Engineering Saccharomyces cerevisiae for the de novo Production of Halogenated Tryptophan and Tryptamine Derivatives

Abstract

The indole scaffold is a recurring structure in multiple bioactive heterocycles and natural products. Substituted indoles like the amino acid tryptophan serve as a precursor for a wide range of natural products with pharmaceutical or agrochemical applications. Inspired by the versatility of these compounds, medicinal chemists have for decades exploited indole as a core structure in the drug discovery process. With the aim of tuning the properties of lead drug candidates, regioselective halogenation of the indole scaffold is a common strategy. However, chemical halogenation is generally expensive, has a poor atom economy, lacks regioselectivity, and generates hazardous waste streams. As an alternative, in this work we engineer the industrial workhorse Saccharomyces cerevisiae for the de novo production of halogenated tryptophan and tryptamine derivatives. Functional expression of bacterial tryptophan halogenases together with a partner flavin reductase and a tryptophan decarboxylase resulted in the production of halogenated tryptophan and tryptamine with chlorine or bromine. Furthermore, by combining tryptophan halogenases, production of di‐halogenated molecules was also achieved. Overall, this works paves the road for the production of new‐to‐nature halogenated natural products in yeast.

Yeast Platforms for Production and Screening of Bioactive Derivatives of Rauwolscine

“…These results confirmed that in each case only a single chlorotryptophan was present in detectable amounts in the broth. This is in keeping with other recent work on halogenase expression in yeast. , Aside from some variability when coexpressing Eco Frb from Escherichia coli, the activity of these three FDHs did not vary significantly between reductases and Eco SsuE from E. coli was selected for further experiments.…”

A comprehensive review and comparison of L-tryptophan biosynthesis in Saccharomyces cerevisiae and Escherichia coli

“…Integration of S. cerevisiae ST7574 (CEN.PK113-7D) with SrPyrH , SttH , and LaRebH . The highest titers obtained for halogenated tryptophan and tryptamine were 3.56 ± 0.24 mg/L 7-bromotryptophan and 2.42 ± 0.31 mg/L 7-chlorotryptamine ( Milne et al, 2023 ).…”