到DNA变性，且与鸟嘌呤碱基的质子化平行。碱性区域（pH值高于10）的小牛胸腺DNA拉曼光谱表明，鸟嘌呤残基比胸腺嘧啶残基在更低的pH值下发生去质子化。此外，碱性区域的拉曼光谱检测到磷酸主链的构象变化与酸性区域不同。
