Ferrage Fabien
Département de chimie, Ecole normale supérieure et Laboratoire des Biomolécules, CNRS UMR 7203, Paris, Cedex, France.
Methods Mol Biol. 2012;831:141-63. doi: 10.1007/978-1-61779-480-3_9.
Nitrogen-15 relaxation is the most ubiquitous source of information about protein (backbone) dynamics used by NMR spectroscopists. It provides the general characteristics of hydrodynamics as well as internal motions on subnanosecond, micro- and millisecond timescales of a biomolecule. Here, we present a full protocol to perform and analyze a series of experiments to measure the (15)N longitudinal relaxation rate, the (15)N transverse relaxation rate under an echo train or a single echo, the (15)N-(1)H dipolar cross-relaxation rate, as well as the longitudinal and transverse cross-relaxation rates due to the cross-correlation of the nitrogen-15 chemical shift anisotropy and the dipolar coupling with the adjacent proton. These rates can be employed to carry out model-free analyses and can be used to quantify accurately the contribution of chemical exchange to transverse relaxation.
氮-15弛豫是核磁共振光谱学家用于获取蛋白质（主链）动力学信息最普遍的来源。它能提供生物分子在亚纳秒、微秒和毫秒时间尺度上的流体动力学以及内部运动的一般特征。在此，我们展示了一套完整的方案，用于执行和分析一系列实验，以测量（15）N纵向弛豫率、回波串或单回波下的（15）N横向弛豫率、（15）N-（1）H偶极交叉弛豫率，以及由于氮-15化学位移各向异性与相邻质子的偶极耦合的交叉相关性所导致的纵向和横向交叉弛豫率。这些速率可用于进行无模型分析，并可用于准确量化化学交换对横向弛豫的贡献。
