Alanine dehydrogenase

Alanine dehydrogenase (EC 1.4.1.1) is an enzyme that catalyzes the chemical reaction

L-alanine + H₂O + NAD⁺ pyruvate + NH₃ + NADH + H⁺

The 3 substrates of this enzyme are L-alanine, water, and nicotinamide adenine dinucleotide⁺, whereas its 4 products are pyruvate, ammonia, NADH, and hydrogen ion.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH₂ group of donors with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is L-alanine:NAD⁺ oxidoreductase (deaminating). Other names in common use include AlaDH, L-alanine dehydrogenase, NAD⁺-linked alanine dehydrogenase, alpha-alanine dehydrogenase, NAD⁺-dependent alanine dehydrogenase, alanine oxidoreductase, and NADH-dependent alanine dehydrogenase. This enzyme participates in taurine and hypotaurine metabolism and reductive carboxylate cycle (CO₂ fixation).

Structural studies

As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes 1OMO, 1PJB, 1PJC, 1SAY, 1VLL, and 2EEZ.

References

• O'Connor RJ and Halvorson H (1961). "The substrate specificity of L-alanine dehydrogenase". Biochim. Biophys. Acta 48 (1): 47–55. doi:10.1016/0006-3002(61)90513-3. PMID 13730044. 
• Pierard A and Wiame JM (1960). "Proprietes de la L(+)-alanine-deshydrogenase". Biochim. Biophys. Acta 37 (3): 490–502. doi:10.1016/0006-3002(60)90506-0. 
• Yoshida A and Freese E (1965). "Enzymic properties of alanine dehydrogenase of Bacillus subtilis". Biochim. Biophys. Acta 96: 248–262. doi:10.1016/0926-6593(65)90009-3. PMID 14298830.