title: Heterologous expression of two FAD-dependent oxidases with (S)-tetrahydroprotoberberine oxidase activity from Arge mone mexicana and Berberis wilsoniae in insect cells.
abstract: Berberine, palmatine and dehydrocoreximine are end products of protoberberine biosynthesis. These quaternary protoberberines are elicitor inducible and, like other phytoalexins, are highly oxidized. The oxidative potential of these compounds is derived from a diverse array of biosynthetic steps involving hydroxylation, intra-molecular C-C coupling, methylenedioxy bridge formation and a dehydrogenation reaction as the final step in the biosynthesis. For the berberine biosynthetic pathway, the identification of the dehydrogenase gene is the last remaining uncharacterized step in the elucidation of the biosynthesis at the gene level. An enzyme able to catalyze these reactions, (S)-tetrahydroprotoberberine oxidase (STOX, EC 1.3.3.8), was originally purified in the 1980s from suspension cells of Berberis wilsoniae and identified as a flavoprotein (Amann et al. 1984). We report enzymatic activity from recombinant STOX expressed in Spodoptera frugiperda Sf9 insect cells. The coding sequence was derived successively from peptide sequences of purified STOX protein. Furthermore, a recombinant oxidase with protoberberine dehydrogenase activity was obtained from a cDNA library of Argemone mexicana, a traditional medicinal plant that contains protoberberine alkaloids. The relationship of the two enzymes is discussed regarding their enzymatic activity, phylogeny and the alkaloid occurrence in the plants. Potential substrate binding and STOX-specific amino acid residues were identified based on sequence analysis and homology modeling.
authors.affiliation: Leibniz-Institut für Pflanzenbiochemie, Halle (Saale), Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Gesell
authors.forename: Maria Luisa Díaz
authors.initials: ML
authors.lastname: Chávez
authors.forename: Robert
authors.initials: R
authors.lastname: Kramell
authors.forename: Markus
authors.initials: M
authors.lastname: Piotrowski
authors.forename: Peter
authors.initials: P
authors.lastname: Macheroux
authors.forename: Toni M
authors.initials: TM
authors.lastname: Kutchan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D031674:Argemone / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001600:Berberine Alkaloids / Q000378:metabolism; D028142:Berberis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D005420:Flavoproteins / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007313:Insecta / Q000201:enzymology / Q000235:genetics; D008969:Molecular Sequence Data; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D017385:Sequence Homology; D012717:Sesquiterpenes / Q000378:metabolism; D014170:Transformation, Genetic; D000094162:Phytoalexins
chemical_list: D001600:Berberine Alkaloids; D005420:Flavoproteins; D011994:Recombinant Proteins; D012717:Sesquiterpenes; D044925:Oxidoreductases Acting on CH-CH Group Donors; C056768:tetrahydroprotoberberine oxidase; D000094162:Phytoalexins