Related Experiment Video
Updated: Nov 21, 2025

Inner Mitochondrial Membrane Sensitivity to Na+ Reveals Partially Segmented Functional CoQ Pools
Published on: July 20, 2022
A cytochrome c is the natural electron acceptor for nicotine oxidoreductase
Mark Dulchavsky1,2, Christopher T Clark3, James C A Bardwell4,5
1Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA.
Abstract:
Nicotine oxidoreductase (NicA2), a member of the flavin-containing amine oxidase family, is of medical relevance as it shows potential as a therapeutic to aid cessation of smoking due to its ability to oxidize nicotine into a non-psychoactive metabolite. However, the use of NicA2 in this capacity is stymied by its dismal O2-dependent activity. Unlike other enzymes in the amine oxidase family, NicA2 reacts very slowly with O2, severely limiting its nicotine-degrading activity. Instead of using O2 as an oxidant, we discovered that NicA2 donates electrons to a cytochrome c, which means that NicA2 is actually a dehydrogenase. This is surprising, as enzymes of the flavin-containing amine oxidase family were invariably thought to use O2 as an electron acceptor. Our findings establish new perspectives for engineering this potentially useful therapeutic and prompt a reconsideration of the term 'oxidase' in referring to members of the flavin-containing amine 'oxidase' family.
Related Concept Videos
Role of Reduced Coenzymes NADH and FADH₂
Oxidation and Reduction of Organic Molecules
The removal of an electron from a molecule, results in a...
Electron Carriers
Over the many stages of cellular respiration, glucose breaks down into carbon dioxide and water. Electron carriers pick up electrons lost by glucose in these reactions, temporarily storing and releasing them into the electron...
Redox Reactions
Redox Reactions
Electron Transport Chain: Complex III and IV

