Dresden 2017 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 19: Posters - Computational Biophysics
BP 19.2: Poster
Dienstag, 21. März 2017, 14:00–16:00, P1A
Structure formation of oligopeptides in the PRIME20 model — •Arne Böker and Wolfgang Paul — Institut für Physik, Martin-Luther-Universität Halle-Wittenberg
Much effort has recently been put into understanding amyloid formation in polypeptides. The amyloid state is a structure in which polypeptides aggregate as a stack of β-sheets, which is usually not the native state, leading to loss of function. Amyloids can cause a variety of diseases (amyloidoses) such as Huntington’s chorea, which is caused by an amyloidic state of expanded poly-Glutamine sequences.
The relation between conformations of a polypeptide is governed by local minima in the free energy function. Coarse-grained models tend to simplify the free energy in such a way that these local minima are ignored. To circumvent this problem, the level of coarse graining needs to be chosen appropriately. PRIME202 provides reasonable detail by mapping each amino acid to four beads, but keeps parameter space simple with the set of interactions reduced to 19 energy parameters.
We perform thermodynamic simulations of single PRIME20 chains using the "SAMC"3 variation of Wang-Landau Monte Carlo sampling which provides insight in different statistical ensembles at the expense of dynamic information. The aforementioned poly-Glutamines are compared to poly-Alanines with a lower tendency to form β structure motifs.
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