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Water-based coupling of amino acids for sustainable solid-phase peptide synthesis

Nature Sustainability (2026)Cite this article

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Abstract

Solid-phase peptide synthesis (SPPS) is a primary source of peptides for structure–function studies in development of potential clinical, agricultural, veterinary or cosmetic applications. Despite its efficiency and scalability, SPPS produces unsustainable volumes of toxic waste and non-degradable solid supports. With regulatory changes now in effect to reduce solvent use, there is a pressing need for sustainable, water-based synthesis methods. Due to the aqueous insolubility of the commonly employed Nα-Fmoc-amino acids—the primary building blocks in SPPS—establishing water-based peptide synthesis protocols is extremely challenging. Here we show that amine salts of, for example, N-methylmorpholine or N,N,N-triethanolamine and Nα-Fmoc protected amino acids are water soluble at high concentrations. Activation with a pre-formed water-soluble activating agent enables high quality SPPS on a hydrophilic and biodegradable poly-ε-lysine-based solid support in aqueous solution without characteristic side reactions. The presented methodology provides a simple avenue to sustainable, scalable water-based chemical synthesis of peptides.

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Fig. 1: Fmoc-amino acid dissolution with NMM and dilution with water and Fmoc-amino acid crystal structure with NMM and TEOA.
Fig. 2: Scheme of proposed acylation of resin-bound amines with Fmoc-amino acids during aqueous solid-phase peptide synthesis.
Fig. 3: General scheme for the SpheriTide Aq and Aq-M resin derivatization and repetitive aqueous-based SPPS.
Fig. 4: RP-HPLC of crude-cleaved synthetic peptides prepared by aqueous SPPS on SpheriTide Aq and Aq-M.

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Data availability

All data supporting the findings of this study are available within this Article and its Supplementary Information. Crystallographic data for the structures reported in this paper have been deposited at the Cambridge Crystallographic Data Centre (CCDC), under deposition numbers 2402790–2402791. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/structures.

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Acknowledgements

The electron diffraction experiments were supported by Novo Nordisk Foundation Research Infrastructure grant number NNF220C0074439 (A.L.). M.M. was supported by NNF22SA0081975 and Villum Foundation 00056577. This work was also partly supported by an Australian Research Council Linkage grant (LP180101006) to J.D.W., M.A.H. and D.A.W. Studies at the Florey Institute of Neuroscience and Mental Health were also supported by the Victorian Government’s Operational Infrastructure Support Program. D.A.W., M.M. and J.D.W. gratefully acknowledge R. C. Sheppard (deceased) and E. Atherton, who made seminal contributions to the development of Fmoc-based SPPS and provided formative postdoctoral and professional opportunities that greatly influenced and enabled the authors’ enduring contributions to the field.

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Authors and Affiliations

  1. SpheriTech Ltd, Runcorn, UK

    Donald A. Wellings, Joshua Greenwood, Ian Thomas & Colin Hughes

  2. Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia

    Wenyi Li

  3. Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia

    Feng Lin, Mohammed Akhter Hossain & John D. Wade

  4. School of Chemistry, University of Melbourne, Melbourne, Victoria, Australia

    Mohammed Akhter Hossain & John D. Wade

  5. Department of Chemistry, University of Copenhagen, Copenhagen, Denmark

    Arianna Lanza

  6. Department of Chemistry, Centre for Evolutionary Chemical Biology, University of Copenhagen, Copenhagen, Denmark

    Morten Meldal

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Contributions

This study was conceived by D.A.W., M.M. and J.D.W., who designed the research and analysed the data. Experiments were prepared and performed by D.A.W., J.G, I.T., C.H., W.L., F.L., M.A.H. and J.D.W. (peptide chemistry), M.M. (peptide chemistry, NMR) and A.L. (crystallography). The manuscript was drafted by D.A.W., A.L., M.M. and J.W.D. All authors contributed to the discussion and finalization of the paper.

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Correspondence to Donald A. Wellings, Morten Meldal or John D. Wade.

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D.A.W. is the Managing Director of SpheriTech Ltd. J.D.W. is an unpaid member of the Scientific Advisory Board of SpheriTech Ltd. The remaining authors declare no competing interests.

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Nature Sustainability thanks William Lubell, Beatriz G. de la Torre, and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

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Wellings, D.A., Greenwood, J., Thomas, I. et al. Water-based coupling of amino acids for sustainable solid-phase peptide synthesis. Nat Sustain (2026). https://doi.org/10.1038/s41893-025-01761-z

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