Reaction: L-aspartate + O2 = iminosuccinate + H2O2
For diagram of reaction click here.
Other name(s): NadB; Laspo; AO
Systematic name: L-aspartate:oxygen oxidoreductase (deaminating)
Comments: A flavoprotein (FAD). L-Aspartate oxidase catalyses the first step in the de novo biosynthesis of NAD+ in some bacteria. O2 can be replaced by fumarate as electron acceptor, yielding succinate [5]. The ability of the enzyme to use both O2 and fumarate in cofactor reoxidation enables it to function under both aerobic and anaerobic conditions [5]. Iminosuccinate can either be hydrolysed to form oxaloacetate and NH3 or can be used by EC 2.5.1.72, quinolinate synthase, in the production of quinolinate. The enzyme is a member of the succinate dehydrogenase/fumarate-reductase family of enzymes [5].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 69106-47-4
References:
1. Nasu, S., Wicks, F.D. and Gholson, R.K. L-Aspartate oxidase, a newly discovered enzyme of Escherichia coli, is the B protein of quinolinate synthetase. J. Biol. Chem. 257 (1982) 626-632. [PMID: 7033218]
2. Mortarino, M., Negri, A., Tedeschi, G., Simonic, T., Duga, S., Gassen, H.G. and Ronchi, S. L-Aspartate oxidase from Escherichia coli. I. Characterization of coenzyme binding and product inhibition. Eur. J. Biochem. 239 (1996) 418-426. [PMID: 8706749]
3. Tedeschi, G., Negri, A., Mortarino, M., Ceciliani, F., Simonic, T., Faotto, L. and Ronchi, S. L-Aspartate oxidase from Escherichia coli. II. Interaction with C4 dicarboxylic acids and identification of a novel L-aspartate: fumarate oxidoreductase activity. Eur. J. Biochem. 239 (1996) 427-433. [PMID: 8706750]
4. Mattevi, A., Tedeschi, G., Bacchella, L., Coda, A., Negri, A. and Ronchi, S. Structure of L-aspartate oxidase: implications for the succinate dehydrogenase/fumarate reductase oxidoreductase family. Structure 7 (1999) 745-756. [PMID: 10425677]
5. Bossi, R.T., Negri, A., Tedeschi, G. and Mattevi, A. Structure of FAD-bound L-aspartate oxidase: insight into substrate specificity and catalysis. Biochemistry 41 (2002) 3018-3024. [PMID: 11863440]
6. Katoh, A., Uenohara, K., Akita, M. and Hashimoto, T. Early steps in the biosynthesis of NAD in Arabidopsis start with aspartate and occur in the plastid. Plant Physiol. 141 (2006) 851-857. [PMID: 16698895]