A Central Disulfide Junction Drives Transient Network Formation in Elastin-Like Polypeptides, Enabling Low-Concentration Hydrogels
Abstract
The self-assembly of associative triblock copolymers composed of a central hydrophilic elastin-like polypeptide (ELP) block and short fatty acid end groups (C16) was investigated in aqueous solution. In one system, the ELP contains 80 pentapeptide units (C16-80-C16), whereas in the other two C16-ELP40 chains were oxidatively coupled through their terminal cysteine residues to form a central disulfide bond, yielding C16-(40)2-C16. Despite their nearly identical molecular weights and compositions, the two polymers exhibit markedly different self-assembly behaviors. C16-80-C16 forms large hydrophobic aggregates that remain kinetically trapped and do not develop a dynamically connected network. In contrast, C16-(40)2-C16 forms very small associative nodes with an aggregation number of only ∼3 chains. These nodes coexist with larger clusters and become dynamically interconnected at higher concentrations, leading to transparent hydrogels at concentrations as low as 2.5 wt %. Oscillatory rheology reveals a transient Maxwell network governed by a single relaxation process associated with the reversible association of the C16 end groups. SAXS, light scattering, cryo-TEM, and molecular modeling consistently support a model in which the central disulfide junction promotes transient network formation.
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BibTeX
@article{zhang2026central,
title = {{A Central Disulfide Junction Drives Transient Network Formation in Elastin-Like Polypeptides, Enabling Low-Concentration Hydrogels}},
author = {Tingting Zhang and Jean-François Le Meins and Jean-Paul Chapel and Saron Catak and Guillaume Goudounet and Olivier Sandre and Nadia Mahmoudi and Christophe Schatz and Bertrand Garbay},
journal = {ACS Macro Letters},
year = {2026},
month = aug,
doi = {10.1021/acsmacrolett.6c00338},
eprint = {2608.19810},
archivePrefix = {arXiv},
url = {https://u-bordeaux.hal.science/hal-05717870v2},
note = {CC BY-SA 4.0},
}
RIS
TY - JOUR
TI - A Central Disulfide Junction Drives Transient Network Formation in Elastin-Like Polypeptides, Enabling Low-Concentration Hydrogels
AU - Tingting Zhang
AU - Jean-François Le Meins
AU - Jean-Paul Chapel
AU - Saron Catak
AU - Guillaume Goudounet
AU - Olivier Sandre
AU - Nadia Mahmoudi
AU - Christophe Schatz
AU - Bertrand Garbay
PY - 2026
DA - 2026/08/12
JO - ACS Macro Letters
DO - 10.1021/acsmacrolett.6c00338
UR - https://u-bordeaux.hal.science/hal-05717870v2
AB - The self-assembly of associative triblock copolymers composed of a central hydrophilic elastin-like polypeptide (ELP) block and short fatty acid end groups (C16) was investigated in aqueous solution. In one system, the ELP contains 80 pentapeptide units (C16-80-C16), whereas in the other two C16-ELP40 chains were oxidatively coupled through their terminal cysteine residues to form a central disulfide bond, yielding C16-(40)2-C16. Despite their nearly identical molecular weights and compositions, the two polymers exhibit markedly different self-assembly behaviors. C16-80-C16 forms large hydrophobic aggregates that remain kinetically trapped and do not develop a dynamically connected network. In contrast, C16-(40)2-C16 forms very small associative nodes with an aggregation number of only ∼3 chains. These nodes coexist with larger clusters and become dynamically interconnected at higher concentrations, leading to transparent hydrogels at concentrations as low as 2.5 wt %. Oscillatory rheology reveals a transient Maxwell network governed by a single relaxation process associated with the reversible association of the C16 end groups. SAXS, light scattering, cryo-TEM, and molecular modeling consistently support a model in which the central disulfide junction promotes transient network formation.
SN - 2161-1653
ER -