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Updated: Feb 12, 2026

FLIM-FRET Measurements of Protein-Protein Interactions in Live Bacteria.
Published on: August 25, 2020
FRET-based Stoichiometry Measurements of Protein Complexes in vitro
Francesca Mattiroli1, Yajie Gu1,2, Karolin Luger1
1Howard Hughes Medical Institute, University of Colorado Boulder, Department of Chemistry and Biochemistry, Boulder, CO, USA.
Abstract:
For a complete understanding of biochemical reactions, information on complex stoichiometry is essential. However, measuring stoichiometry is experimentally challenging. Our lab has developed a FRET-based assay to study protein complex stoichiometry in vitro. This assay, also known as Job plot, is set up as a continuous variation of the molar ratio between the two species, kept at constant total concentration. The FRET (Fluorescence Resonance Energy Transfer) between the two fluorescently-labeled proteins is measured and the stoichiometry is inferred from the sample with highest FRET signal. This approach allows us to assess complex stoichiometry in solution.
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