The liquid structure of elastin
Abstract
The protein elastin imparts extensibility, elastic recoil, and resilience to tissues including arterial walls, skin, lung alveoli, and the uterus. Elastin and elastin-like peptides are hydrophobic, disordered, and undergo liquid-liquid phase separation upon self-assembly. Despite extensive study, the structure of elastin remains controversial. We use molecular dynamics simulations on a massive scale to elucidate the structural ensemble of aggregated elastin-like peptides. Consistent with the entropic nature of elastic recoil, the aggregated state is stabilized by the hydrophobic effect. However, self-assembly does not entail formation of a hydrophobic core. The polypeptide backbone forms transient, sparse hydrogen-bonded turns and remains significantly hydrated even as self-assembly triples the extent of non-polar side-chain contacts. Individual chains in the assembly approach a maximally-disordered, melt-like state which may be called the liquid state of proteins. These findings resolve long-standing controversies regarding elastin structure and function and afford insight into the phase separation of disordered proteins.
Data availability
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Microsecond-long molecular dynamics trajectory of an aggregate of elastin-like peptides in waterAvailable at Figshare under a CC BY 4.0 License.
Article and author information
Author details
Funding
Canadian Institutes of Health Research (MOP84496)
- Régis Pomès
Natural Sciences and Engineering Research Council of Canada
- Sarah Rauscher
Hospital for Sick Children
- Sarah Rauscher
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Gerhard Hummer, Max Planck Institute of Biophysics, Germany
Version history
- Received: March 6, 2017
- Accepted: October 11, 2017
- Accepted Manuscript published: November 9, 2017 (version 1)
- Version of Record published: November 27, 2017 (version 2)
Copyright
© 2017, Rauscher & Pomès
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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