Torrence P F, De Clercq E, Witkop B
Biochemistry. 1976 Feb 24;15(4):724-34. doi: 10.1021/bi00649a002.
By the techniques of interferon induction in primary rabbit kidney cells "superinduced" with metabolic inhibitors, ultraviolet absorbance-temperature profiles, sensitivity to pancreatic ribonuclease A, and sucrose velocity gradient ultracentrifugation, a number of reactions between double-helical RNA and single-stranded RNA or DNA homopolymers were investigated. The polymers involved in these studies were poly(adenylic acid), poly(uridylic acid), poly(ribothymidylic acid), poly(5-bromouridylic acid), poly(deoxythymidylic acid), poly(deoxyuridylic acid), poly(3-methyluridylic acid), poly(2'-O-methyluridylic acid), and poly(2'-azido-2'-deoxyuridylic acid). Two different reaction courses, both leading to the formation of triple helices, were noted: (1) poly(Ux)-poly(A) + poly(Uy) leads to poly(Ux)-poly(A)-poly(Uy) if the Tm of poly(Ux)-poly(A) was higher than the Tm of poly(Uy)-poly(A); (2) poly(Ux)-poly(A) + poly(Uy) leads to poly(Uy)-poly(A)-poly(Ux) if the Tm of poly(Ux)-poly(A) was lower than the Tm of poly(Uy)-poly(A). In these equations, the homopolymer written to the left of poly(A) implies Watson-Crick hydrogen bonding whereas the polymer to the right of poly(A) is involved in Hoogsteen hydrogen bonding.
通过在原代兔肾细胞中用代谢抑制剂“超诱导”干扰素的技术、紫外吸收-温度曲线、对胰核糖核酸酶A的敏感性以及蔗糖速度梯度超速离心法，研究了双链RNA与单链RNA或DNA同聚物之间的一些反应。这些研究中涉及的聚合物有聚腺苷酸、聚尿苷酸、聚核糖胸苷酸、聚5-溴尿苷酸、聚脱氧胸苷酸、聚脱氧尿苷酸、聚3-甲基尿苷酸、聚2'-O-甲基尿苷酸和聚2'-叠氮-2'-脱氧尿苷酸。注意到两种不同的反应过程，两者均导致三链螺旋的形成：（1）如果聚（Ux）-聚（A）的解链温度高于聚（Uy）-聚（A）的解链温度，则聚（Ux）-聚（A）+聚（Uy）会生成聚（Ux）-聚（A）-聚（Uy）；（2）如果聚（Ux）-聚（A）的解链温度低于聚（Uy）-聚（A）的解链温度，则聚（Ux）-聚（A）+聚（Uy）会生成聚（Uy）-聚（A）-聚（Ux）。在这些等式中，写在聚（A）左侧的同聚物意味着沃森-克里克氢键，而聚（A）右侧的聚合物参与了 hoogsteen 氢键。
