Hartmann B, Genest D, Thuong N T, Ptak M, Leng M
Biochimie. 1986 May;68(5):739-43. doi: 10.1016/s0300-9084(86)80168-7.
The thermal stability of the hexanucleoside pentaphosphate d(br5CGbr5CGbr5CG) has been studied at two nucleotide concentrations, in the presence of 1 M NaClO4. At low nucleotide concentration (7 X 10(-5) M), circular dichroism experiments show a conformational transition from the Z conformation to another conformation, named X, which is not the B conformation, as the temperature is increased from 0 to 35 degrees C. Between 40 and 65 degrees C, another transition is observed which corresponds to the melting of the X conformation. At higher nucleotide concentration (2 X 10(-3) M), circular dichroism and 31P nuclear magnetic resonance experiments show that at low temperature (br5dC-dG)3 adopts the Z conformation. There are associations between the oligonucleotides which progressively disappear as the temperature increases. In the range 35-60 degrees C a transition from the Z conformation to another conformation is observed. This new conformation is the X conformation detected at low nucleotide concentration.
在1 M高氯酸钠存在的情况下，研究了六核苷五磷酸d(br5CGbr5CGbr5CG)在两种核苷酸浓度下的热稳定性。在低核苷酸浓度（7×10⁻⁵ M）时，圆二色性实验表明，随着温度从0℃升高到35℃，会发生从Z构象到另一种构象（称为X构象，而非B构象）的构象转变。在40℃至65℃之间，观察到另一种转变，这对应于X构象的解链。在较高核苷酸浓度（2×10⁻³ M）时，圆二色性和³¹P核磁共振实验表明，在低温下(br5dC-dG)3采用Z构象。寡核苷酸之间存在缔合，随着温度升高，这种缔合会逐渐消失。在35 - 60℃范围内，观察到从Z构象到另一种构象的转变。这种新构象就是在低核苷酸浓度下检测到的X构象。
