A1 Refereed original research article in a scientific journal
Liquid-Liquid Phase Separation and Assembly of Silk-like Proteins is Dependent on the Polymer Length
Authors: Lemetti, Laura; Scacchi, Alberto; Yin, Yin; Shen, Mengjie; Linder, Markus B.; Sammalkorpi, Maria; Aranko, A. Sesilja
Publisher: AMER CHEMICAL SOC
Publishing place: WASHINGTON
Publication year: 2022
Journal: Biomacromolecules
Journal name in source: BIOMACROMOLECULES
Journal acronym: BIOMACROMOLECULES
Volume: 23
Issue: 8
First page : 3142
Last page: 3153
Number of pages: 12
ISSN: 1525-7797
eISSN: 1526-4602
DOI: https://doi.org/10.1021/acs.biomac.2c00179
Abstract
Phase transitions have an essential role in the assembly of nature's protein-based materials into hierarchically organized structures, yet many of the underlying mechanisms and interactions remain to be resolved. A central question for designing proteins for materials is how the protein architecture and sequence affects the nature of the phase transitions and resulting assembly. In this work, we produced 82 kDa (1x), 143 kDa (2x), and 204 kDa (3x) silk-mimicking proteins by taking advantage of protein ligation by SpyCatcher/Tag protein-peptide pair. We show that the three silk proteins all undergo a phase transition from homogeneous solution to assembly formation. In the assembly phase, a length- and concentration-dependent transition between two distinct assembly morphologies, one forming aggregates and another coacervates, exists. The coacervates showed properties that were dependent on the protein size. Computational modeling of the proteins by a bead-spring model supports the experimental results and provides us a possible mechanistic origin for the assembly transitions based on architectures and interactions.
Phase transitions have an essential role in the assembly of nature's protein-based materials into hierarchically organized structures, yet many of the underlying mechanisms and interactions remain to be resolved. A central question for designing proteins for materials is how the protein architecture and sequence affects the nature of the phase transitions and resulting assembly. In this work, we produced 82 kDa (1x), 143 kDa (2x), and 204 kDa (3x) silk-mimicking proteins by taking advantage of protein ligation by SpyCatcher/Tag protein-peptide pair. We show that the three silk proteins all undergo a phase transition from homogeneous solution to assembly formation. In the assembly phase, a length- and concentration-dependent transition between two distinct assembly morphologies, one forming aggregates and another coacervates, exists. The coacervates showed properties that were dependent on the protein size. Computational modeling of the proteins by a bead-spring model supports the experimental results and provides us a possible mechanistic origin for the assembly transitions based on architectures and interactions.
UTU Research Portal