Related Experiment Video
Updated: Nov 20, 2025
05:51
Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
6.5K
Quantum-Classical Path Integral Simulation of Excess Proton Dynamics in a Water Dimer Embedded in the Gramicidin
1Department of Chemistry, University of Illinois, 505 South Mathews Avenue, Urbana, Illinois 61801, United States.
Journal of Chemical Theory and Computation
|January 26, 2021
Summary
Proton transfer in a water dimer within the gramicidin A channel is accelerated by quantum tunneling and zero-point energy. This proton dynamics is primarily driven by oxygen pair oscillations.
Area of Science:
- Quantum chemistry
- Biophysics
- Molecular dynamics
Background:
- Proton transport is crucial in biological systems.
- Gramicidin A channels facilitate ion and proton movement across membranes.
- Understanding proton dynamics in confined environments is challenging.
Purpose of the Study:
- Investigate the relaxation dynamics of an excess proton in a water dimer.
- Elucidate the mechanisms driving proton transfer within the gramicidin A channel.
- Analyze the influence of quantum effects on proton transfer.
Main Methods:
- Quantum-classical path integral (QCPI) methodology.
- Transformation to internal coordinates for potential energy surface analysis.
- Simulations conducted at room temperature.
Main Results:
- Proton transfer is primarily driven by the oscillation of the oxygen pair.
- Transfer occurs mainly in single-well or low-barrier configurations.
- Quantum tunneling and zero-point energy significantly accelerate proton transfer dynamics.
Conclusions:
- Quantum effects play a vital role in accelerating proton transfer.
- Oxygen pair oscillations are key drivers of proton dynamics in this system.
- The gramicidin A channel environment influences proton transfer mechanisms.
More Related Videos
Related Concept Videos
01:25Aquaporins
5.8K
Aquaporins or AQPs are a family of integral membrane proteins whose primary function is to transport water, while some called aquaglyceroporins also transport glycerol. In addition, aquaporins have also been suspected to be involved in transporting volatile substances, such as carbon dioxide and ammonia, across membranes. Such AQPs that act as gas channels are often highly expressed in cells involved in the gaseous exchange, such as red blood cells, epithelial cells, and pulmonary capillaries.
5.8K
03:13Intermolecular Forces
66.4K
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen...
66.4K
01:24Protein Diffusion in the Membrane
5.2K
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
5.2K