Department of Biochemistry, Duke University, 229, Nanaline Duke Building, 307 Research Drive, Durham, NC, 27710, USA.
Department of Chemistry, Duke University, Durham, NC, 27708, USA.
Angew Chem Int Ed Engl. 2020 Jul 6;59(28):11262-11266. doi: 10.1002/anie.202000493. Epub 2020 May 11.
Biomolecules undergo motions on the micro-to-millisecond timescale to adopt low-populated transient states that play important roles in folding, recognition, and catalysis. NMR techniques, such as Carr-Purcell-Meiboom-Gill (CPMG), chemical exchange saturation transfer (CEST), and R are the most commonly used methods for characterizing such transitions at atomic resolution under solution conditions. CPMG and CEST are most effective at characterizing motions on the millisecond timescale. While some implementations of the R experiment are more broadly sensitive to motions on the micro-to-millisecond timescale, they entail the use of selective irradiation schemes and inefficient 1D data acquisition methods. Herein, we show that high-power radio-frequency fields can be used in CEST experiments to extend the sensitivity to faster motions on the micro-to-millisecond timescale. Given the ease of implementing high-power fields in CEST, this should make it easier to characterize micro-to-millisecond dynamics in biomolecules.
生物分子在微秒到毫秒的时间尺度上发生运动，以形成低 populate 的瞬态状态，这些状态在折叠、识别和催化中发挥着重要作用。NMR 技术，如 Carr-Purcell-Meiboom-Gill (CPMG)、化学交换饱和转移 (CEST) 和 R 技术，是在溶液条件下以原子分辨率表征这些转变的最常用方法。CPMG 和 CEST 最适用于表征毫秒时间尺度上的运动。虽然 R 实验的一些实现方案对微秒到毫秒时间尺度上的运动更为敏感，但它们需要使用选择性辐照方案和效率低下的 1D 数据采集方法。在此，我们表明，可以在 CEST 实验中使用高功率射频场来扩展对微秒到毫秒时间尺度上更快运动的灵敏度。鉴于在 CEST 中实现高功率场的简便性，这应该使得在生物分子中表征微秒到毫秒时间尺度的动力学变得更加容易。
