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Updated: Jul 4, 2026
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Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
Published on: January 16, 2016
Hydrogen tunneling in an enzyme active site: a quantum wavepacket dynamical perspective
Srinivasan S Iyengar1, Isaiah Sumner, Jacek Jakowski
1Department of Chemistry and Department of Physics, Indiana University, 800 E. Kirkwood Ave, Bloomington, Indiana 47405, USA. iyengar@indiana.edu
The Journal of Physical Chemistry. B
|June 6, 2008
Summary
Hydrogen tunneling in soybean lipoxygenase-1 is explored using quantum wavepacket dynamics. The study reveals a three-dimensional tunneling mechanism, accurately reproducing the kinetic isotope effect.
Area of Science:
- Biochemistry
- Quantum Chemistry
- Enzyme Catalysis
Background:
- Soybean lipoxygenase-1 is a key enzyme in biological pathways.
- Understanding hydrogen transfer mechanisms is crucial for enzyme function.
- Quantum effects like tunneling play a role in enzymatic reactions.
Purpose of the Study:
- To investigate the hydrogen tunneling mechanism in a model of soybean lipoxygenase-1.
- To compute the kinetic isotope effect and compare it with experimental values.
- To elucidate the three-dimensional nature of hydrogen and deuterium tunneling.
Main Methods:
- Quantum wavepacket dynamics simulations.
- Hybrid density functional theory for potential surfaces.
- Analysis of hydrogen nuclear orbitals (eigenstates) along the reaction coordinate.
Main Results:
- Accurate reproduction of the experimental kinetic isotope effect.
- Identification of tunneling through distorted s-type and p-type proton wave functions along the donor-acceptor axis.
- Observation of significant tunneling perpendicular to the donor-acceptor axis, highlighting a 3D process.
- Tunneling facilitated by curve and avoided crossings in proton eigenstate adiabats.
Conclusions:
- The study confirms a complex, three-dimensional hydrogen tunneling mechanism in soybean lipoxygenase-1.
- Quantum dynamics reveal contributions to tunneling both along and perpendicular to the donor-acceptor axis.
- Proton and deuterium transfer involve intricate wave function dynamics and interactions.
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