Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Deactivation Processes: Jablonski Diagram01:25

Deactivation Processes: Jablonski Diagram

Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
The Electron Transport Chain01:30

The Electron Transport Chain

The electron transport chain or oxidative phosphorylation is an exothermic process in which free energy released during electron transfer reactions is coupled to ATP synthesis. This process is a significant source of energy in aerobic cells, and therefore inhibitors of the electron transport chain can be detrimental to the cell's metabolic processes.
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q in...
Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Radical Reactivity: Intramolecular vs Intermolecular01:33

Radical Reactivity: Intramolecular vs Intermolecular

Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak carbon–halogen...
Electron Transport Chains01:28

Electron Transport Chains

The final stage of cellular respiration is oxidative phosphorylation that consists of two steps: the electron transport chain and chemiosmosis. The electron transport chain is a set of proteins found in the inner mitochondrial membrane in eukaryotic cells. Its primary function is to establish a proton gradient that can be used during chemiosmosis to produce ATP and generate electron carriers, such as NAD+ and FAD, that are used in glycolysis and the citric acid cycle.
The ETC is comprised of...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Thermodynamic Modeling of Glass Formation and DFT Calculations of Li<sub>2</sub>O-K<sub>2</sub>O-SiO<sub>2</sub> Melt Crystallization Within a Unified Structural Model.

Inorganic chemistry·2026
Same author

Nanobodies as therapies for loss-of-function misfolding diseases: the example of Primary Hyperoxaluria Type 1.

International journal of biological macromolecules·2026
Same author

Hard-Wired Solid-State Bioelectronic Micropore Devices: Permanent Metal-Protein-Metal Junction Proof-of-Concept.

Small (Weinheim an der Bergstrasse, Germany)·2025
Same author

Without Contact Resistance, Proteins in Thin-Film Solid-State Junctions Can Be Efficient Electronic Conducting Materials.

Advanced materials (Deerfield Beach, Fla.)·2025
Same author

Protein Electronic Energy Transport Levels Derived from High-Sensitivity Near-UV and Constant Final State Yield Photoemission Spectroscopy.

Small methods·2024
Same author

Phosphorylation of cytosolic hPGK1 affects protein stability and ligand binding: implications for its subcellular targeting in cancer.

The FEBS journal·2024

Related Experiment Video

Updated: May 30, 2026

Characterizing Mediated Extracellular Electron Transfer in Lactic Acid Bacteria with a Three-Electrode, Two-Chamber Bioelectrochemical System
10:23

Characterizing Mediated Extracellular Electron Transfer in Lactic Acid Bacteria with a Three-Electrode, Two-Chamber Bioelectrochemical System

Published on: August 23, 2024

Intramolecular electron transfer in laccases.

Ole Farver1, Scot Wherland, Olga Koroleva

  • 1Institute of Analytical Chemistry, University of Copenhagen, Copenhagen, Denmark. of@farma.ku.dk

The FEBS Journal
|July 28, 2011
PubMed
Summary

Electron transfer rates and activation parameters were measured for laccase enzymes from fungus and tree. Differences in electron transfer mechanisms were observed between Trametes hirsuta laccase and Rhus vernicifera laccase.

More Related Videos

Synthesis of Plant Phenol-derived Polymeric Dyes for Direct or Mordant-based Hair Dyeing
09:46

Synthesis of Plant Phenol-derived Polymeric Dyes for Direct or Mordant-based Hair Dyeing

Published on: December 1, 2016

Measuring Interactions between Fluorescent Probes and Lignin in Plant Sections by sFLIM Based on Native Autofluorescence
07:15

Measuring Interactions between Fluorescent Probes and Lignin in Plant Sections by sFLIM Based on Native Autofluorescence

Published on: January 2, 2020

Related Experiment Videos

Last Updated: May 30, 2026

Characterizing Mediated Extracellular Electron Transfer in Lactic Acid Bacteria with a Three-Electrode, Two-Chamber Bioelectrochemical System
10:23

Characterizing Mediated Extracellular Electron Transfer in Lactic Acid Bacteria with a Three-Electrode, Two-Chamber Bioelectrochemical System

Published on: August 23, 2024

Synthesis of Plant Phenol-derived Polymeric Dyes for Direct or Mordant-based Hair Dyeing
09:46

Synthesis of Plant Phenol-derived Polymeric Dyes for Direct or Mordant-based Hair Dyeing

Published on: December 1, 2016

Measuring Interactions between Fluorescent Probes and Lignin in Plant Sections by sFLIM Based on Native Autofluorescence
07:15

Measuring Interactions between Fluorescent Probes and Lignin in Plant Sections by sFLIM Based on Native Autofluorescence

Published on: January 2, 2020

Area of Science:

  • Biochemistry
  • Biophysical Chemistry
  • Enzymology

Background:

  • Laccases are multicopper oxidases catalyzing oxidation of phenolic compounds.
  • Internal electron transfer between copper centers (T1 to T3) is crucial for laccase activity.
  • Understanding these electron transfer dynamics is key to enzyme function.

Purpose of the Study:

  • To determine rate constants and activation parameters for T1 to T3 copper electron transfer in fungal (Trametes hirsuta) and tree (Rhus vernicifera) laccases.
  • To elucidate the mechanisms of initial T1 site reduction in these enzymes.
  • To compare electron transfer properties with other multicopper oxidases.

Main Methods:

  • Pulse radiolysis was employed to study electron transfer kinetics.
  • Kinetic data were analyzed to determine rate constants and activation parameters (enthalpy and entropy).
  • Electron transfer theory and structural information were used for comparative analysis.

Main Results:

  • Rate constants at 298 K were 25 ± 1 s⁻¹ for T. hirsuta laccase and 1.1 ± 0.1 s⁻¹ for R. vernicifera laccase.
  • Activation enthalpies were 39.7 ± 5.0 kJ·mol⁻¹ (T. hirsuta) and 9.8 ± 0.2 kJ·mol⁻¹ (R. vernicifera).
  • T. hirsuta laccase showed direct T1 reduction, while R. vernicifera laccase exhibited indirect reduction via a disulfide radical.

Conclusions:

  • Significant differences exist in electron transfer kinetics and mechanisms between fungal and tree laccases.
  • The study provides insights into the structure-function relationships governing electron transfer in multicopper oxidases.
  • Comparative analysis highlights the diversity of electron transfer pathways in laccases.