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Synthesis of ?-Branched Tryptophan Analogues Using an Engineered Subunit of Tryptophan Synthase.

ABSTRACT: We report that l-threonine may substitute for l-serine in the ?-substitution reaction of an engineered subunit of tryptophan synthase from Pyrococcus furiosus, yielding (2S,3S)-?-methyltryptophan (?-MeTrp) in a single step. The trace activity of the wild-type ?-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 ?-MeTrp in nature and offers a simple and expandable route to preparing derivatives of this valuable building block.

SUBMITTER: Herger M

PROVIDER: S-EPMC4948191 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature

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Synthesis of β-Branched Tryptophan Analogues Using an Engineered Subunit of Tryptophan Synthase.

Herger Michael M van Roye Paul P Romney David K DK Brinkmann-Chen Sabine S Buller Andrew R AR Arnold Frances H FH

Journal of the American Chemical Society 20160701 27

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 engineer ...[more]

PMID: 27355405

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