Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, 1121 Budapest, Hungary.
Research Centre for Natural Sciences, Institute of Enzymology, 1117 Budapest, Hungary.
Biomolecules. 2021 May 18;11(5):757. doi: 10.3390/biom11050757.
The amount of bonds between constituting parts of a protein aggregate were determined in wild type (WT) and A53T α-synuclein (αS) oligomers, amyloids and in the complex of thymosin-β-cytoplasmic domain of stabilin-2 (Tβ-stabilin CTD). A53T αS aggregates have more extensive βsheet contents reflected by constant regions at low potential barriers in difference (to monomers) melting diagrams (s). Energies of the intermolecular interactions and of secondary structures bonds, formed during polymerization, fall into the 5.41 kJ mol ≤ ≤ 5.77 kJ mol range for αS aggregates. Monomers lose more mobile hydration water while forming amyloids than oligomers. Part of the strong mobile hydration water-protein bonds break off and these bonding sites of the protein form intermolecular bonds in the aggregates. The new bonds connect the constituting proteins into aggregates. Amyloid-oligomer difference showed an overall more homogeneous solvent accessible surface of A53T αS amyloids. From the comparison of the nominal sum of the s of the constituting proteins to the measured of the Tβ-stabilin CTD complex, the number of intermolecular bonds connecting constituent proteins into complex is 20(1) HO/complex. The energies of these bonds are in the 5.40(3) kJ mol ≤ ≤ 5.70(5) kJ mol range.
蛋白质聚集体组成部分之间的键合数量在野生型 (WT) 和 A53T α-突触核蛋白 (αS) 寡聚物、淀粉样蛋白以及胸腺肽-β-稳定素 2 胞质结构域 (Tβ-稳定素 CTD) 复合物中进行了测定。A53T αS 聚集体具有更广泛的β-折叠含量，这反映在低势垒差异 (与单体相比) 融解图 (s) 中的恒区。聚合过程中形成的分子间相互作用能和二级结构键能落入 5.41 kJ mol ≤ ≤ 5.77 kJ mol 范围内。单体在形成淀粉样蛋白时比寡聚物失去更多的可移动水合水。一部分强可移动水合蛋白质键断裂，这些蛋白质的结合部位在聚集体中形成分子间键。新键将组成蛋白质连接成聚集体。淀粉样蛋白-寡聚物差异表明 A53T αS 淀粉样蛋白的溶剂可及表面积总体上更均匀。从组成蛋白质的 s 的标称总和与 Tβ-稳定素 CTD 复合物的实测 进行比较，将组成蛋白质连接成复合物的分子间键的数量为 20(1) HO/复合物。这些键的能量在 5.40(3) kJ mol ≤ ≤ 5.70(5) kJ mol 范围内。
