Editor: Sergio Casella
A novel strategy for enzymatic synthesis of 4-hydroxyisoleucine: identification of an enzyme possessing HMKP (4-hydroxy-3-methyl-2-keto-pentanoate) aldolase activity
Article first published online: 6 JUN 2007
FEMS Microbiology Letters
Volume 273, Issue 1, pages 70–77, August 2007
How to Cite
Smirnov, S. V., Samsonova, N. N., Novikova, A. E., Matrosov, N. G., Rushkevich, N. Y., Kodera, T., Ogawa, J., Yamanaka, H. and Shimizu, S. (2007), A novel strategy for enzymatic synthesis of 4-hydroxyisoleucine: identification of an enzyme possessing HMKP (4-hydroxy-3-methyl-2-keto-pentanoate) aldolase activity. FEMS Microbiology Letters, 273: 70–77. doi: 10.1111/j.1574-6968.2007.00783.x
- Issue published online: 7 JUN 2007
- Article first published online: 6 JUN 2007
- Received 16 November 2006; revised 8 April 2007; accepted 26 April 2007.First published online 7 June 2007.
- type II diabetes;
- HpcH/HpaI aldolase family
A two-step enzymatic synthesis process of 4-hydroxyisoleucine is suggested. In the first step, the aldol condensation of acetaldehyde and α-ketobutyrate catalyzed by specific aldolase results in the formation of 4-hydroxy-3-methyl-2-keto-pentanoate (HMKP). In the second step, amination of HMKP by the branched-chain amino acid aminotransferase leads to synthesis of 4-hydroxyisoleucine. An enzyme possessing HMKP aldolase activity (asHPAL) was purified 2500-fold from a crude extract of Arthrobacter simplex strain AKU 626. Sequencing of the asHPAL structural gene showed that the purified enzyme belongs to the HpcH/HpaI aldolase family. The 4-hydroxyisoleucine was synthesized in vitro from acetaldehyde, α-ketobutyrate and l-glutamate using a coupled aldolase/branched-chain amino acid aminotransferase bienzymatic reaction.