Biosynthesis of tetrahydroisoquinoline scaffolds in yeast

In previous work, Saccharomyces cerevisiae was used to produce the tetrahydroisoquinoline alkaloid precursor (S)-norcoclaurine via a combination of yeast Ehrlich pathway metabolism of ʟ-tyrosine and expression of norcoclaurine synthase with a dopamine production pathway. Building on this, I developed a retrosynthetic framework to produce phenylisoquinoline, phenethylisoquinoline, and novel phenylpropylisoquinoline scaffolds. By feeding engineered yeast nonstandard amino acids, which can be metabolized by the yeast Ehrlich pathway, scaffolds for tetrahydroisoquinoline alkaloids were detected and their relative abundance quantified using mass spectrometry. Engineering many strains with different norcoclaurine synthase orthologs and feeding them different nonstandard amino acids led to the identification of orthologs which are uniquely adept at producing each class of tetrahydroisoquinoline. By selective knockout of oxidoreductase improvements in titers of phenylpropylisoquinoline were achieved. Biosynthesis of these scaffolds, the committed step in yeasts provides a crucial step in the de novo biosynthesis of tetrahydroisoquinoline compounds, providing an alternative means production.

Name thesis:degree_name

M Sc

Discipline thesis:degree_discipline

Biology

Grantor dc:publisher

The University of Western Ontario

Year dc:date.issued

2025

Author dc:creator

• Kowalski, Devin

Advisor dc:contributor.advisor

• Michael, Pyne

• norcoclaurine synthase
• synthetic biology
• metabolic engineering
• phenylisoquinoline
• phenethylisoquinoline
• phenylpropylisoquinoline

Statement dc:rights

• Attribution-NonCommercial-NoDerivatives 4.0 International

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/20.500.14721/39220

OAI identifier oai:identifier

oai:uwo.scholaris.ca:20.500.14721/39220