当前位置: X-MOL 学术ChemPhysChem › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Self-Assembly of DNA and RNA Building Blocks Explored by Nitrogen-14 NMR Crystallography: Structure and Dynamics.
ChemPhysChem ( IF 2.3 ) Pub Date : 2020-04-07 , DOI: 10.1002/cphc.201901214
Diego Carnevale 1 , Marcel Hollenstein 2 , Geoffrey Bodenhausen 1
Affiliation  

The isotopic enrichment of nucleic acids with nitrogen‐15 is often carried out by solid‐phase synthesis of oligonucleotides using phosphoramidite precursors that are synthetically demanding and expensive. These synthetic challenges, combined with the overlap of chemical shifts, explain the lag of nitrogen‐15 NMR studies of nucleic acids behind those of proteins. For the structural characterization of DNA and RNA‐related systems, new NMR methods that exploit the naturally occurring 99.9 % abundant nitrogen‐14 isotope are therefore highly desirable. In this study, we have investigated nitrogen‐14 spectra of self‐assembled quartets based on the nucleobase guanine in the solid state by means of magic‐angle spinning NMR spectroscopy. The network of dipolar proton–nitrogen couplings between neighboring stacked purine units is probed by 2D spectra based on 1H→14N→1H double cross‐polarization. Interplane dipolar contacts are identified between the stacked G quartets. The assignment is supported by density functional theory (DFT) calculations of the anisotropic chemical shifts and quadrupolar parameters. The experimental spectra are fully consistent with internuclear distances obtained in silico. Averaging of chemical shifts due to internal motions can be interpreted by semiempirical calculations. This method can easily be extended to synthetic G quartets based on nucleobase or nucleoside analogs and potentially to oligonucleotides.

中文翻译:

Nitrogen-14 NMR晶体学探索的DNA和RNA构建基块的自组装:结构和动力学。

用氮-15富集核酸的同位素通常是通过使用合成要求高且昂贵的亚磷酰胺前体通过固相合成寡核苷酸来进行的。这些合成的挑战,再加上化学位移的重叠,解释了核酸的15级NMR的15级NMR研究落后于蛋白质的水平。因此,对于DNA和RNA相关系统的结构表征,非常需要利用天然存在的99.9%丰富的氮14同位素的新NMR方法。在这项研究中,我们通过魔角旋转NMR光谱法研究了基于固态核碱基鸟嘌呤的自组装四重奏的14个氮谱。1 H→ 14 N→ 1 H双交叉极化。在堆叠的G四重奏之间确定了平面间偶极接触。这种分配得到各向异性化学位移和四极参数的密度泛函理论(DFT)计算的支持。实验光谱与在计算机中获得的核间距离完全一致。可以通过半经验计算来解释由于内部运动引起的化学位移的平均值。这种方法可以很容易地扩展到基于核碱基或核苷类似物的合成G四重奏,并可能扩展到寡核苷酸。
更新日期:2020-04-07
down
wechat
bug