Busetta B, Picard P, Precigoux G
Unité de Biophysique Structurale (UMR 5471-CNRS), Université Bordeaux I, Talence, France.
J Pept Sci. 2001 Mar;7(3):121-7. doi: 10.1002/psc.300.
The possible influence of thermal motion on 1H chemical shifts is discussed for a small stable protein, the bovine pancreatic Kunitz trypsin inhibitor (BPTI). The thermal effects on the aromatic side chains and on the backbone are treated separately. The thermal motion of the aromatic side chains is accounted for in terms of their rotation around the C(alpha)-C(beta) bond and the motion of each individual proton is interpreted as a ratio between the amount of ordered and quite disordered states. The influence of hydrogen bonds is introduced as an extra contribution to the chemical shifts of the bonded proton. Their contribution to the chemical shifts resulting from the polarization of the peptide bond is investigated, as is their influence on local flexibility. Finally, the relative importance of each contribution to the chemical shift information is compared.
针对一种小型稳定蛋白质——牛胰Kunitz胰蛋白酶抑制剂（BPTI），讨论了热运动对¹H化学位移的可能影响。分别研究了热效应在芳香族侧链和主链上的情况。芳香族侧链的热运动通过其围绕C(α)-C(β)键的旋转来描述，每个质子的运动则被解释为有序态和无序态数量的比例。引入氢键对键合质子化学位移的额外贡献，研究了它们对肽键极化导致的化学位移的贡献，以及它们对局部柔韧性的影响。最后，比较了每种贡献对化学位移信息的相对重要性。
