Fox G M, Schmid C W
Biochim Biophys Acta. 1980 Oct 17;609(3):349-63. doi: 10.1016/0005-2787(80)90109-4.
Human single copy DNA renatured under relatively non-stringent conditions (50 degrees C, 0.36 M Na+) forms two components with different thermal stabilities: a high temperature component melting at a temperature (81 degrees C, 0.18 M Na+) expected for well-paired duplex and a low temperature component melting at 55 degrees C (0.18 M Na+). The production of the high and low temperature components has been examined as a function of C0t (product of concentration and time in units of mol/s per l) value and renaturation temperature. The duplex formed has been characterized by its resistance to S1 endonuclease and its length has been determined by gel electrophoresis. As a result of these experiments and related controls we conclude that the low temperature component is not an artifact of DNA fragment length, nonspecific base pairing or hydroxyapatite chromatography conditions. We attribute the low thermal stability of this component to the renaturation of distantly related single copy sequences to form a highly mismatched duplex DNAs with an average length of about 100 base pairs.
人类单拷贝DNA在相对不严格的条件下（50摄氏度，0.36M钠离子）复性，形成两种具有不同热稳定性的组分：一种高温组分在预期的双链良好配对温度（81摄氏度，0.18M钠离子）下解链，另一种低温组分在55摄氏度（0.18M钠离子）下解链。已研究高温和低温组分的产生与Cot（浓度与时间的乘积，单位为摩尔每秒每升）值和复性温度的关系。所形成的双链体已通过其对S1核酸酶的抗性进行表征，其长度已通过凝胶电泳确定。这些实验及相关对照的结果表明，低温组分不是DNA片段长度、非特异性碱基配对或羟基磷灰石层析条件造成的假象。我们将该组分的低热稳定性归因于远缘单拷贝序列的复性，从而形成平均长度约为100个碱基对的高度错配双链DNA。
