Equipe : Thématiques

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Protein interactions with FCS and FRET

Single molecule fluctuation dynamics reveal protein size, structure and affinities

Principal investigator : Jerome Wenger

Fluorescence Correlation Spectroscopy uses a confocal microscope to collect the light from luminescent molecules moving across a femtoliter observation volume (one femtoliter volume is one micron cube). The fluctuating number of fluorophores in this observation volume gives rise to intensity fluctuations which provide information about diffusion, molecular concentration and associations. FRET uses donor-acceptor fluorescence energy transfer as nanoscopic ruler to monitor conformation changes and association dynamics.

We apply FCS and FRET to monitor the interaction dynamics of various proteins, including :

  • CP12, a nuclear-encoded chloroplast protein, and the two enzymes glyceraldehyde-3-phosphate dehydrogenase GAPDH and phosphoribulokinase PRK
  • MreB, a homologue to actin in prokaryotes and its refolding with the chaperonins GroEL/GroES and TRiC.
  • Transient receptor potential ankyrin 1 (TRPA1) interacting with calcium and calmodulin
  • Ferredoxin and DPS DNA binding protein
  • Annexin as calcium probe


[4] S. B. Moparthi, U. Carlsson, R. Vincentelli, B.-H. Jonsson, P. Hammarström, J. Wenger, Differential conformational modulations of MreB folding upon interactions with GroEL/ES and TRiC chaperonin components, Sci. Rep. 6, 28386 (2016).
[3] S.B. Moparthi, G. Thieulin-Pardo, J. de Torres, P. Ghenuche, B. Gontero, J. Wenger, FRET analysis of CP12 structural interplay by GAPDH and PRK, Biochem. Biophys. Res. Comm. 458, 488-493 (2015).
[2] S.B. Moparthi, G. Thieulin-Pardo, P. Mansuelle, H. Rigneault, B. Gontero, J. Wenger, Conformational modulation and hydrodynamic radii of CP12 protein and its complexes probed by fluorescence correlation spectroscopy, FEBS Journal 281, 3206-3217 (2014)
[1] C. Favard, J. Wenger, P.-F. Lenne, H. Rigneault, FCS diffusion laws on two-phases lipid membranes : experimental and Monte-carlo simulations determination of domain mean size, Biophys. J. 100, 1242-1251 (2011).