Читать книгу Chemistry and Biology of Non-canonical Nucleic Acids - Naoki Sugimoto - Страница 44

It is important to understand the stabilities of both canonical and non-canonical nucleic acids for estimating nucleic acid structures and functions in vitro and in cell. In this chapter, the stabilities of non-canonical nucleic acids are introduced with comparison of the difference from those of the canonical duplex. In general, the following factors play major roles in determining the stabilities of nucleic acids: hydrogen bonding, base stacking, conformational entropy, hydration, and cation binding. Hydrogen bonding, base stacking, and conformational stress are determined by sequence of nucleic acids [1]. In contrast, the water and cation bindings are determined by conditions surrounding the nucleic acid such as cosolute and cosolvent conditions that are described next in Chapter 4 in detail [2]. Thus, this chapter surveys the factors influencing the stabilities of nucleic acids depending on sequences and their environments. Moreover, this chapter describes methods that can be used to analyze quantitatively the stabilities of the nucleic acids. To understand the basic factors influencing stabilities of the nucleic acids, the stability of duplexes is explained, and then the non-canonical structures and their stability are described.