Mehta M A, Gregory D M, Kiihne S, Mitchell D J, Hatcher M E, Shiels J C, Drobny G P
Department of Chemistry, University of Washington, Seattle 98195, USA.
Solid State Nucl Magn Reson. 1996 Dec;7(3):211-28. doi: 10.1016/s0926-2040(96)01267-2.
A windowless, homonuclear dipolar recoupling pulse sequence (DRAWS) is described and a theoretical basis for describing its recoupling performance is developed using numerical techniques. It is demonstrated that DRAWS recouples weak dipolar interactions over a broad range of experimental and molecular conditions. We discuss two spectroscopic control experiments, which help to take into account effects due to insufficient proton decoupling, relaxation, and static dipolar couplings to nearby 13C spins at natural abundance. Finally DRAWS is used in combination with selective 13C labeling to measure 13C-13C distances in five doubly labeled DNA dodecamers, [d(CGCGAATTCGCG)]2, which contain the binding site for the restriction enzyme EcoRI. The longest distance reported is 4.8 A. In most cases the distances agree well with those derived from X-ray crystallographic data, although small changes in hydration level can result in relatively large changes in internuclear distances.
本文描述了一种无窗同核偶极重耦合脉冲序列（DRAWS），并运用数值技术建立了描述其重耦合性能的理论基础。结果表明，DRAWS能在广泛的实验和分子条件下重耦合弱偶极相互作用。我们讨论了两个光谱控制实验，这有助于考虑由于质子去耦不足、弛豫以及在天然丰度下与附近13C自旋的静态偶极耦合所产生的影响。最后，DRAWS与选择性13C标记结合使用，以测量五个双标记DNA十二聚体[d(CGCGAATTCGCG)]2中的13C-13C距离，该十二聚体包含限制性内切酶EcoRI的结合位点。报道的最长距离为4.8 Å。在大多数情况下，这些距离与从X射线晶体学数据得出的距离吻合良好，尽管水合水平的微小变化可能导致核间距离发生相对较大的变化。
