Chary K V, Hosur R V, Govil G, Chen C Q, Miles H T
Chemical Physics Group, Tata Institute of Fundamental Research, Bombay, India.
Biochemistry. 1988 May 17;27(10):3858-67. doi: 10.1021/bi00410a050.
Complete resonance assignments of nonexchangeable base protons and sugar protons in d-GGTACGCGTACC at 500 MHz have been obtained by two-dimensional correlated spectroscopy (COSY) and nuclear Overhauser enhancement spectroscopy (NOESY). The characteristic phase-sensitive multiplet patterns of the ntrasugar cross peaks in the omega 1-scaled COSY spectrum have been used to estimate several scalar coupling constants (J). These coupling constants combined with the intranucleotide COSY cross peak intensities have been used to identify the sugar pucker of individual nucleotide units. In most cases, the deoxyribose rings adopt a conformation close to O4'-endo. Spin-diffusion has been monitored from the buildup of the normalized volumes of NOE cross peaks in NOESY spectra as a function of mixing time. A set of 55 intranucleotide and internucleotide interproton distances have been estimated from the low mixing time NOESY spectrum (tau m = 75 ms). The estimated intranucleotide proton-proton distances have been used to determine the individual glycosidic dihedral angles of the nucleotide units which lie in the anti domain. It is observed that the molecule adopts an overall conformation close to that of the B-form although there are differences in the intricate details.
通过二维相关光谱（COSY）和核Overhauser增强光谱（NOESY），已获得500 MHz下d-GGTACGCGTACC中不可交换碱基质子和糖质子的完整共振归属。ω1标度的COSY谱中糖内交叉峰的特征性相敏多重峰模式已用于估算几个标量耦合常数（J）。这些耦合常数与核苷酸内COSY交叉峰强度相结合，已用于确定各个核苷酸单元的糖折叠。在大多数情况下，脱氧核糖环采用接近O4'-内型的构象。通过监测NOESY谱中NOE交叉峰归一化体积随混合时间的增加来观察自旋扩散。已从低混合时间NOESY谱（τm = 75 ms）估算出一组55个核苷酸内和核苷酸间的质子间距离。估算出的核苷酸内质子-质子距离已用于确定位于反式结构域的核苷酸单元的各个糖苷二面角。观察到该分子整体构象接近B型，尽管在复杂细节上存在差异。
