Controlling Drug Partitioning in Individual Protein Condensates through Laser-Induced Microscale Phase Transitions

Abstract

Gelation of protein condensates formed by liquid-liquid phase separation occurs in a wide range of biological contexts, from the assembly of biomaterials to the formation of fibrillar aggregates, and is therefore of interest for biomedical applications. Soluble-to-gel (sol-gel) transitions are controlled through macroscopic processes such as changes in temperature or buffer composition, resulting in bulk conversion of liquid droplets into microgels within minutes to hours. Using microscopy and mass spectrometry, we show that condensates of an engineered mini-spidroin (NT2repCT(YF)) undergo a spontaneous sol-gel transition resulting in the loss of exchange of proteins between the soluble and the condensed phase. This feature enables us to specifically trap a silk-domain-tagged target protein in the spidroin microgels. Surprisingly, laser pulses trigger near-instant gelation. By loading the condensates with fluorescent dyes or drugs, we can control the wavelength at which gelation is triggered. Fluorescence microscopy reveals that laser-induced gelation significantly further increases the partitioning of the fluorescent molecules into the condensates. In summary, our findings demonstrate direct control of phase transitions in individual condensates, opening new avenues for functional and structural characterization.

Published in

Journal of the American Chemical Society
2024, Volume: 146, number: 28, pages: 19555-19565 Publisher: AMER CHEMICAL SOC

SLU Authors

• Bohn Pessatti, Tomas

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Physical Chemistry


Publication identifier

DOI: https://doi.org/10.1021/jacs.4c06688

Permanent link to this page (URI)

https://res.slu.se/id/publ/131422