Tjandra N, Omichinski J G, Gronenborn A M, Clore G M, Bax A
Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA.
Nat Struct Biol. 1997 Sep;4(9):732-8. doi: 10.1038/nsb0997-732.
Anisotropy of the molecular magnetic susceptibility gives rise to a small degree of alignment. The resulting residual dipolar couplings, which can now be measured with the advent of higher magnetic fields in NMR, contain information on the orientation of the internuclear vectors relative to the molecular magnetic susceptibility tensor, thereby providing information on long range order that is not accessible by any of the solution NMR parameters currently used in structure determination. Thus, the dipolar couplings constitute unique and powerful restraints in determining the structures of magnetically oriented macromolecules in solution. The method is demonstrated on a complex of the DNA-binding domain of the transcription factor GATA-1 with a 16 base pair oligodeoxyribonucleotide.
分子磁化率的各向异性会产生一定程度的排列。随着核磁共振中更高磁场的出现，现在可以测量由此产生的残余偶极耦合，它包含了核间矢量相对于分子磁化率张量的取向信息，从而提供了目前用于结构测定的任何溶液核磁共振参数都无法获得的关于长程有序的信息。因此，偶极耦合在确定溶液中磁性取向大分子的结构方面构成了独特而强大的限制。该方法在转录因子GATA-1的DNA结合结构域与16个碱基对的寡脱氧核糖核苷酸的复合物上得到了验证。
