Laigle A, Chinsky L, Turpin P Y, Hartmann B, Thuong N T, Leng M
Nucleic Acids Res. 1986 Apr 25;14(8):3425-34. doi: 10.1093/nar/14.8.3425.
The thermal stability of the hexanucleoside pentaphosphate m5dCpdGpm5dCpdGpm5 dCpdG has been studied by resonance Raman spectroscopy with 257 nm excitation wavelength. At low temperature and in 3M NaClO4, the Raman spectrum resembles that of poly(dG-dC).poly(dG-dC) in the Z conformation. As the temperature is increased, the position and the intensity of several bands (1312 cm-1, 1482 cm-1, 1584 cm-1 and 1632 cm-1) are modified. The variation of intensity versus temperature is biphasic. Analysis of the results suggests that the increase of temperature induces first a transition from the Z form to an intermediate stable form which then melts. These results and those previously obtained by circular dichroism and 31P nuclear magnetic resonance suggest that the intermediate form belongs to the left family but with changes in the stacking of the bases and the geometry of the phosphate groups as compared to the canonical Z form.
已通过共振拉曼光谱法在257nm激发波长下研究了六核苷五磷酸m5dCpdGpm5dCpdGpm5dCpdG的热稳定性。在低温和3M高氯酸钠中，拉曼光谱类似于Z构象的聚（dG-dC）.聚（dG-dC）。随着温度升高，几个谱带（1312cm -1、1482cm -1、1584cm -1和1632cm -1）的位置和强度发生改变。强度随温度的变化是双相的。结果分析表明，温度升高首先引起从Z型到中间稳定型的转变，然后中间稳定型熔化。这些结果以及先前通过圆二色性和31P核磁共振获得的结果表明，中间型属于左手家族，但与标准Z型相比，碱基堆积和磷酸基团几何结构发生了变化。
