Laboratory of Chemical Physics, National Institute of Diabetes & Digestive & Kidney Diseases, Building 5, Room 126, National Institutes of Health, Bethesda, MD 20892-0520, USA.
J Magn Reson. 2011 Dec;213(2):442-5. doi: 10.1016/j.jmr.2011.08.003. Epub 2011 Aug 31.
Three-dimensional triple resonance experiments have become an integral part of virtually every solution NMR study of proteins. The approach relies on uniform isotopic enrichment of proteins with (13)C and (15)N, and establishes the scalar connectivity pathway between nuclei through the large (1)J(NH), (1)J(CH)(, 1)J(CC), and (1)J(CN) couplings. The magnetization transfer process takes place through multiple, efficient one-bond magnetization transfer steps, rather than a single step through the smaller and variable (3)J(HH) couplings. The relatively large size and good uniformity of the one-bond couplings allowed the design of efficient magnetization transfer schemes that are effectively uniform across a given protein, nearly independent of conformation. Although conceptually straightforward, practical implementation of three-dimensional triple resonance experiments on proteins originally posed serious challenges. This account provides a personal perspective on some of the historical background to this work, the problems encountered as well as their solutions, and their evolution into today's standard arsenal of experiments.
三维三共振实验已经成为几乎每一个蛋白质溶液 NMR 研究不可或缺的一部分。该方法依赖于用 (13)C 和 (15)N 对蛋白质进行均匀的同位素富集，并通过大的 (1)J(NH)、(1)J(CH)、(1)J(CC) 和 (1)J(CN) 偶合建立核之间的标量连接途径。磁化转移过程通过多个有效的单键磁化转移步骤发生，而不是通过较小且变化的 (3)J(HH) 偶合进行单步转移。单键偶合的相对较大尺寸和良好的均匀性允许设计有效的磁化转移方案，这些方案在给定的蛋白质中几乎是均匀的，几乎与构象无关。尽管从概念上讲很简单，但最初在蛋白质上实现三维三共振实验确实存在一些挑战。本文从个人角度介绍了这项工作的一些历史背景、遇到的问题及其解决方案，以及它们如何演变成今天的标准实验库。
