Kinetic and hydrodynamic studies of the complex of proflavine with poly A·poly U
Kinetic and hydrodynamic studies of the complex of proflavine with poly A·poly U
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普黄素与聚A·聚U复合物的动力学和流体动力学研究
DOI：
10.1002/bip.360100304
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发表时间：
1971
期刊：
影响因子：
2.9
通讯作者：
D. Crothers
中科院分区：
文献类型：
--
作者：
D. E. V. Schmechel;D. Crothers
松弛动力学实验揭示了原黄素与聚A·聚U和DNA的结合机制之间的普遍相似性。但在细节上存在差异。例如，前者的速率常数大约小一个数量级，并且各个步骤的热力学参数也不同。在这两种情况下，游离染料嵌入的总热量和自由能非常相似。与 DNA 的情况一样，相当多的染料（高达结合形式的 25%）附着在双螺旋的外部，即使在等温线的强结合区域也是如此。对聚 A·聚 U 的小棒状片段的沉降测量表明，结合原黄素的长度增加与 DNA 的长度增加相似。在松弛测量表明外部结合染料比例较高的条件下（高温），这种长度增加似乎变得更小。
Relaxation kinetic experiments reveal general similarity between the mechanism of binding of proflavine to poly A·poly U and DNA. There are differences in detail, however. For example, the rate constants are roughly an order of magnitude smaller for the former, and the thermodynamic parameters of the individual steps are also different. The total heat and free energy for intercalation of free dye are quite similar in the two cases. As was the case with DNA, considerable dye (up to 25% of the bound form) is attached externally to the double helix, even in the strong binding region of the isotherm. Sedimentation measurements on small, rodlike fragments of poly A·poly U reveal a length increase on binding proflavine of a magnitude similar to that found with DNA. This length increase seems to become smaller under conditions (high temperature) where the relaxation measurements indicate a higher fraction of externally bound dye.