Schmuck, Benjamin
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
Abstract
Spider silk formation involves tightly regulated protein assembly influenced by pH and the presence of ions. Kosmotropic salts induce phase separation of spidroins; however, their exact role in assembly is not clear. Here, we investigate how sodium and potassium phosphate affect spidroin interactions via the single-molecule method of mass photometry. We observed that spidroin oligomerization occurs at low nanomolar protein concentrations. Potassium ions were found to stabilize a compact conformation of individual spidroins and slow down pH-induced beta-sheet aggregation, consistent with its more kosmotropic nature. Microfluidic MP showed that pre-assembly of the protein through salt-induced phase separation reduced the number and size of oligomeric intermediates that form upon acidification. Together, the findings suggest that spidroins have an inherent ability to self-assemble, blurring the line between one- and two-phase status. Subtle differences in ion composition are sufficient to change spidroin stability and assembly, potentially contributing to silk spinning in vivo by balancing storage stability with rapid fiber formation.
Published in
Communications Materials
2026, volume: 7, number: 1, article number: 42
SLU Authors
Bohn Pessatti, Tomas
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
Rising, Anna
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
UKÄ Subject classification
Bio Materials
Publication identifier
- DOI: https://doi.org/https://doi.org/10.1038/s43246-025-01051-3
Permanent link to this page (URI)
https://res.slu.se/id/publ/145679