Abstract
A high-throughput microrheological assay is employed to assess the gelation kinetics of a coiled-coil protein, Q, across a compositional space with varying ionic strengths and pH values. Two methods of passive microrheology─multiple particle tracking (MPT) and differential dynamic microscopy (DDM)─are used to determine mean-squared displacements of tracer beads embedded in protein solutions with respect to lag time over a fixed period. MPT data was analyzed to determine gelation kinetics in a high-throughput, automatable manner by fitting relaxation exponents to sigmoidal curves and verifying with the more traditionally used time-cure superposition. DDM-determined gelation time was assessed as the last resolvable time, which we found to be on a similar scale to gelation times given by MPT. Both methods show distinct advantages with regard to being used in a high-throughput, automatable setup; DDM can serve as an effective initial screen for rapid gelation kinetics due to it requiring less user intervention and inputs, with MPT giving a more complete understanding of the entire gelation process. Using these methods, a clear optimum for rapid gelation was observed near the isoelectric point of Q and at higher ionic strengths over the compositional space studied.
Original language | English (US) |
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Pages (from-to) | 1239-1247 |
Number of pages | 9 |
Journal | Macromolecules |
Volume | 55 |
Issue number | 4 |
DOIs | |
State | Published - Feb 22 2022 |
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry