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Updated: Feb 8, 2026

High-throughput Screening of Carbohydrate-degrading Enzymes Using Novel Insoluble Chromogenic Substrate Assay Kits
Published on: September 20, 2016
Sarpagan bridge enzyme has substrate-controlled cyclization and aromatization modes
Thu-Thuy T Dang1, Jakob Franke1, Ines Soares Teto Carqueijeiro2
1John Innes Centre, Department of Biological Chemistry, Norwich Research Park, Norwich, UK.
Abstract:
Cyclization reactions that create complex polycyclic scaffolds are hallmarks of alkaloid biosynthetic pathways. We present the discovery of three homologous cytochrome P450s from three monoterpene indole alkaloid-producing plants (Rauwolfia serpentina, Gelsemium sempervirens and Catharanthus roseus) that provide entry into two distinct alkaloid classes, the sarpagans and the β-carbolines. Our results highlight how a common enzymatic mechanism, guided by related but structurally distinct substrates, leads to either cyclization or aromatization.
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