Lysine 6-dehydrogenase explained

Lysine 6-dehydrogenase
Ec Number:	1.4.1.18
Cas Number:	89400-30-6

Lysine 6-dehydrogenase (L-lysine epsilon-dehydrogenase, L-lysine 6-dehydrogenase, LysDH) is an enzyme with systematic name L-lysine:NAD⁺ 6-oxidoreductase (deaminating).^{[1] [2] [3] [4]} This enzyme catalyses the following chemical reaction

L-lysine + NAD⁺

\rightleftharpoons (S)-2,3,4,5-tetrahydropyridine-2-carboxylate + NADH + H⁺ + NH₃ (overall reaction)

(1a) L-lysine + NAD⁺ + H₂O

\rightleftharpoons (S)-2-amino-6-oxohexanoate + NADH + H⁺ + NH₃

(1b) (S)-2-amino-6-oxohexanoate

\rightleftharpoons (S)-2,3,4,5-tetrahydropyridine-2-carboxylate + H₂O (spontaneous)

The enzyme is highly specific for L-lysine as substrate, although S-(2-aminoethyl)-L-cysteine can act as a substrate, but more slowly.

Notes and References

1. Misono H, Nagasaki S . Occurrence of L-lysine epsilon-dehydrogenase in Agrobacterium tumefaciens . Journal of Bacteriology . 150 . 1 . 398–401 . April 1982 . 10.1128/jb.150.1.398-401.1982 . 6801024 . 220128 .
2. Purification and properties of L-lysine ε-dehydrogenase from Agrobacterium tumefaciens . Misono H, Uehigashi H, Morimoto E, Nagasaki S . Agric. Biol. Chem. . 1985 . 49 . 7 . 2253–2255 . 10.1271/bbb1961.49.2253. free .
3. Misono H, Hashimoto H, Uehigashi H, Nagata S, Nagasaki S . Properties of L-lysine epsilon-dehydrogenase from Agrobacterium tumefaciens . Journal of Biochemistry . 105 . 6 . 1002–8 . June 1989 . 10.1093/oxfordjournals.jbchem.a122757 . 2768207 .
4. Heydari M, Ohshima T, Nunoura-Kominato N, Sakuraba H . Highly stable L-lysine 6-dehydrogenase from the thermophile Geobacillus stearothermophilus isolated from a Japanese hot spring: characterization, gene cloning and sequencing, and expression . Applied and Environmental Microbiology . 70 . 2 . 937–42 . February 2004 . 14766574 . 348916 . 10.1128/aem.70.2.937-942.2004 . 2004ApEnM..70..937H .