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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 2: Modeling and Simulation of Soft Matter I

CPP 2.8: Talk

Monday, March 18, 2024, 11:45–12:00, H 0107

Statistical Analysis of the Dimerization of Amyloid-β(1-40) and Amyloid-β(1-42) — •Christian Lauer and Wolfgang Paul — Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany

We present a numerical investigation of the dimerization of the Amyloid-β(1-40) and Amyloid-β(1-42) peptides. The study employs the PRIME20 intermediate resolution protein model and a flat-histogram type Monte Carlo simulation approach that gives access to the thermodynamic equilibrium of the system over the complete control parameter range, which here is the temperature. Thermodynamic analysis reveals that for densities comparable to typical in-vitro experimental conditions, the folding and aggregation transitions of the systems occure simultaneously. However, looking at the difference of intra- and inter-molecular energy contributions, an increased aggregation propensity of Amyloid-β(1-42) compared to Amyloid-β(1-40) is revealed. Hydrogen-bond probability maps show segments at the N-terminus of the peptide with intra-chain anti-parallel alignment, corresponding to intra-chain beta-sheet structures, while the C-terminus shows a more diverse cast of possible configurations. We use Ramachandran plots to further investigate the influence of the different chain segments on the structure formation of Amyloid-β.

Keywords: Stochastic Approximation Monte Carlo (SAMC); amyloid formation; Amyloid-beta