Potaman V N, Bannikov Y A, Shlyachtenko L S
Nucleic Acids Res. 1980 Feb 11;8(3):635-42. doi: 10.1093/nar/8.3.635.
Sedimentation of DNA ethanol-water solutions has been studied over the range of ethanol concentrations corresponding to the B to A transition (65-80% ethanol, v/v). High ethanol concentrations (more than 75%) have been found to promote aggregate formation in solution. The molecular weight of DNA under fixed ionic conditions in solution (5x10(-4)M NaCl) has been shown to influence the value of ethanol concentration at which aggregates appear. On the other hand, the fact that DNA molecular weight has not been found to exert any influence on B to A transition curves obtained from CD measurements suggests that the changes observed in DNA CD spectra on adding ethanol to the solution are independent of aggregate formation. The date obtained show that, first, aggregation is not a necessary condition for the DNA transition from the B to the A-conformation and, second, changes in CD spectra of DNA under the influence of ethanol are not related to the process of aggregation.
在对应于B型到A型转变的乙醇浓度范围内(65 - 80%乙醇,体积/体积),对DNA乙醇 - 水溶液的沉降进行了研究。已发现高乙醇浓度(超过75%)会促进溶液中聚集体的形成。在固定离子条件下(5×10⁻⁴M NaCl)溶液中DNA的分子量已被证明会影响聚集体出现时的乙醇浓度值。另一方面,未发现DNA分子量对通过圆二色性(CD)测量获得的B型到A型转变曲线有任何影响,这表明向溶液中添加乙醇时DNA CD光谱中观察到的变化与聚集体形成无关。所获得的数据表明,首先,聚集体形成不是DNA从B型构象转变为A型构象的必要条件,其次,乙醇影响下DNA的CD光谱变化与聚集体形成过程无关。