TY - JOUR
T1 - Why are Vibrational Lines Narrow in Proteins?
AU - Martin, Daniel R.
AU - Matyushov, Dmitry V.
N1 - Funding Information:
This research was supported by the National Science Foundation (CHE-1800243). CPU time was provided by the National Science Foundation through XSEDE resources (TG-MCB080071).
Publisher Copyright:
Copyright © 2020 American Chemical Society.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/8/6
Y1 - 2020/8/6
N2 - The vibrational Stark effect in proteins yields line shifts indicative of strong internal electric fields up to a few volts per angstrom. These values are supported by numerical simulations of proteins. The simulations also show a significant breadth of field fluctuations translating to inhomogeneous broadening of vibrational lines. According to fluctuation-dissipation arguments, strong internal fields should lead to broad lines. Experimentally reported vibrational lines in proteins are, however, very narrow. This disconnect is explained here in terms of the insufficient (nonergodic) sampling of the protein's configurations on the lifetime of the vibrational probe. The slow component of the electric field fluctuations in proteins relaxes on the time scale of tens of nanoseconds and is dynamically frozen on the vibrational lifetime.
AB - The vibrational Stark effect in proteins yields line shifts indicative of strong internal electric fields up to a few volts per angstrom. These values are supported by numerical simulations of proteins. The simulations also show a significant breadth of field fluctuations translating to inhomogeneous broadening of vibrational lines. According to fluctuation-dissipation arguments, strong internal fields should lead to broad lines. Experimentally reported vibrational lines in proteins are, however, very narrow. This disconnect is explained here in terms of the insufficient (nonergodic) sampling of the protein's configurations on the lifetime of the vibrational probe. The slow component of the electric field fluctuations in proteins relaxes on the time scale of tens of nanoseconds and is dynamically frozen on the vibrational lifetime.
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U2 - 10.1021/acs.jpclett.0c01760
DO - 10.1021/acs.jpclett.0c01760
M3 - Article
C2 - 32634314
AN - SCOPUS:85089607128
SN - 1948-7185
VL - 11
SP - 5932
EP - 5937
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 15
ER -