@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.} } @article {184, title = {Photoactive yellow protein terahertz response: hydration, heating and intermediate states}, journal = {IEEE Transactions on Terahertz Science and Technology}, volume = {3}, number = {3}, year = {2013}, pages = {288-294}, isbn = {2156-342X}, doi = {https://doi.org/10.1109/TTHZ.2013.2256233}, author = {George, Deepu K and Knab, Joseph R and He, Yunfen and Kumauchi, Masato and Birge, Robert R and Hoff, Wouter D and Markelz, Andrea G} } @article {187, title = {Evidence of protein collective motions on the picosecond timescale}, journal = {Biophysical Journal}, volume = {100}, number = {4}, year = {2011}, pages = {1058-1065}, isbn = {0006-3495}, doi = {https://dx.doi.org/10.1016\%2Fj.bpj.2010.12.3731}, author = {He, Yunfen and Chen, J-Y and Knab, Joseph R and Zheng, Wenjun and Markelz, Andrea G} } @proceedings {188, title = {The role of structure in the protein dynamical transition}, year = {2008}, pages = {1-3}, publisher = {IEEE}, isbn = {1424421195}, doi = {https://doi.org/10.1109/ICIMW.2008.4665800}, author = {He, Yunfen and Markelz, Andrea G} } @article {293, title = {Protein dynamical transition in terahertz dielectric response}, journal = {Chemical Physics Letters}, volume = {442}, year = {2007}, pages = {413 - 417}, abstract = {

The 200K protein dynamical transition is observed for the first time in the terahertz dielectric response. The complex dielectric permittivity ε=ε'+iε" is determined in the 0.2{\textendash}2.0THz and 80{\textendash}294K ranges. ε" has a linear temperature dependence up to 200K then sharply increases. The low temperature linear dependence in ε" suggests anharmonicity for temperatures 80K\<t\<180k, challenging="" the="" assumed="" harmonicity="" below="" 200k.="" temperature="" dependence="" is="" consistent="" with="" thermally="" activated="" sidechain="" motions="" and="" shows="" involved="" in="" dynamical="" transition="" extend="" to="" subpicosecond="" time="" scales.\<="" div=""\>

}, isbn = {0009-2614}, doi = {10.1016/j.cplett.2007.05.080}, url = {https://www.sciencedirect.com/science/article/pii/S000926140700680X}, author = {Markelz, Andrea G. and Knab, Joseph R. and Chen, Jing Yin and He, Yunfen} } @article {191, title = {Terahertz measurements of protein relaxational dynamics}, journal = {Proceedings of the IEEE}, volume = {95}, number = {8}, year = {2007}, pages = {1605-1610}, isbn = {0018-9219}, doi = {10.1109/JPROC.2007.898906}, author = {Knab, Joseph R and Chen, Jing-Yin and He, Yunfen and Markelz, Andrea G} } @proceedings {192, title = {Protein conformational dynamics measured with terahertz time domain spectroscopy}, year = {2006}, pages = {183-183}, publisher = {IEEE}, isbn = {1424403995}, doi = {https://doi.org/10.1088/0031-9155/47/21/318}, author = {Knab, Joseph R and Chen, Jing-Yin and Ye, Shuji and He, Yunfen and Markelz, Andrea G} }