Encyclopedia of Biophysics

Living Edition
| Editors: Gordon Roberts, Anthony Watts, European Biophysical Societies

Quinone Cofactors

  • Victor L. Davidson
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-35943-9_46-1


A quinone is a cyclic organic compound that contains two carbonyl (C=O) groups that are in the same aromatic ring. Quinone cofactors associate with enzymes and participate in electron transfer or catalysis or both. Quinone cofactors may also be formed by posttranslational modification of amino acid residues of proteins.

Basic Characteristics

Membrane-Bound Quinones

Quinone molecules within cell membranes (Fig. 1) act as electron transfer shuttles between proteins that function in respiration and photosynthesis. During mitochondrial electron transport, ubiquinone (also called Coenzyme Q) accepts electrons from both Complex I and Complex II and donates electrons to Complex III. Ubiquinone is also present in bacterial electron transfer chains, although some anaerobic respiratory chains use menaquinone instead. During photosynthetic electron transfer, plastoquinone transfers electrons from the photosystem II reaction center to the cytochrome bf complex.
This is a preview of subscription content, log in to check access.


  1. Campillo-Brocal JC, Chacon-Verdue MD, Lucas-Elio P, Sanchez-Amat A (2015) Distribution in microbial genomes of genes similar to lodA and goxA which encode a novel family of quinoproteins with amino acid oxidase activity. BMC Genomics 16:231CrossRefPubMedPubMedCentralGoogle Scholar
  2. Davidson VL (2004) Electron transfer in quinoproteins. Arch Biochem Biophys 428:32–40CrossRefPubMedGoogle Scholar
  3. Davidson VL (2011) Generation of protein-derived redox cofactors by posttranslational modification. Mol BioSyst 7:29–37CrossRefPubMedGoogle Scholar
  4. Finney J, Moon H-J, Ronnebaum T, Lantz M, Mure M (2014) Human copper-dependent amino oxidases. Arch Biochem Biophys 546:19–32CrossRefPubMedPubMedCentralGoogle Scholar
  5. Floris G, Mondovi B (eds) (2009) Copper amine oxidases: structures, catalytic mechanisms, and roles in pathophysiology. CRC Press, Boca RatonGoogle Scholar
  6. Klinman JP, Bonnot F (2014) Intrigues and intracacies of the biosynthetic pathways for the enzymatic quinocofactors: PQQ, TTQ, CTC, TPQ and LTQ. Chem Rev 114:4343–4365CrossRefPubMedGoogle Scholar
  7. Matsushita K, Toyama H, Yamada M, Adachi O (2002) Quinoproteins: structure, function, and biotechnological applications. Appl Microbiol Biotechnol 58:13–22CrossRefPubMedGoogle Scholar
  8. Misra HS, Rajpurohit YS, Khairnar NP (2012) Pyrroloquinoline-quinone and its versatile roles in boplogical processes. J Biosci 37:313–325CrossRefPubMedGoogle Scholar
  9. Yukl ET, Liu F, Krzystekc J, Shin S, Jensen LMR, Davidson VL, Wilmot CM, Liu A (2013) A di-radical intermediate within the context of tryptophan tryptophylquinone biosynthesis. Proc Natl Acad Sci USA 110:4569–4573CrossRefPubMedGoogle Scholar

Copyright information

© European Biophysical Societies' Association (EBSA) 2018

Authors and Affiliations

  1. 1.Burnett School of Biomedical Sciences, College of MedicineUniversity of Central FloridaOrlandoUSA