Effect of Peptide Sequence on the LCST-Like Transition of Elastin-Like Peptides and Elastin-Like Peptide–Collagen-Like Peptide Conjugates: Simulations and Experiments

• Published in: Biomacromolecules 2019-03, Vol.20 (3), p.1178-1189
• Main Authors: Prhashanna, Ammu, Taylor, Phillip A, Qin, Jingya, Kiick, Kristi L, Jayaraman, Arthi
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Collagen - chemistry; Elastin - chemistry; Hydrophobic and Hydrophilic Interactions; Molecular Dynamics Simulation; Peptides - chemistry; Phase Transition; Thermodynamics
• ISSN: 1525-7797; 1526-4602; 1526-4602
• DOI: 10.1021/acs.biomac.8b01503

Elastin-like polypeptides (ELPs) are thermoresponsive biopolymers that undergo an LCST-like phase transition in aqueous solutions. The temperature of this LCST-like transition, T t , can be tuned by varying the number of repeat units in the ELP, sequence and composition of the repeat units, the solution conditions, and via conjugation to other biomacromolecules. In this study, we show how and why the choice of guest (X) residue in the VPGXG pentad repeat tunes the T t of short ELPs, (VPGXG)4, in the free state and when conjugated to collagen-like peptides (CLPs). In experiments, the (VPGWG)4 chain (in short, WWWW) has a T t < 278 K, while (VPGFG)4 or FFFF has a T t > 353 K in both free ELP and ELP–CLP systems. The T t for the FWWF ELP sequence decreases from being >353 K for free ELP to