Kinetic studies on acridine orange-DNA interaction. A branched mechanism involving intercalation and outside "dimerization".
Kinetic studies on acridine orange-DNA interaction. A branched mechanism involving intercalation and outside "dimerization".
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吖啶橙-DNA相互作用的动力学研究。
DOI：
10.1093/oxfordjournals.jbchem.a129839
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发表时间：
1972
期刊：
影响因子：
--
通讯作者：
K. Akasaka
中科院分区：
文献类型：
--
作者：
M. Sakoda;K. Hiromi;K. Akasaka
采用荧光停流技术对吖啶橙（AO）与dna的相互作用进行了动力学研究。该技术直接跟踪了AO在DNA外部“二聚化”的动态过程和嵌入过程。每个过程的弛豫时间τ的浓度依赖性表明，它们本质上都是单分子过程，之前是双分子性质的快速预平衡，这被认为是AO分子与DNA外部磷酸基的随机结合。这证实了。我们先前提出的分支相互作用机制：其中（AO）x表示由下标x指定的AO分子的结合态。此外，随着p /比值的增加，二聚化的1/τ显著降低。这一结果表明，所观察到的二聚化是由随机结合的AO分子重排引起的，这可以看作是AO单体在由dna -磷酸盐规则排列形成的静电电位槽中的一维随机行走。另一方面，随着p / ratio的降低，嵌入过程的1/τ降低，这表明在低p / ratio下，结合二聚体的存在大大延缓了嵌入过程。
The fluorescence stopped-flow technique was applied to kinetic studies on the acridine orange (AO)-DNA interaction. The dynamic process of “dimerization“ of AO on the outside of DNA as well as the process of intercalation was directly followed with this technique. The concentration dependence of the relaxation time τ of each process suggests that both of them are essentially unimolecular processes preceded by a rapid pre-equilibrium of bimolecular nature, which is considered to be a random binding of AO molecules to the outside phosphate groups of DNA. This confirmed. our earlier suggestion of a branched mechanism of interaction: where (AO)xdenotes the bound state ot AO molecule specified by the subscriptx. In addition, a remarkable decrease of 1/τ for dimerization with theP/Dratio was observed. This result suggests that the observed dimerization is brought about by a rearrangement of randomly bound AO molecules, which may be regarded as a one dimensional random walk of AO monomers in an electrostatic potential trough formed by the regular array of DNA-phosphates. On the other hand, a decrease of 1/τ with decreasingP/Dratio was observed for intercalation, which indicates that the process of intercalation is considerably retarded by the presence of bound dimers at lowP/Dratios.