Influence of cyanine dye structure on self-aggregation and interaction with nucleic acids: A kinetic approach to TO and BO binding
Influence of cyanine dye structure on self-aggregation and interaction with nucleic acids: A kinetic approach to TO and BO binding
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DOI：
10.1016/j.abb.2007.04.034
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发表时间：
2007-09-01
影响因子：
3.9
通讯作者：
Yarnaoluk, Sergiy
中科院分区：
文献类型：
--
作者：
Biver, Tarita;Boggioni, Alessia;Yarnaoluk, Sergiy
研究了25 ℃、pH 7条件下菁染料噻唑橙子（TO）和苯并噻唑橙子（BO）自聚集与CTDNA结合的动力学和平衡。吸收光谱和T-跳跃实验表明，BO形成J-聚集体，而TO形成更稳定的H-聚集体。荧光和吸光度滴定表明TO比BO更紧密地结合DNA。对于低聚合物与染料浓度比（C-P/C-D），TO在外部堆叠到DNA，而对于高CP/CD值，发生染料嵌入。在高CP/CD下进行的T-跳跃和停流实验与反应方案D+S可逆箭头D，S可逆箭头：DSI可逆箭头DSII一致，其中前体络合物D，S演变为部分嵌入的络合物DS，其转化为更稳定的嵌入物DSII。非静电力在D，S稳定中起主要作用。两种染料的最后一步相似，表明碱基对之间存在共同的苯并噻唑残基。使用聚（dA-dT）-聚（dA-dT）和聚（dG-dC）-聚（dG-dC）的实验证实了TO的碱基对偏好性。(c)2007年爱思唯尔公司All rights reserved.
Kinetics and equilibria of cyanine dyes thiazole orange (TO) and benzothiazole orange (BO) self-aggregation and binding to CTDNA are investigated in aqueous solution at 25 C and pH 7. Absorbance spectra and T-jump experiments reveal that BO forms J-aggregates while TO forms more stable H-aggregates. Fluorescence and absorbance titrations show that TO binds to DNA more tightly than BO. TO stacks externally to DNA for low polymer-to-dye concentration ratios (C-P/C-D) while dye intercalation occurs for high values of CP/CD. T-jump and stopped-flow experiments performed at high CP/CD agree with reaction scheme D+S reversible arrow D,S reversible arrow: DSI reversible arrow DSII where the precursor complex D,S evolves to a partially intercalated complex DS, which converts to the more stable intercalate DSII. Non-electrostatic forces play a major role in D,S stabilization. Last step is similar for both dyes suggesting accommodation of the common benzothiazole residue between base pairs. Experiments using poly(dA-dT)-poly(dA-dT) and poly(dG-dC)-poly(dG-dC) confirm base pair preference for TO. (c) 2007 Elsevier Inc. All rights reserved.