TY - JOUR
T1 - Effect of Water Deuteration on Protein Electron Transfer
AU - Mostajabi Sarhangi, Setare
AU - Matyushov, Dmitry V.
N1 - Funding Information: This research was supported by the Army Research Office (ARO-W911NF2010320) and by the National Science Foundation (CHE-2154465). The supercomputer time was provided through Extreme Science and Engineering Discovery Environment (XSEDE) allocation MCB080071 and through ASU’s Research Computing. Inspiring discussions with Stuart Lindsay are gratefully acknowledged. Publisher Copyright: © 2023 American Chemical Society.
PY - 2023/1/26
Y1 - 2023/1/26
N2 - Traditional theories of long-range protein electron transfer describe the reaction rate in terms of the tunneling distance and the reaction free energy. They do not recognize two physical effects: (i) local wetting of the active site by hydration water and (ii) protein identity affecting the rate through dynamics and flexibility. We find, by molecular dynamics simulations, a significant, ∼25 times, slowing down of the rate of protein electron transfer upon deuteration. H/D substitution changes the rate constant pre-exponential factor in the regime of electron transfer controlled by medium dynamics. Switching from light to heavy water increases the effective medium relaxation time. The effect is caused by both a global change in the flexibility of the protein backbone and locally stronger hydrogen bonds to charged residues.
AB - Traditional theories of long-range protein electron transfer describe the reaction rate in terms of the tunneling distance and the reaction free energy. They do not recognize two physical effects: (i) local wetting of the active site by hydration water and (ii) protein identity affecting the rate through dynamics and flexibility. We find, by molecular dynamics simulations, a significant, ∼25 times, slowing down of the rate of protein electron transfer upon deuteration. H/D substitution changes the rate constant pre-exponential factor in the regime of electron transfer controlled by medium dynamics. Switching from light to heavy water increases the effective medium relaxation time. The effect is caused by both a global change in the flexibility of the protein backbone and locally stronger hydrogen bonds to charged residues.
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U2 - 10.1021/acs.jpclett.2c03690
DO - 10.1021/acs.jpclett.2c03690
M3 - Article
C2 - 36648391
SN - 1948-7185
VL - 14
SP - 723
EP - 729
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 3
ER -