10.1021/acscatal.9b03345.s001
Philip Pagano
Philip
Pagano
Qi Guo
Qi
Guo
Chethya Ranasinghe
Chethya
Ranasinghe
Evan Schroeder
Evan
Schroeder
Kevin Robben
Kevin
Robben
Florian Häse
Florian
Häse
Hepeng Ye
Hepeng
Ye
Kyle Wickersham
Kyle
Wickersham
Alán Aspuru-Guzik
Alán
Aspuru-Guzik
Dan T. Major
Dan T.
Major
Lokesh Gakhar
Lokesh
Gakhar
Amnon Kohen
Amnon
Kohen
Christopher M. Cheatum
Christopher M.
Cheatum
Oscillatory Active-Site Motions Correlate with Kinetic
Isotope Effects in Formate Dehydrogenase
American Chemical Society
2019
FDH exhibits oscillatory frequency fluctuations
temperature dependence
transition state structure
Kinetic Isotope Effects
Formate
IR
mutations influence active-site dynamics
enzyme-catalyzed hydride transfers
Oscillatory Active-Site Motions Correlate
hydride transfer reaction
Candida boidinii exhibits
KIE
2019-11-11 05:29:43
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Oscillatory_Active-Site_Motions_Correlate_with_Kinetic_Isotope_Effects_in_Formate_Dehydrogenase/10282325
Thermal
motions of enzymes have been invoked to explain the temperature
dependence of kinetic isotope effects (KIEs) in enzyme-catalyzed hydride
transfers. Formate dehydrogenase (FDH) from Candida
boidinii exhibits a temperature-independent KIE that
becomes temperature-dependent upon mutation of hydrophobic residues
in the active site. Ternary complexes of FDH that mimic the transition
state structure allow investigation of how these mutations influence
active-site dynamics. A combination of X-ray crystallography, two-dimensional
infrared (2D IR) spectroscopy, and molecular dynamic simulations characterize
the structure and dynamics of the active site. FDH exhibits oscillatory
frequency fluctuations on the picosecond timescale, and the amplitude
of these fluctuations correlates with the temperature dependence of
the KIE. Both the kinetic and dynamic phenomena can be reproduced
computationally. These results provide experimental evidence for a
connection between the temperature dependence of KIEs and motions
of the active site in an enzyme-catalyzed reaction consistent with
activated tunneling models of the hydride transfer reaction.