(J. Magn. Reson., 2016, 272, 46–52)
我们建立了一种新的频率选择性异核偶极重耦方法DBP，用于实现15N-13C极化转移。相对于DCP (ramp DCP或SPECIFIC CP)方法，我们的方法可有效地避免运动对传递效率的影响，有利于蛋白质中运动性较强的残基或片段的研究。在实验上，该方法非常稳定、设置简便。此外，该方法还可以用于13C-31P、15N-31P和31P-29Si等自旋1/2核之间的相关实验。 该方法以及后续研究的报道发布在《波谱学杂志》微信公众号上。
图1. 用于二维15N-13C相关实验的DBP(Dual back-to-back Pulses)脉冲序列
Band-selective heteronuclear dipolar recoupling with dual back-to-back pulses in rotating solids
Abstract We propose a robust band-selective heteronuclear 15N-13C recoupling method using dual back-to-back (BABA) pulses (DBP). It contains four 90° pulses in each rotor period and corresponding phase cycling on each channel (13C and 15N). DBP aims at rapid band-selective heteronuclear magnetization transfer between 15N and 13Cα/13C’, whose efficiency is close to that of the well-known SPECIFIC CP in membrane proteins with relatively short relaxation time in rotating frame (T1ρ). Compared to SPECIFIC CP, DBP is very simple to set up and highly robust to RF variations. Thus, it can reduce the efforts in experimental optimization, especially for low-sensitive samples, and is very suitable for long-time or quantitative experiments. The efficacy of DBP is demonstrated by the E. coli diacylglycerol kinase (DAGK) proteoliposome. We anticipate that DBP would be useful for (segments of) membrane proteins that undergo the μs-ms timescale motions in magic-angle spinning (MAS) solid-state NMR.