Synthesis of β-Branched Tryptophan Analogues Using an Engineered Subunit of Tryptophan Synthase
Abstract
We report that l-threonine may substitute for l-serine in the β-substitution reaction of an engineered subunit of tryptophan synthase from Pyrococcus furiosus, yielding (2S,3S)-β-methyltryptophan (β-MeTrp) in a single step. The trace activity of the wild-type β-subunit on this substrate was enhanced more than 1000-fold by directed evolution. Structural and spectroscopic data indicate that this increase is correlated with stabilization of the electrophilic aminoacrylate intermediate. The engineered biocatalyst also reacts with a variety of indole analogues and thiophenol for diastereoselective C–C, C–N, and C–S bond-forming reactions. This new activity circumvents the 3-enzyme pathway that produces β-MeTrp in nature and offers a simple and expandable route to preparing derivatives of this valuable building block.
Additional Information
© 2016 American Chemical Society. Received: May 10, 2016; Publication Date (Web): June 29, 2016. The authors thank Hans Renata, Javier Murciano-Calles, and Chris Prier for helpful discussion and comments on the manuscript. We thank Dr. Jens Kaiser of the Caltech Molecular Observatory, which is supported by the Gordon and Betty Moore Foundation, the Beckman Institute, and the Sanofi-Aventis Bioengineering Research Program at Caltech. We thank Dr. Scott Virgil and the Center for Catalysis and Chemical Synthesis, and Dr. Mona Shahgholi and Naseem Torian from the Caltech Mass Spectrometry Laboratory. This work was funded through the Jacobs Institute for Molecular Engineering for Medicine and Ruth Kirschstein NIH Postdoctoral Fellowships F32G110851 (to A.R.B.) and F32GM117635 (to D.K.R.). M.H. and P.vR. contributed equally. The authors declare no competing financial interest.Attached Files
Accepted Version - nihms799555.pdf
Supplemental Material - ja6b04836_si_001.pdf
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Additional details
- Alternative title
- Synthesis of β-branched tryptophan analogs using an engineered subunit of tryptophan synthase
- PMCID
- PMC4948191
- Eprint ID
- 68843
- DOI
- 10.1021/jacs.6b04836
- Resolver ID
- CaltechAUTHORS:20160706-081124141
- Jacobs Institute for Molecular Engineering for Medicine
- NIH Postdoctoral Fellowship
- F32G110851
- NIH Postdoctoral Fellowship
- F32GM117635
- Gordon and Betty Moore Foundation
- Caltech Beckman Institute
- Sanofi-Aventis Bioengineering Research Program
- Created
-
2016-07-06Created from EPrint's datestamp field
- Updated
-
2022-04-26Created from EPrint's last_modified field
- Caltech groups
- Jacobs Institute for Molecular Engineering for Medicine