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Updated: Jan 17, 2026
![Radiosynthesis of 1-2-[18F]Fluoroethyl-L-Tryptophan using a One-pot, Two-step Protocol](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F63025.jpg&w=3840&q=50)
Radiosynthesis of 1-2-[18F]Fluoroethyl-L-Tryptophan using a One-pot, Two-step Protocol
Published on: September 21, 2021
Engineering Tryptophan Halogenase RebH for Regioselective Halogenation of Phenolic Compounds
Yutian Jia1, Wenhe Zhang1,2, Qizhen Wang1
1School of Life Sciences and Biopharmaceutical Sciences, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenhe, Shenyang 110016, People's Republic of China.
None:
Herein, we engineered tryptophan halogenase RebH using alanine scanning and the focused rational iterative site-specific mutagenesis (FRISM) strategy to expand its substrate scope toward phenolic compounds, particularly hydroxyquinolines and hydroxyisoquinolines, with excellent regioselectivity. The optimal mutant, 3-LSR/V80A/F111G, exhibited a 5-fold increase in catalytic activity and an 86.5-fold enhancement in catalytic efficiency (kcat/Km) for 6-hydroxyisoquinoline compared with the template 3-LSR. Furthermore, 3-LSR/V80A/F111G enabled the synthesis of 5-bromo-6-hydroxyisoquinoline on a milligram-scale with >99.9% conversion and 84.3% isolated yield.
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