Conformational Ensembles from Experimental Data and Computer Simulations

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Conformational Ensembles from Experimental Data
and Computer Simulations Poster Abstracts
115
80-POS Board 40
Conformational Ensembles of Phase-Separating Elastin-Like Peptides from NMR and
Molecular Simulations
Quang Huynh1,2, Sean Reichheld1, Sarah Rauscher2,3, Simon Sharpe1,2, Régis Pomès1,2.
1Hospital for Sick Children, Toronto, ON, Canada, 2University of Toronto, Toronto, ON,
Canada, 3Max Planck Institute, Goettingen, Germany.
Elastin endows skin, arteries, the lung, and the uterus with extensibility and elasticity. Elastin
and elastin-like peptides are structurally disordered and self-aggregate via liquid phase
separation. Despite extensive study, the structural basis for the self-assembly and the mechanical
properties of elastin remains unclear. As an essential step towards elucidating the structural
ensemble of elastin, we combine molecular dynamics simulations and NMR spectroscopy to
study an elastin-like peptide modelled after the sequence of alternating hydrophobic and cross-
linking domains of elastin. Computational and spectroscopic results are in excellent agreement.
Although the peptide is highly disordered, it possesses a significant propensity for local
secondary structure. The cross-linking domains are characterized by fluctuating α-helical
structure, whereas the hydrophobic domains form sparse and transient hydrogen-bonded β-turns.
As a result, the individual domains are collapsed but not compact, and they remain disordered
and hydrated despite their predominantly hydrophobic character. These findings resolve long-
standing controversies regarding the structure and function of elastin and afford insight into the
physical and structural basis for the phase separation of disordered proteins.