Reaction: choline + acceptor = betaine aldehyde + reduced acceptor
Glossary: betaine aldehyde = N,N,N-trimethyl-2-oxoethylammonium
choline = (2-hydroxyethyl)trimethylammonium
Other name(s): choline oxidase; choline-cytochrome c reductase; choline:(acceptor) oxidoreductase; choline:(acceptor) 1-oxidoreductase
Systematic name: choline:acceptor 1-oxidoreductase
Comments: A quinoprotein. In many bacteria, plants and animals, the osmoprotectant betaine is synthesized using different enzymes to catalyse the conversion of (1) choline into betaine aldehyde and (2) betaine aldehyde into betaine. In plants, the first reaction is catalysed by EC 220.127.116.11, choline monooxygenase, whereas in animals and many bacteria, it is catalysed by either membrane-bound choline dehydrogenase (EC 18.104.22.168) or soluble choline oxidase (EC 22.214.171.124) . The enzyme involved in the second step, EC 126.96.36.199, betaine-aldehyde dehydrogenase, appears to be the same in plants, animals and bacteria.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9028-67-5
1. Ameyama, M., Shinagawa, E., Matsuchita, K., Takimoto, K., Nakashima, K. and Adachi, O. Mammalian choline dehydrogenase is a quinoprotein. Agric. Biol. Chem. 49 (1985) 3623-3626.
2. Ebisuzaki, K. and Williams, J.N. Preparation and partial purification of soluble choline dehydrogenase from liver mitochondria. Biochem. J. 60 (1955) 644-646. [PMID: 13249959]
3. Gadda, G. and McAllister-Wilkins, E.E. Cloning, expression, and purification of choline dehydrogenase from the moderate halophile Halomonas elongata. Appl. Environ. Microbiol. 69 (2003) 2126-2132. [PMID: 12676692]
4. Waditee, R., Tanaka, Y., Aoki, K., Hibino, T., Jikuya, H., Takano, J., Takabe, T. and Takabe, T. Isolation and functional characterization of N-methyltransferases that catalyze betaine synthesis from glycine in a halotolerant photosynthetic organism Aphanothece halophytica. J. Biol. Chem. 278 (2003) 4932-4942. [PMID: 12466265]