Related Experiment Video
Updated: Aug 23, 2026

EPR Monitored Redox Titration of the Cofactors of Saccharomyces cerevisiae Nar1
Published on: November 26, 2014
Triiodide reduction by cellobiose:quinone oxidoreductase of Phanerochaete chrysosporium
1Department of Chemical and Biological Sciences, Oregon Graduate Institute of Science and Technology, Beaverton, OR 97006-1999.
Abstract:
Cellobiose:quinone oxidoreductase (CBQase) in the presence of cellobiose inhibits peroxidase-catalyzed oxidation of iodide to triiodide (I3). This inhibition is due to the two-electron reduction of I3- by CBQase. The apparent Km of I3- for this reaction is 120 microM and the specific activity is 57 mumol.min-1.mg-1. A proposed mechanism for I3- reduction by CBQase involves initial reduction of the flavin moiety by cellobiose to produce a dihydroflavin. This is followed by the substitution of one of the iodine atoms of I3- at the C(4a)-position of dihydroflavin to generate C(4a)-iododihydroflavin and two iodide ions. The C(4a)-iododihydroflavin eliminates HI to regenerate the oxidized CBQase.
Related Concept Videos
The Z-Scheme of Electron Transport in Photosynthesis
Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Electron Transport Chain: Complex III and IV
Phase I Reactions: Reductive Reactions

