Ogulchansky T Y, Losytskyy M Y, Kovalska V B, Lukashov S S, Yashchuk V M, Yarmoluk S M
Physics Department of Kyiv Taras Shevchenko National University, Ukraine.
Spectrochim Acta A Mol Biomol Spectrosc. 2001 Nov;57(13):2705-15. doi: 10.1016/s1386-1425(01)00537-6.
Spectral properties of carbocyanine dye 3-methyl-2-[3-methyl-2-(3-methyl-2,3-dihydro-1,3-benzothiazole-2-iliden)-1- butenyl]-1,3-benzothiazole-3-il iodide (Cyan betaiPr) in water solution, as well as in the presence of different types of double stranded DNA have been studied. While in water solution of 'free' dye Cyan betaiPr stays mainly in monomeric form, in the presence of DNA the dye molecules form J-aggregates. The molecular structure of these J-aggregates causes the Davydov splitting of their absorption band, corresponding to the first electronic transition. A study of site-specificity showed that in the presence of poly (dA/dT) the majority of Cyan betaiPr molecules form J-aggregates, while in the presence of poly (dGC/dGC) dye molecules stay mainly in monomeric form and in presence of chicken erythrocytes DNA both J-aggregate and monomeric forms of dye are present. We suppose that Cyan betaiPr molecules aggregate in DNA groove, which serves as a template for J-aggregate forming. An increase of ionic strength of solution leads to the release of dye molecules from DNA grooves and prevents J-aggregates formation.
研究了碳菁染料3-甲基-2-[3-甲基-2-(3-甲基-2,3-二氢-1,3-苯并噻唑-2-亚基)-1-丁烯基]-1,3-苯并噻唑-3-碘化物（Cyan betaiPr）在水溶液中以及在不同类型双链DNA存在下的光谱性质。在“游离”染料Cyan betaiPr的水溶液中，其主要以单体形式存在，而在DNA存在下，染料分子形成J-聚集体。这些J-聚集体的分子结构导致其吸收带出现达维多夫分裂，这对应于第一电子跃迁。位点特异性研究表明，在聚（dA/dT）存在下，大多数Cyan betaiPr分子形成J-聚集体，而在聚（dGC/dGC）存在下，染料分子主要以单体形式存在，在鸡红细胞DNA存在下，染料的J-聚集体和单体形式都存在。我们推测Cyan betaiPr分子在DNA凹槽中聚集，该凹槽作为J-聚集体形成的模板。溶液离子强度的增加导致染料分子从DNA凹槽中释放出来，并阻止J-聚集体的形成。
