Biocatalytic cascades enable manufacture of the macrocyclic peptide enlicitide
Editor’s summary
Macrocyclic peptides are formed by linking together parts of a peptide, which provides conformational rigidity, binding specificity, and protease resistance that make these molecules attractive for drug design. Chemical synthesis of these peptides can be very challenging due to their complex structure and the potential for competing reactions. Klapars et al. developed a biocatalytic approach to produce the complex macrocyclic drug enlicitide, which is under investigation for the prevention of atherosclerotic cardiovascular disease (see the Perspective by Buller and Pelletier). Using ATP-dependent ligases and transacylation by a hydrolase, the authors assembled a large fragment containing the first macrolactam ring. They then combined this fragment with two chemically synthesized fragments in a five-enzyme cascade and a chemoenzymatic step. The resulting synthesis is exceptionally efficient, avoids protecting groups, and is optimized for multikilogram-scale production with an overall yield of around 40%. —Michael A. Funk
Abstract
Historically, many compelling therapeutic targets have been accessible only by injectable biologic drugs. Macrocyclic peptides, such as the proprotein convertase subtilisin/kexin type 9 inhibitor enlicitide for the treatment of atherosclerotic cardiovascular disease, are beginning to unlock these targets to orally administered therapies to enable broader patient access. We report the convergent biocatalytic assembly of enlicitide from simple building blocks enabled by a suite of engineered enzymes to catalyze selective peptide fragment formation, coupling, and macrocyclization in a protecting group–free manner. Together with efficient crystallizations that obviate the need for chromatography, this approach reduces the number of steps by greater than half compared with prior state-of-the-art methods, addressing long-standing synthetic challenges and offering a sustainable blueprint for the scalable development of complex peptide therapeutics.
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References and Notes
1
L. Wang, N. Wang, W. Zhang, X. Cheng, Z. Yan, G. Shao, X. Wang, R. Wang, C. Fu, Therapeutic peptides: Current applications and future directions. Signal Transduct. Target. Ther. 7, 48 (2022).
2
K. R. Campos, P. J. Coleman, J. C. Alvarez, S. D. Dreher, R. M. Garbaccio, N. K. Terrett, R. D. Tillyer, M. D. Truppo, E. R. Parmee, The importance of synthetic chemistry in the pharmaceutical industry. Science 363, eaat0805 (2019).
3
I. Kekessie, K. Wegner, I. Martinez, M. E. Kopach, T. D. White, J. K. Tom, M. N. Kenworthy, F. Gallou, J. Lopez, S. G. Koenig, P. R. Payne, S. Eissler, B. Arumugam, C. Li, S. Mukherjee, A. Isidro-Llobet, O. Ludemann-Hombourger, P. Richardson, J. Kittelmann, D. Sejer Pedersen, L. J. van den Bos, Process Mass Intensity (PMI): A Holistic Analysis of Current Peptide Manufacturing Processes Informs Sustainability in Peptide Synthesis. J. Org. Chem. 89, 4261–4282 (2024).
4
A. Isidro-Llobet, M. N. Kenworthy, S. Mukherjee, M. E. Kopach, K. Wegner, F. Gallou, A. G. Smith, F. Roschangar, Sustainability Challenges in Peptide Synthesis and Purification: From R&D to Production. J. Org. Chem. 84, 4615–4628 (2019).
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Science
Volume 392 | Issue 6798
7 May 2026
7 May 2026
Copyright
Copyright © 2026 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
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Submission history
Received: 17 December 2025
Accepted: 4 March 2026
Published in print: 7 May 2026
Acknowledgments
We acknowledge the help and support of the following people: D. Zewge, C. Li, J. Y. Kong, N. Aminoleslami, M. Modi, M. Lin, and X. Yin for analysis and characterization; S. Ruccolo for process understanding experiments; A. M. Makarewicz, A. Owens, J. Gouker, X. Fu, J. Knight, K. Sharp, and J. Zuk for supporting protein engineering; R. Desmond, R. Varsolona, I. Lee, P. Patel, V. L. Schultz, and R. D. Franklin for reaction scale-up and crystallization experiments.
Funding:
This work was funded by Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.
Author Contributions:
Conception and design of the work: L.C.C., K.R.C., C.K.C., R.M.F., Y.H., M.H.K., K.M.M., R.T.R., and D.A.T. Conception and design and acquisition, analysis and interpretation of data: A.K., A.F., S.G., O.A., E.Y.A., N.A., C.A., S.A., T.M.A., R.S.A., R.C.B., M.R.Ba, M.R.Be., K.M.B., L.B., J.K.B.C., K.C.S., A.C., H.Y.D.C., M.C., Z.C., W.L.C.L., S.W.C., S.S.C., R.D.C., S.M.D., G.D.P., T.D., S.D.D., R.J.D., N.P.D., Y.F., J.H.F., S.P.F., J.C.G., D.R.G., A.A.G., J.W.G., N.H., H.M.H., X.H., M.H., C.H., E.H., K.Hi., H.I.H., C.M.H., A.H., H.H., K.Hu., A.M.H., T.I., C.M.J., W.O.J., K.K., J.L.K., J.N.K., B.Ko., S.K., J.K., B.Kr. J.T.K., T.T.K., A.Y.L., J.Le., Q.L., S.L., J.Li., W.L., G.L., E.M., P.E.M., E.L.M., J.A.M., S.M.V., M.Mi., M.Mo., J.C.M., D.M., G.S.M., J.V.O., W.P., J.P., A.P., T.Pe., B.K.P., T.Pi., C.A.P.S., C.K.P., A.K.P., Y.Q., E.L.R., M.R., N.R.R., S.A.R., L.R., S.R., K.A.R., C.H.R., E.L.S., A.N.S., E.S., A.C.S., W.Ta., D.A.T., N.T., W.To., V.T., R.T., Q.T., B.W.H.T., O.U., D.A.V., J.E.V., D.V., H.W., T.W., X.W., Y.W., Z.W., M.S.W., C.W., B.M.W., K-.J.X., Y.X., J.-X.Y., H.Y., V.Z., Y.Z., M.Z., and W.Z. Writing – original draft: A.K., A.F., and S.G. Writing – review & editing: C.A., K.C.S., L.-C.C., K.R.C., M.C., S.W.C., S.S.C., S.M.D., D.R.G., C.M.H., T.I., K.M.M., J.A.M., R.T.R., and D.A.T.
Competing Interests:
Data, Code, and Materials Availability:
All data necessary to evaluate and reproduce this work are available in the main text or the SM. Synthetic procedures are provided to generate all newly reported materials. Newly created materials are available upon request through a Material Transfer Agreement between Merck & Co., Inc. and the requesting institution, which must be able to accept regulated materials. No new code was generated in the course of this study.
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Copyright © 2026 the authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original US government works. https://www.science.org/content/page/science-licenses-journal-article-reuse
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Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA
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