Related Experiment Video
Updated: Jul 16, 2026
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
10:01
Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
Water-mediated electron transfer between protein redox centers.
Agostino Migliore1, Stefano Corni, Rosa Di Felice
1National Center on nanoStructures and bioSystems at Surfaces (S3) of INFM-CNR, Modena, Italy. smigliore@unimore.it
The Journal of Physical Chemistry. B
|March 29, 2007
Summary
Water molecules significantly impact electron transfer (ET) rates in proteins like azurin. Favorable water arrangements can enhance ET kinetics by balancing electrostatic effects and mediating coupling pathways.
Area of Science:
- Biophysical Chemistry
- Computational Biochemistry
- Electron Transfer Theory
Background:
- Water molecules near redox centers influence electron transfer (ET) properties.
- Understanding these effects is crucial for predicting and controlling biological ET.
Purpose of the Study:
- Investigate the impact of intervening water molecules on azurin's electron self-exchange reaction.
- Analyze how water conformation and electrostatic interactions affect ET kinetics.
Main Methods:
- Performed conformational sampling of the water medium.
- Utilized a novel ab initio method to compute transfer integrals.
- Calculated electronic couplings and compared with Empirical Pathways (EP) method.
Main Results:
- Interfacial water molecules slightly increase the overall ET rate in azurin dimers.
- Specific water conformations can significantly enhance ET kinetics.
- Found an interplay between electrostatic interactions and water's mediation of ET coupling.
Conclusions:
- Water-mediated electron tunneling is not solely dependent on pathway geometry.
- Electrostatic effects of water conformation are critical for ET kinetics.
- The study provides a physical basis for discrepancies between ab initio and EP methods.
Related Concept Videos
01:27Redox Reactions
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
01:24Redox Reactions
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
01:29Electron Transport Chain Components
The electron transport chain (ETC) is a crucial metabolic pathway that facilitates energy conversion in prokaryotic and eukaryotic cells. In eukaryotes, the ETC comprises four membrane-associated protein complexes in the inner mitochondrial membrane. In prokaryotes, the ETC in the plasma membrane can vary in composition, with fewer or different complexes depending on the organism and environmental conditions. These complexes transfer electrons from electron donors, such as NADH and FADH2, to...
01:43Electron Transport Chain: Complex III and IV
During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
01:19Oxidation and Reduction of Organic Molecules
Energy production within a cell involves many coordinated chemical pathways. Most of these pathways are combinations of oxidation and reduction reactions, which occur at the same time. An oxidation reaction strips an electron from an atom in a compound, and the addition of this electron to another compound is a reduction reaction. Because oxidation and reduction usually occur together, these pairs of reactions are called redox reactions.
The removal of an electron from a molecule, results in a...
The removal of an electron from a molecule, results in a...
01:29The Photochemical Reaction Center
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...