|
type |
Journal Article |
authors |
Takechi, M.; Kanda, M.; Hori, K.; Kurotsu, T.; Saito, Y. |
title |
Purification and properties of L-ornithine delta-aminotransferase from gramicidin S-producing Bacillus brevis |
journal |
J Biochem (Tokyo) |
Activity |
2.6.1.13 |
ui |
95204401 |
year |
(1994) |
volume |
116 |
number |
5 |
pages |
955-9. |
| |
keywords |
Amino Acid Sequence |
abstract |
In gramicidin S-producing Bacillus brevis, the addition of L-ornithine to the minimal medium with L-glutamate as the sole carbon and nitrogen source caused an 8-fold induction of L-ornithine delta-aminotransferase [EC 2.6.1.13]. The enzyme was purified to homogeneity. The native enzyme had a molecular weight of about 88,000 after gel filtration and consisted of two subunits with an identical in molecular weight of about 45,000. The enzyme was specific for L-ornithine (Km = 1.05 mM) as an amino donor and for 2-oxoglutarate (Km = 6.25 mM) as an amino acceptor, and catalyzed the conversion of L-ornithine and 2- oxoglutarate, respectively, to glutamic-gamma-semialdehyde, which is spontaneously cyclized to delta 1-pyrroline-5-carboxylate and L- glutamate. The enzyme exhibits an absorption maximum at 425 nm at neutral pH, and 1 mol of pyridoxal phosphate is bound per subunit. The enzyme activity was irreversibly inhibited by gabaculine, and L- ornithine protected the enzyme from the inhibition. The N-terminal amino acid sequence revealed a noteworthy similarity between human and yeast L-ornithine delta-aminotransferases in residues 17-28 of the B. brevis enzyme. |
last changed |
2002/11/04 17:41 |
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