Download MendeleyEnzymatic combinatorial synthesis of E-64 and related cysteine protease inhibitors.
Liu, M., Zang, X., Vlahakis, N.W., Rodriguez, J.A., Ohashi, M., Tang, Y.(2025) Nat Chem Biol
- PubMed: 40346252
- DOI: https://doi.org/10.1038/s41589-025-01907-2
- Primary Citation of Related Structures:
9CJN, 9CKT, 9CKW, 9CKY, 9CLH, 9EG7 - PubMed Abstract:
E-64 is an irreversible cysteine protease inhibitor prominently used in chemical biology and drug discovery. Here we uncover a nonribosomal peptide synthetase-independent biosynthetic pathway for E-64, which is widely conserved in fungi. The pathway starts with epoxidation of fumaric acid to the warhead (2S,3S)-trans-epoxysuccinic acid with an Fe(II)/α-ketoglutarate-dependent oxygenase, followed by successive condensation with an L-amino acid by an adenosine triphosphate grasp enzyme and with an amine by the fungal example of amide bond synthetase. Both amide bond-forming enzymes display notable biocatalytic potential, including scalability, stereoselectivity toward the warhead and broader substrate scopes in forming the amide bonds. Biocatalytic cascade with these amide bond-forming enzymes generated a library of cysteine protease inhibitors, leading to more potent cathepsin inhibitors. Additionally, one-pot reactions enabled the preparative synthesis of clinically relevant inhibitors. Our work highlights the importance of biosynthetic investigation for enzyme discovery and the potential of amide bond-forming enzymes in synthesizing small-molecule libraries.
Organizational Affiliation:
Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, USA.
