Roberts, S. et al. Nat. Mater. https://doi.org/10.1038/s41563-018-0182-6 (2018).

There is growing interest in understanding the molecular and physical principles behind protein phase separation, because of its critical role in cellular functions. Roberts et al. explored the phase behaviors of intrinsically disordered polypeptides containing ordered protein domains. They recombinantly synthesized partial ordered polypeptides (POPs) that integrate disordered, thermoresponsive elastin-like polypeptides (ELPs) with ordered polyalanine helices. The integration of ordered domains alters the ELPs’ phase behavior, in which the newly synthesized POPs exhibit thermal hysteresis, the difference between transition temperatures defined during heating and cooling processes. This reversible thermal hysteresis is correlated with the amount of polymer helicity in POPs and can be tuned through changes in the ratio of ordered to disordered domains. The temperature-triggered phase separation drives POPs to form porous, physically cross-linked viscoelastic networks that hold potential for wound healing and tissue growth in vivo.