NUCLEAR MAGNETIC RESONANCE STUDIES OF A PARAMAGNETIC METALLO DNA COMPLEX
NUCLEAR MAGNETIC RESONANCE STUDIES OF A PARAMAGNETIC METALLO DNA COMPLEX
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顺磁性金属 DNA 复合体的核磁共振研究
DOI：
10.1021/ja9633169
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
M. Gochin
中科院分区：
文献类型：
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作者：
M. Gochin
标准核磁共振（NMR）光谱学利用核Overhauser效应（NOE）获得质子间距离约束。与蛋白质相比，由于缺少中远程NOEs， RNA和DNA的结构相对不精确。理想情况下，需要远程约束来更精确地定义结构。我们在这里报告了一个由DNA寡聚物、药物和二价阳离子组成的三元顺磁配合物的核磁共振研究。本研究的目的是利用伪接触位移作为大分子溶液核磁共振的结构约束通过分配DNA络合物的顺磁谱，我们从金属离子获得了25 A的远程约束。该复合物由d(TTGGCCAA)2与两个在G4C5步骤的小凹槽中的chromomycin-A3 (I)分子结合组成。3-5单个Co2+阳离子与两个造色素的O1和O9原子以及两个水分子强结合，形成伪八面体配位位点的
Standard nuclear magnetic resonance (NMR) spectroscopy exploits the nuclear Overhauser effect (NOE) to obtain interproton distance restraints. Structures of RNA and DNA are relatively imprecisely determined, due to the shortage of medium and long-range NOEs compared to those of proteins. Longrange constraints are ideally needed to define the structures more precisely. We report here on the NMR study of a ternary paramagnetic complex consisting of a DNA oligomer, a drug, and a divalent cation. The purpose of the study is to utilize pseudocontact shifts as structural restraints in solution NMR of macromolecules.1,2 By assigning the paramagnetic spectrum of the DNA complex, we have obtained long-range constraints out to 25 A from the metal ion. The complex consists of d(TTGGCCAA)2 bound to two molecules of chromomycin-A3 (I) in the minor groove at the G4C5 step.3-5 A single Co2+ cation is strongly bound to the O1 and O9 atoms of two chromomycins and to two water molecules, forming a pseudo-octahedral coordination site.6 The