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 Experiment Videos

Characterization of topa quinone cofactor

K Kano1, T Mori, B Uno

  • 1Gifu Pharmaceutical University, Japan.

Biochimica Et Biophysica Acta
|July 11, 1993
PubMed
Summary

Electrochemical studies reveal topa quinone, an amine oxidase cofactor, undergoes reversible redox reactions. Its structure and limited redox catalysis are linked to its quinone type.

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Effects of preemptive analgesia with intravenous acetaminophen on postoperative pain relief in patients undergoing third molar surgery: a prospective, single-blind, randomized controlled trial.

Medicina oral, patologia oral y cirugia bucal·2020
Same author

TTF-1/NKX2-1 binds to DDB1 and confers replication stress resistance to lung adenocarcinomas.

Oncogene·2017
Same author

Proposal of a new mechanism for the directional propagation of the action potential using a mimicking system.

Physical chemistry chemical physics : PCCP·2017
Same author

Regulation of the lysophosphatidylserine and sphingosine 1-phosphate levels in autologous whole blood by the pre-storage leukocyte reduction.

Transfusion medicine (Oxford, England)·2016
Same author

Diagnosis and therapy with labeled antibodies.

Immunology today·2014
Same author

Lung cancer associated with an azygos lobe successfully treated with video-assisted thoracoscopic surgery.

Asian journal of endoscopic surgery·2012

Area of Science:

  • Bioinorganic Chemistry
  • Electrochemistry
  • Spectroscopy

Background:

  • Topa quinone (6-hydroxydopa quinone) is the organic cofactor in copper-containing amine oxidases.
  • Understanding its electrochemical properties is crucial for elucidating enzyme mechanisms.

Purpose of the Study:

  • To electrochemically characterize topa quinone and its redox states.
  • To determine the acid-dissociation constants and redox potentials.
  • To investigate the structural basis for its redox catalytic activity.

Main Methods:

  • Cyclic voltammetry at a mercury electrode.
  • Digital simulation of electrochemical waves.
  • Spectroscopic analysis (UV-Vis, ESR).
  • Ab initio energy minimization calculations.

Main Results:

  • Topa quinone exhibits a reversible two-step, one-electron redox conversion via a semiquinone intermediate.
  • Electrochemical titration determined acid-dissociation constants and redox potentials.
  • At pH 7.0, topa quinone is deprotonated with a two-electron redox potential of 0.079 V vs. NHE.
  • No redox catalytic activity was observed for amine or NADH oxidation.

Conclusions:

  • The electrochemical behavior of topa quinone is well-defined, involving reversible redox transitions.
  • Energy minimization suggests an intermediate electronic structure, influencing its catalytic function.
  • The limited redox catalysis is attributed to the partial p-quinone character of the deprotonated anion.

Related Experiment Videos