Garriga P, Garcia-Quintana D, Manyosa J
Department de Bioquímica i de Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Eur J Biochem. 1992 Nov 15;210(1):205-10. doi: 10.1111/j.1432-1033.1992.tb17409.x.
Self-deconvolution and the fourth derivative of ultraviolet absorption spectra have been used to study stacked single-stranded and double-helix structures of different cytosine-containing polynucleotides for the first time. These compounds were studied under different solution conditions (pH and organic solvents) and at low temperatures. The red shift of the lower band (B2u band plus possibly some n-->pi* transition) of the absorption spectra in the cytosine-containing polynucleotides and the appearance of new peaks in the deconvoluted and derivative spectra in the 280-310 nm region are attributed mainly to cytosine-cytosine stacking interactions. In particular, the fourth-derivative peaks at wavelengths higher than 290 nm can be associated to coupling of electronic transitions of cytosine bases. The nature of the electronic transitions producing the absorption bands which are resolved in the aforementioned fourth-derivative peaks is discussed. It is concluded that the resolution-enhancement techniques used in this work, i.e. self-deconvolution and fourth derivative, complement each other and are useful methods to study structural changes of single-stranded and double-stranded polynucleotides allowing, at the same time, more information to be obtained about specific stacking interactions than classical absorption spectrophotometry.
自去卷积和紫外吸收光谱的四阶导数首次被用于研究不同含胞嘧啶多核苷酸的堆积单链和双螺旋结构。这些化合物在不同的溶液条件（pH值和有机溶剂）下以及低温下进行了研究。含胞嘧啶多核苷酸吸收光谱中较低波段（B2u波段加上可能的一些n→π*跃迁）的红移以及在280 - 310 nm区域去卷积光谱和导数光谱中出现的新峰，主要归因于胞嘧啶 - 胞嘧啶堆积相互作用。特别是，波长高于290 nm处的四阶导数峰可能与胞嘧啶碱基的电子跃迁耦合有关。讨论了产生上述四阶导数峰中分辨出的吸收带的电子跃迁的性质。得出的结论是，本工作中使用的分辨率增强技术，即自去卷积和四阶导数，相互补充，是研究单链和双链多核苷酸结构变化的有用方法，与传统吸收分光光度法相比，同时能够获得更多关于特定堆积相互作用的信息。
