UPR 9003 du CNRS, Ecole Supérieure de Biotechnologie de Strasbourg, Bld. Sébastien Brant, F-67400, Illkirch, France.
J Biomol NMR. 1999 Jan;13(1):83-8. doi: 10.1023/A:1008323420405.
Spectral density mapping provides direct access to protein dynamics with no assumptions as to the nature of the molecule or its dynamic behaviour. Reduced spectral density mapping characterises a protein's motions at a lower experimental burden, assuming that the spectral density function J(ω) is flat around ωH. This introduces little error for 15N relaxation data but is less valid for 13C studies, perturbing J(ωC) considerably to an extent that depends on the nature of the molecule's motions. We propose the fitting of spectral density at high frequencies to a single Lorentzian and show that the true values of the spectral density lie between those determined by the two approximations.
谱密度映射提供了一种直接获取蛋白质动力学信息的方法，无需对分子的性质或其动态行为做出任何假设。简化谱密度映射在实验负担较低的情况下描述蛋白质的运动，假设谱密度函数 J(ω) 在 ωH 周围是平坦的。对于 15N 弛豫数据，这种方法引入的误差很小，但对于 13C 研究的适用性较差，会极大地改变 J(ωC)，具体程度取决于分子运动的性质。我们建议对高频谱密度进行拟合，得到一个单洛伦兹函数，并表明真实的谱密度值介于这两种近似值之间。
