@article {545, title = {Functional-State Dependence of Picosecond Protein Dynamics}, journal = {J. Phys. Chem. B}, volume = {125}, year = {2021}, pages = {11134-11140}, chapter = {11134}, abstract = {

We examine temperature-dependent picosecond dynamics of two benchmarking proteins lysozyme and cytochrome c using temperature-dependent terahertz permittivity measurements. We find that a double Arrhenius temperature dependence with activation energies E1 \~{} 0.1 kJ/mol and E2 \~{} 10 kJ/mol fits the folded and ligand-free state response. The higher activation energy is consistent with the so-called protein dynamical transition associated with beta relaxations at the solvent{\textendash}protein interface. The lower activation energy is consistent with correlated structural motions. When the structure is removed by denaturing, the lower-activation-energy process is no longer present. Additionally, the lower-activation-energy process is diminished with ligand binding but not for changes in the internal oxidation state. We suggest that the lower-energy activation process is associated with collective structural motions that are no longer accessible with denaturing or binding.

}, doi = {10.1021/acs.jpcb.1c05018}, author = {George, D. K. and Chen, J. Y. and He, Yunfen and Knab, J. R. and Markelz, A. G.} }