Quantitative comparison of protein dynamics in live cells and in vitro by in-cell 19F-NMRElectronic supplementary information (ESI) available. See DOI: 10.1039/c3cc39205h

Here we describe how a 19 F-probe incorporated into an endogenous protein by a chemical biology method revealed protein dynamics. By explicit determination of ligand-bound and unbound structures with X-ray crystallography, the quantitative comparison of the protein's dynamics in live cells and in vitro is presented. These results clearly demonstrated the greater conformational fluctuations of the intracellular protein, partially due to macromolecular crowding effects. The unprecedented quantitative comparison of the protein's dynamics in live cells and in vitro is presented.