Regensburg 2019 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 23: Biomaterials and biopolymers I (joint session BP/CPP)

BP 23.4: Vortrag

Donnerstag, 4. April 2019, 10:15–10:30, H10

Early Stage Self Assembly of Flexible Peptides — •Ali Asghar Hakami Zanjani and Joshua T. Berryman — University of Luxembourg, Luxembourg

We use accelerated simulation methods to investigate the early stage nucleation processes of a homologous series of hexapeptides: ILQINS (from hen's egg-white lysozyme), IFQINS (from human lysozyme) and TFQINS (a disease-related mutation in humans). We observe that the majority of initially formed one-dimensional single beta sheets in these systems have antiparallel alignment of peptide strands, in contrast to experimentally observed mature multi-sheet aggregates which have parallel strand alignment in all structures found to date [1-3].

We confirm the stability of the antiparallel aggregates by molecular dynamics simulations showing greater configurational stability for the antiparallel rather than parallel single beta sheets [4]. As mature antiparallel aggregates have not been observed for these systems we assume that such structures represent a kinetic trap, with limited potential to mature into amyloid fibrils or the related microcrystals. The existence of this kinetic trap offers the possibility to control amyloid formation by chemically directing small structures either towards or away from the antiparallel structures, depending if formation of macroscopic aggregates is considered beneficial or harmful.

[1] Reynolds et al., Nat. Comms. 8:1338 (2017)

[2] Lara et al., J. Am. Chem. Soc. 136(12):4732 (2014)

[3] Sievers, PhD Dissertations, (ProQuest, UMI: 3322087, 2008)

[4] Cooper, Beta-Sheet Geometry, (Birkbeck College, 1995)