Fujiwara Satoru, Matsuo Tatsuhito, Sugimoto Yasunobu, Shibata Kaoru
Institute for Quantum Life Science , National Institutes for Quantum and Radiological Science and Technology , 2-4 Shirakata , Tokai , Ibaraki 319-1106 , Japan.
Nagoya University Synchrotron Radiation Research Center , Furo-cho, Chikusa-ku, Nagoya , Aichi 464-8603 , Japan.
J Phys Chem Lett. 2019 Dec 5;10(23):7505-7509. doi: 10.1021/acs.jpclett.9b03196. Epub 2019 Nov 25.
Characterization of the dynamics of disordered polypeptide chains is required to elucidate the behavior of intrinsically disordered proteins and proteins under non-native states related to the folding process. Here we develop a method using quasielastic neutron scattering, combined with small-angle X-ray scattering and dynamic light scattering, to evaluate segmental motions of proteins as well as diffusion of the entire molecules and local side-chain motions. We apply this method to RNase A under the unfolded and molten-globule (MG) states. The diffusion coefficients arising from the segmental motions are evaluated and found to be different between the unfolded and MG states. The values obtained here are consistent with those obtained using the fluorescence-based techniques. These results demonstrate not only feasibility of this method but also usefulness to characterize the behavior of proteins under various disordered states.
为了阐明内在无序蛋白质以及与折叠过程相关的非天然状态下蛋白质的行为，需要对无序多肽链的动力学进行表征。在此，我们开发了一种方法，该方法结合小角X射线散射和动态光散射，使用准弹性中子散射来评估蛋白质的片段运动以及整个分子的扩散和局部侧链运动。我们将此方法应用于处于未折叠和熔球态（MG）的核糖核酸酶A。评估了由片段运动产生的扩散系数，发现未折叠态和MG态之间存在差异。此处获得的值与使用基于荧光的技术获得的值一致。这些结果不仅证明了该方法的可行性，还证明了其在表征各种无序状态下蛋白质行为方面的有用性。
