Sequence Length Controls Coil-to-Globule Transition in Elastin-like Polypeptides

It appeared certain that elastin condensates retain liquid-like properties. However, a recent experimental study demonstrated that their aggregate states might depend on the length of hydrophobic domains. To gain microscopic insight into this behavior, we employ atomistic modeling to assess the conformational properties of hydrophobic elastin-like polypeptides (ELPs). We find that short ELPs always remain in coil-like conformations, while the longer ones prefer globule states. While the former engages in intrapeptide hydrogen bonds temporarily, retaining their liquid-like properties, the latter forms hundreds of nanosecond-long intrapeptide hydrogen bonds attributed to ordered secondary structure motifs. Our work demonstrates that the sequence length modulates the material properties of elastin condensates.