Open Collections

Kwan, Brooke D.

University of British Columbia

Biocatalysts have become increasingly prevalent in pharmaceutical production and synthetic chemistry. Among biocatalysts, alkaloid oxygenases’ ability to install reactive handles on unactivated carbons in biologically active alkaloids make them desirable biocatalytic tools for drug development and large-scale drug production. Generally, biocatalysts are identified by mining enzymes from hosts that produce, or that are grown in an environment rich in, the desired enzymatic substrate. However, hosts that neither produce nor are exposed to the desired enzymatic substrate may represent an untapped gold mine of potential biocatalysts. To identify putative alkaloid oxygenases, OrthoFinder was used to identify putative orthologs of known alkaloid oxygenases acting on the alkaloids tabersonine and ibogamine. From among these putative orthologs, three cytochrome P450s from Tabernaemontana elegans and Camptotheca acuminata were found to oxygenate the quinzoline carboline scaffold evodiamine, despite the fact that these plants are not known to produce evodiamine. These evodiamine oxygenases produced several evodiamine derivatives oxygenated at either of their terminal rings. The evodiamine oxygenase with the most diverse product profile was subjected to site-directed mutagenesis to probe the potential role of three active site residues. The unexpected activity of the evodiamine oxygenases against evodiamine suggests that plant hosts that neither produce nor are exposed to the desired enzymatic substrate may nonetheless serve as a source of efficient biocatalysts.

Text

2025-07-02

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/88642

Biochemistry and Molecular Biology

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/