Lindorff-Larsen Kresten, Best Robert B, Vendruscolo Michele
Department of Biochemistry, Institute of Molecular Biology and Physiology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen Ø, DK, Denmark.
J Biomol NMR. 2005 Aug;32(4):273-80. doi: 10.1007/s10858-005-8873-0.
The experimental determination of scalar three-bond coupling constants represents a powerful method to probe both the structure and dynamics of proteins. The detailed structural interpretation of such coupling constants is usually based on Karplus relationships, which allow the measured couplings to be related to the torsion angles of the molecules. As the measured couplings are sensitive to thermal fluctuations, the parameters in the Karplus relationships are better derived from ensembles representing the distributions of dihedral angles present in solution, rather than from single conformations. We present a method to derive such parameters that uses ensembles of conformations determined through dynamic-ensemble refinement--a method that provides structural ensembles that simultaneously represent both the structure and the associated dynamics of a protein.
标量三键耦合常数的实验测定是探测蛋白质结构和动力学的有力方法。此类耦合常数的详细结构解释通常基于卡尔普斯关系式，该关系式可将测得的耦合与分子的扭转角关联起来。由于测得的耦合对热涨落敏感，卡尔普斯关系式中的参数最好从代表溶液中存在的二面角分布的系综中推导得出，而非从单一构象中推导。我们提出一种推导此类参数的方法，该方法使用通过动态系综精修确定的构象系综——这是一种能提供同时代表蛋白质结构及其相关动力学的结构系综的方法。
