Research Abstract:
Our research centers on the elucidation of formation and function of plant natural products at the molecular genetic level. We focus on understanding the biosynthesis of selected natural products at the enzyme and gene levels and then exploit this knowledge for genetic engineering.
The immediate goal of our projects is the isolation of cDNAs that encode enzymes and regulators of alkaloid biosynthesis. The cDNAs are used for functional expression in heterologous systems such as bacteria or insect cell culture for biomimetic synthesis and mechanistic studies, for immunolocalization experiments in plants, and for the metabolic engineering of medicinal plants.
Regulation of these pathways at the gene and enzyme level is complex and there is much to be learned about metabolite levels and pathway interactions as we systematically over-express and suppress gene transcription through transgenesis. Today, pathway engineering in plants remains highly variable. When cellular physiology is perturbed, metabolite homeostasis and intra- and intercellular partitioning can be affected in unpredictable ways. A long-term goal of our research is directed metabolic engineering of plant natural product biosynthesis to achieve plants with tailored alkaloid profiles.
Selected Publications:
Winkler A, Kutchan TM, Macheroux P. 6-S-Cysteinylation of bi-covalently attached FAD in berberine bridge enzyme tunes the redox potential for optimal activity J Biol Chem 2007 282:24437-24443.
Winkler A, Łyskowski A, Riedl S, Puhl M, Kutchan TM, Macheroux P, Gruber K. A concerted mechanism for berberine bridge enzyme. Nat Chem Biol 2008 4:739-741.
Nomura T, Lara Quesada A, Kutchan TM. The new beta-D-glucosidase in terpenoid-isoquinoline alkaloid biosynthesis in Psychotria ipecacuanha. J Biol Chem 2008 283:34650-34659.
Grobe N, Zhang B, Fisinger U, Kutchan TM, Zenk MH, Guengerich FP. Mammalian cytochrome P450 enzymes catalyze the phenol-coupling step in endogenous morphine biosynthesis. J Biol Chem 2009 doi:10.1074/jbc.M109.011320.
Gesell A, Rolf M, Díaz Chávez ML, Huang F-C, Ziegler J, Kutchan TM. CYP719B1 is salutaridine synthase, the phenol-coupling enzyme of morphine biosynthesis in opium poppy. J Biol Chem 2009 doi:10.1074/jbc.M109.033373.
Last Updated: 08/11/2009 |