A kinetic analysis of cyanine selectivity: CCyan2 and Cyan40 intercalation into poly(dA–dT)·poly(dA–dT) and poly(dG–dC)·poly(dG–dC)

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• 作者：Tarita Biver ; Marco Pulzonetti ; Fernando Secco ; Marcella Venturini and Sergiy Yarmoluk
• 关键词：Cyanines ; Intercalation ; Kinetics ; Selectivity ; Poly(dA– ; dT)· ; poly(dA– ; dT) ; Poly(dG– ; dC)· ; poly(dG– ; dC)
• 刊名：Archives of Biochemistry and Biophysics
• 出版年：2006
• 期刊代码：116_00039861
• 类别：ch
• 出版时间：15 July 2006
• 卷：451
• 期：2
• 页码：103-111
• 文件大小：247 K

摘要

A T-jump investigation of the binding of Cyan40 [3-methyl-2-(1,2,6-trimethyl-4(1H)pyridinylidenmethyl)-benzothiazolium ion] and CCyan2 [3-methyl-2-[2-methyl-3-(3-methyl-2(3H)-benzothiazolylidene)-1-propenyl]-benzothiazolium ion] with poly(dA–dT)·poly(dA–dT) and poly(dG–dC)·poly(dG–dC) is performed at I = 0.1 M (NaCl), 25 °C and pH 7. Two kinetic effects are observed for both systems. The binding process is discussed in terms of the sequence D + P P,D PD_I PD_II, which leads first to fast formation of a precursor complex P,D and then to a partially intercalated complex PD_I which converts to the fully intercalate complex PD_II. Concerning CCyan2 the rate parameters depend on the polymer nature and their analysis shows that in the case of poly(dG–dC)·poly(dG–dC) the most stable bound form is the fully intercalated complex PD_II, whereas in the case of poly(dA–dT)·poly(dA–dT) the partially intercalated complex PD_I is the most stable species. Concerning Cyan40, the rate parameters remain unchanged on going from A–T to G–C indicating that this dye is unselective.