Bellissent-Funel M C, Filabozzi A, Chen S H
Laboratoire Léon Brillouin (CEA-CNRS), CE-Saclay, Gif-sur-Yvette, France.
Biophys J. 1997 Apr;72(4):1792-9. doi: 10.1016/S0006-3495(97)78825-8.
Quasielastic neutron scattering measurements of dry and 35% D2O hydrated amorphous protein powder of C-phycocyanin were made as a function of temperature ranging from 313K down to 100K. The protein is grown from blue-green algae cultured in D2O and is deuterated up to 99%. The scattering is thus dominated by coherent scattering. Within the best energy resolution of the time-of-flight instrument, which is 28 mueV FWHM, the scattering appears entirely elastic. For this reason we are able to extract a coherent Debye-Waller factor by making an independent measurement of the static structure factor. We observe a considerable difference in the q dependence of the Debye-Waller factor between the dry and hydrated proteins; furthermore, there is an interesting temperature dependence of the Debye-Waller factor that is quite different from that predicted for dense hard-sphere liquids.
对干燥的以及35% D₂O水合的藻蓝蛋白非晶态蛋白质粉末进行了准弹性中子散射测量，测量结果是温度在313K至100K范围内的函数。该蛋白质由在D₂O中培养的蓝绿藻生长而来，氘化率高达99%。因此，散射主要由相干散射主导。在飞行时间仪器的最佳能量分辨率（半高宽为28 μeV）范围内，散射看起来完全是弹性的。基于这个原因，我们能够通过对静态结构因子进行独立测量来提取相干德拜-瓦勒因子。我们观察到干燥蛋白质和水合蛋白质的德拜-瓦勒因子对q的依赖性存在显著差异；此外，德拜-瓦勒因子存在有趣的温度依赖性，这与对致密硬球液体的预测有很大不同。
