Reaction: betaine aldehyde + NAD+ + H2O = betaine + NADH + 2 H+
Glossary: betaine = glycine betaine = N,N,N-trimethylglycine = N,N,N-trimethylammonioacetate
betaine aldehyde = N,N,N-trimethyl-2-oxoethylammonium
Other name(s): betaine aldehyde oxidase; BADH; betaine aldehyde dehydrogenase; BetB
Systematic name: betaine-aldehyde:NAD+ oxidoreductase
Comments: In many bacteria, plants and animals, the osmoprotectant betaine is synthesized in two steps: (1) choline to betaine aldehyde and (2) betaine aldehyde to betaine. This enzyme is involved in the second step and appears to be the same in plants, animals and bacteria. In contrast, different enzymes are involved in the first reaction. In plants, this reaction is catalysed by EC 1.14.15.7 (choline monooxygenase), whereas in animals and many bacteria it is catalysed by either membrane-bound EC 1.1.99.1 (choline dehydrogenase) or soluble EC 1.1.3.17 (choline oxidase) [5]. In some bacteria, betaine is synthesized from glycine through the actions of EC 2.1.1.156 (glycine/sarcosine N-methyltransferase) and EC 2.1.1.157 (sarcosine/dimethylglycine N-methyltransferase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9028-90-4
References:
1. Rothschild, H.A. and Barron, E.S.G. The oxidation of betaine aldehyde by betaine aldehyde dehydrogenase. J. Biol. Chem. 209 (1954) 511-523. [PMID: 13192104]
2. Livingstone, J.R., Maruo, T., Yoshida, I., Tarui, Y., Hirooka, K., Yamamoto, Y., Tsutui, N. and Hirasawa, E. Purification and properties of betaine aldehyde dehydrogenase from Avena sativa. J. Plant Res. 116 (2003) 133-140. [PMID: 12736784]
3. Muñoz-Clares, R.A., González-Segura, L., Mújica-Jiménez, C. and Contreras-Diaz, L. Ligand-induced conformational changes of betaine aldehyde dehydrogenase from Pseudomonas aeruginosa and Amaranthus hypochondriacus L. leaves affecting the reactivity of the catalytic thiol. Chem. Biol. Interact. (2003) 129-137. [PMID: 12604197]
4. Johansson, K., El-Ahmad, M., Ramaswamy, S., Hjelmqvist, L., Jornvall, H. and Eklund, H. Structure of betaine aldehyde dehydrogenase at 2.1 Å resolution. Protein Sci. 7 (1998) 2106-2117. [PMID: 9792097]
5. 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]