Controllable coacervation of recombinantly produced spider silk protein using kosmotropic salts

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2020-02-15
Major/Subject
Mcode
Degree programme
Language
en
Pages
12
149-160
Series
Journal of Colloid and Interface Science, Volume 560
Abstract
Recent developments suggest that the phase transition of natural and synthetic biomacromolecules represents an important and ubiquitous mechanism underlying structural assemblies toward the fabrication of high-performance materials. Such a transition results in the formation of condensed liquid droplets, described as condensates or coacervates. Being able to effectively control the assembly of such entities is essential for tuning the quality and their functionality. Here we describe how self-coacervation of genetically engineered spidroin-inspired proteins can be preceded by a wide range of kosmotropic salts. We studied the kinetics and mechanisms of coacervation in different conditions, from direct observation of initial phase separation to the early stage of nucleation/growth and fusion into large fluid assemblies. We found that coacervation induced by kosmotropic salts follows the classical nucleation theory and critically relies on precursor clusters of few weak-interacting protein monomers. Depending onsolution conditions and the strength of the supramolecular interaction as a function of time, coacervates with a continuum of physiochemical properties were observed. We observed similar characteristics in other protein-based coacervates, which include having a spherical-ellipsoid shape in solution, an interconnected bicontinuous network, surface adhesion, and wetting properties. Finally, we demonstrated the use of salt-induced self-coacervates of spidroin-inspired protein as a cellulosic binder in dried condition.
Description
Keywords
Classical nucleation theory, Coacervate, Genetic engineering, Kosmotropic salt, Liquid-liquid phase transition, Protein engineering, Salting out, Silk-like protein
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Citation
Mohammadi , P , Christopher , J , Beaune , G , Engelhardt , P , Kamada , A , Timonen , J V I , Knowles , T P J , Penttila , M & Linder , M B 2020 , ' Controllable coacervation of recombinantly produced spider silk protein using kosmotropic salts ' , Journal of Colloid and Interface Science , vol. 560 , pp. 149-160 . https://doi.org/10.1016/j.jcis.2019.10.058