Perticaroli Stefania, Nickels Jonathan D, Ehlers Georg, Mamontov Eugene, Sokolov Alexei P
Joint Institute for Neutron Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
J Phys Chem B. 2014 Jul 3;118(26):7317-26. doi: 10.1021/jp503788r. Epub 2014 Jun 23.
The emergence of intrinsically disordered proteins (IDPs) as a recognized structural class has forced the community to confront a new paradigm of structure, dynamics, and mechanical properties for proteins. We present novel data on the similarities and differences in the dynamics and nanomechanical properties of IDPs and other biomacromolecules on the picosecond time scale. An IDP, β-casein (CAS), has been studied in a calcium bound and unbound state using neutron and light scattering techniques. We show that CAS partially folds and stiffens upon calcium binding, but in the unfolded state, it is softer than folded proteins such as green fluorescence protein (GFP). We also see that some localized diffusive motions in CAS have a larger amplitude than in GFP at this time scale but are still smaller than those observed in tRNA. In spite of these differences, CAS dynamics are consistent with the classes of motions seen in folded protein on this time scale.
内在无序蛋白（IDP）作为一种被认可的结构类别出现，迫使科学界面对蛋白质结构、动力学和机械性能的新范式。我们展示了关于IDP与其他生物大分子在皮秒时间尺度上的动力学和纳米力学性质异同的新数据。使用中子和光散射技术，研究了处于钙结合和未结合状态的IDP——β-酪蛋白（CAS）。我们发现，CAS在钙结合时会部分折叠并变硬，但在未折叠状态下，它比诸如绿色荧光蛋白（GFP）等折叠蛋白更柔软。我们还发现，在这个时间尺度上，CAS中的一些局部扩散运动的幅度比GFP中的大，但仍小于在tRNA中观察到的幅度。尽管存在这些差异，但CAS的动力学与在这个时间尺度上折叠蛋白中观察到的运动类别是一致的。
