Előadó: Bokor Mónika Zsuzsanna (SZFI)
Előadás címe: α-Synuclein proteins ― wide-line-NMR melting diagrams and secondary structure predictions
Dátum: Tuesday, 19 April 2022, 10:00
Helyszín: online, https://wigner-hu.zoom.us/j/87921507102?pwd=SjFidU5CT3cvVG1tSFplS0plNXB… Meeting ID: 879 2150 7102 Passcode: 973890
Összefoglaló:
The α-synuclein (αS) proteins' structural disorder was measured by ratios of heterogeneous water-binding interfaces. They showed the αS monomers, oligomers, and amyloids to possess secondary structural elements, although monomers are intrinsically disordered. Despite their disordered nature, monomers have 33% secondary structure, and therefore they are more compact than a random coil. At the lowest potential barriers with mobile hydration water, monomers are already functional, a monolayer of mobile hydration water is surrounding them. The solvent-accessible surface of the oligomers is ordered or homogenous in its interactions with water to 66%. In contrast, αS amyloids are disordered or heterogeneous to 75% of their solvent-accessible surface, and both wild type and A53T amyloids show identical, low-level hydration. Secondary structure predictions of proteins were compared to experimental results by wide-line ¹H NMR. αS variants were predicted to be disordered, as in the experiments, but the A53T mutant showed less predicted disorder, in contrast with the wide-line ¹H NMR result. The last third of the αS variant's sequence was a disordered binding site. β-Sheets are present in αSs, and they extend to more amino acid residues in the A53T mutant according to the predictions. The latter is verified by experiments. The comparison of the predictions with the experiments suggests that helical parts are buried.
