SINGLE-STRANDED OLIGOMERS AND POLYMERS OF CYTIDYLIC AND 2'-DEOXYCYTIDYLIC ACIDS - COMPARATIVE OPTICAL ROTATORY STUDIES
SINGLE-STRANDED OLIGOMERS AND POLYMERS OF CYTIDYLIC AND 2'-DEOXYCYTIDYLIC ACIDS - COMPARATIVE OPTICAL ROTATORY STUDIES
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DOI：
10.1073/pnas.57.2.423
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发表时间：
1967-01-01
影响因子：
11.1
通讯作者：
FASMAN, GD
中科院分区：
文献类型：
--
作者：
ADLER, A;GROSSMAN, L;FASMAN, GD
利用合成的多核苷酸作为RNA和DNA的模型最近受到了广泛的关注。证据，其中大部分是基于旋光色散（ORD）1检测的不对称二级结构，积累了重要的碱基堆积相互作用，以及氢键，在稳定RNA在水溶液中。剩下的问题之一是检查碳水化合物残基对大分子性质的影响，即比较核糖核苷酸与类似的脱氧核糖核苷酸的结构。在中性pH下，聚胞苷酸（poly-rC）以非质子化的单链螺旋结构存在。3 4这种构象与半质子化的双链5螺旋在酸性溶液中通过胞嘧啶-胞嘧啶氢键结合在一起的构象非常不同。单链poly-rC的性质可以通过考虑最近邻碱基堆积相互作用来计算。6类似地，聚脱氧胞苷酸（poly-dC）在滴定期间经历结构转变，尽管该聚合物在其滴定曲线和减色性7以及其与poly-rI 8和poly-rG的复合物的稳定性方面与poly-rC显著不同。9
The-use of synthetic polynucleotides as models for RNA and DNA has recently received much attention. Evidence, much of it based upon optical rotatory dispersion (ORD) 1 for detection of asymmetric secondary structures, has accumulated for the importance of base-stacking interactions, as well as for hydrogen bonding, in stabilizing RNA in aqueous solution. One of the remaining problems is to examine the effect of the carbohydrate residue upon macromolecular properties, that is, to compare the structure of ribonucleotides to those of the analogous deoxyribonucleotides.At neutral pH, polycytidylic acid (poly-rC) exists as a nonprotonated, 2 singlestranded helical structure. 3 4 This conformation is very different from the halfprotonated, double-stranded5 helix held together by cytosine-cytosine hydrogen bonds in acid solution. The properties of single-stranded poly-rC can be calculated fairly well from consideration of nearest-neighbor base-stacking interactions. 6 Similarly, polydeoxycytidylic acid (poly-dC) undergoes a structural transition during titration, although this polymer differs markedly from poly-rC in its titration curve and hypochromicity, 7 and in the stability of its complexes with poly-rI8 and with poly-rG. 9