Work

Enzymatic Bromination of Native Peptides for Late-Stage Structural Diversification via Suzuki–Miyaura Coupling

Year: 2026

Type: article

Abstract: Flavin-dependent halogenases (FDHs) provide a biocatalytic approach for the site-selective halogenation of aromatic compounds, but their use in late-stage functionalization of peptides has remained limited. Here, we show that tryptophan (Trp) 7-halogenase RebH and an engineered variant (4V) originally optimized for larger small-molecule scaffolds can brominate peptidyl-Trp residues across a broad range of sequences and positional contexts. Through extensive analysis of diverse substrate sequences, we define features that enable RebH activity and reveal 4V's expanded sequence tolerance. We applied 4V for enzymatic bromination of diverse bioactive peptide scaffolds, including an antimicrobial peptide, a cell-penetrating peptide, and a G protein-coupled receptor agonist, without the need for sequence modification. These brominated peptides served as substrates for Suzuki-Miyaura coupling, enabling the installation of modifications that conferred new functional properties or tuned the biological activity of these peptides. Our results expand the substrate landscape of FDHs and establish bromination-enabled cross-coupling as a general approach for late-stage diversification of bioactive peptides.

Source: ACS Chemical Biology

DOI: 10.1021/acschembio.6c00269

Authors: Haley N. Bridge, Chase L. Radziej, Amy M. Weeks

Institution: University of Wisconsin–Madison

Language: English

Topic: Enzyme Catalysis and Immobilization

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: National Science Foundation, University of Wisconsin-Madison, National Institutes of Health, National Institute of General Medical Sciences