Identification of a Noroxomaritidine Reductase with Amaryllidaceae Alkaloid Biosynthesis Related Activities.Kilgore, M.B., Holland, C.K., Jez, J.M., Kutchan, T.M.
(2016) J.Biol.Chem. 291: 16740-16752
- PubMed: 27252378
- DOI: 10.1074/jbc.M116.717827
- Primary Citation of Related Structures:
- PubMed Abstract:
Amaryllidaceae alkaloids are a large group of plant natural products with over 300 documented structures and diverse biological activities. Several groups of Amaryllidaceae alkaloids including the hemanthamine- and crinine-type alkaloids show promise ...
Amaryllidaceae alkaloids are a large group of plant natural products with over 300 documented structures and diverse biological activities. Several groups of Amaryllidaceae alkaloids including the hemanthamine- and crinine-type alkaloids show promise as anticancer agents. Two reduction reactions are required for the production of these compounds: the reduction of norcraugsodine to norbelladine and the reduction of noroxomaritidine to normaritidine, with the enantiomer of noroxomaritidine dictating whether the derivatives will be the crinine-type or hemanthamine-type. It is also possible for the carbon-carbon double bond of noroxomaritidine to be reduced, forming the precursor for maritinamine or elwesine depending on the enantiomer reduced to an oxomaritinamine product. In this study, a short chain alcohol dehydrogenase/reductase that co-expresses with the previously discovered norbelladine 4'-O-methyltransferase from Narcissus sp. and Galanthus spp. was cloned and expressed in Escherichia coli Biochemical analyses and x-ray crystallography indicates that this protein functions as a noroxomaritidine reductase that forms oxomaritinamine from noroxomaritidine through a carbon-carbon double bond reduction. The enzyme also reduces norcraugsodine to norbelladine with a 400-fold lower specific activity. These studies identify a missing step in the biosynthesis of this pharmacologically important class of plant natural products.
From the Donald Danforth Plant Science Center, St. Louis, Missouri 63132 and the Department of Biology, Washington University in St. Louis, St. Louis, Missouri 63130.