Bustorff Nuno, Fitter Jörg
ER-C-3 Structural Biology & IBI-6 Cellular Structural Biology, Forschungszentrum Jülich, 52425 Jülich, Germany.
AG Biophysik, I. Physikalisches Institut (IA), RWTH Aachen University, 52074 Aachen, Germany.
Biomolecules. 2023 Aug 22;13(9):1280. doi: 10.3390/biom13091280.
A protein fold is defined as a structural arrangement of a secondary structure in a three-dimensional space. It would be interesting to know whether a particular fold can be assigned to certain features of the corresponding folding/unfolding transitions. To understand the underlying principles of the manifold folding transitions in more detail, single-molecule FRET is the method of choice. Taking the two-domain protein phosphoglycerate kinase (PGK) as an example, we investigated denaturant-induced unfolded states of PGK using the above method. For this purpose, different intramolecular distances within the two domains were measured. In addition to the known two-state transition, a transition with a compact folding intermediate was also identified in each of the two domains. Based on the structural homology of the domains (characterized by a Rossmann fold) and the striking similarity in the features of the measured distance changes during unfolding, clear evidence emerged that the underlying domain topology plays an important role in determining the observed structural changes.
蛋白质折叠被定义为二级结构在三维空间中的一种结构排列。了解特定的折叠是否可以归因于相应折叠/去折叠转变的某些特征将是很有趣的。为了更详细地理解多种折叠转变的潜在原理，单分子荧光共振能量转移是首选方法。以两结构域蛋白磷酸甘油酸激酶（PGK）为例，我们使用上述方法研究了变性剂诱导的PGK的未折叠状态。为此，测量了两个结构域内不同的分子内距离。除了已知的两态转变外，在两个结构域中的每一个中还鉴定出了具有紧密折叠中间体的转变。基于结构域的结构同源性（以罗斯曼折叠为特征）以及在去折叠过程中测量的距离变化特征的显著相似性，有明确证据表明潜在的结构域拓扑结构在决定观察到的结构变化中起重要作用。
