The liquid structure of elastin

• Published in: eLife Vol. 6
• Main Authors: Rauscher, Sarah, Pomès, Régis
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 09.11.2017; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: Alcohol; Elastin; Elastin - chemistry; Elastin - metabolism; Entropy; Hydrogen; Hydrogen bonds; Hydrophobicity; intrinsically-disordered protein; Molecular dynamics; Molecular Dynamics Simulation; Packaging; Peptides; phase separation; protein aggregation; Protein Conformation; Protein Multimerization; Protein structure; Proteins; self-assembled elastomer; Self-assembly; Skin; Structural Biology and Molecular Biophysics; Structure (Literature); Structure-function relationships; Uterus; Canada; phase separation; protein aggregation; structural biology; none; molecular dynamics; biophysics; self-assembled elastomer; intrinsically-disordered protein
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.26526

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.