Doornbos J, den Hartog J A, van Boom J H, Altona C
Eur J Biochem. 1981 May 15;116(2):403-12. doi: 10.1111/j.1432-1033.1981.tb05349.x.
In recent publications A2'-5'A2'-5'A was found to be an inhibitor of protein synthesis. In this research conformational analysis of the 2'-5'-linked nucleotides A2'-5'A, A2'-5'A2'-5'A and A2'-5'U is reported. The complete 1H-NMR assignment of the three compounds is given. The degree and mode of base-base stacking is extracted from coupling constant data and circular dichroic (CD) spectra at various temperatures. The 2'-5' nucleotides surprisingly show a much stronger tendency to stack than the 3'-5' compounds. At 85 degrees C A2'-5'A occurs for about 50% in stacked states. The mode of stacking is different from 3'-5'ribonucleotides where the sugar rings predominantly adopt an N conformation. A2'-5'U displays an A(S)2'-5'U(N) stacked state. In A2'-5'A 'mixed' modes of stacking, i.e. NN, NS, SN and SS, are proposed to account for the CD and NMR observations.
在最近的出版物中，发现2'-5'连接的寡腺苷酸（A2'-5'A、A2'-5'A2'-5'A）是蛋白质合成的抑制剂。本研究报道了2'-5'连接的核苷酸A2'-5'A、A2'-5'A2'-5'A和A2'-5'U的构象分析。给出了这三种化合物完整的1H-NMR归属。通过耦合常数数据和不同温度下的圆二色（CD）光谱，得出碱基堆积的程度和模式。令人惊讶的是，2'-5'核苷酸比3'-5'化合物表现出更强的堆积倾向。在85℃时，A2'-5'A约50%处于堆积状态。其堆积模式不同于3'-5'核糖核苷酸，后者的糖环主要呈N构象。A2'-5'U呈现A(S)2'-5'U(N)堆积状态。在A2'-5'A中，提出“混合”堆积模式，即NN、NS、SN和SS模式，以解释CD和NMR观测结果。
