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Abiotic reduction of ketones with silanes catalysed by carbonic anhydrase through an enzymatic zinc hydride

Abstract

Enzymatic reactions through mononuclear metal hydrides are unknown in nature, despite the prevalence of such intermediates in the reactions of synthetic transition-metal catalysts. If metalloenzymes could react through abiotic intermediates like these, then the scope of enzyme-catalysed reactions would expand. Here we show that zinc-containing carbonic anhydrase enzymes catalyse hydride transfers from silanes to ketones with high enantioselectivity. We report mechanistic data providing strong evidence that the process involves a mononuclear zinc hydride. This work shows that abiotic silanes can act as reducing equivalents in an enzyme-catalysed process and that monomeric hydrides of electropositive metals, which are typically unstable in protic environments, can be catalytic intermediates in enzymatic processes. Overall, this work bridges a gap between the types of transformation in molecular catalysis and biocatalysis.

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Fig. 1: Structure and catalytic mechanism of human carbonic anhydrase.
Fig. 2: Catalytic reduction of ketones with hCAII in whole cells.
Fig. 3: Mechanistic study of the reduction of ketone catalysed by carbonic anhydrase.
Fig. 4: Computational study of hydride generation and transfer.

Data availability

The data supporting the findings of this study are available within the article and its Supplementary Information.

References

  1. 1.

    Schwizer, F. et al. Artificial metalloenzymes: Reaction scope and optimization strategies. Chem. Rev. 118, 142–231 (2018).

    CAS  Article  Google Scholar 

  2. 2.

    Rosati, F. & Roelfes, G. Artificial metalloenzymes. ChemCatChem 2, 916–927 (2010).

    CAS  Article  Google Scholar 

  3. 3.

    Coelho, P. S., Brustad, E. M., Kannan, A. & Arnold, F. H. Olefin cyclopropanation via carbene transfer catalyzed by engineered cytochrome P450 enzymes. Science 339, 307–310 (2013).

    CAS  Article  Google Scholar 

  4. 4.

    Key, H. M. et al. Beyond iron: Iridium-containing P450 enzymes for selective cyclopropanations of structurally diverse alkenes. ACS Cent. Sci. 3, 302–308 (2017).

    CAS  Article  Google Scholar 

  5. 5.

    Key, H. M., Dydio, P., Clark, D. S. & Hartwig, J. F. Abiological catalysis by artificial haem proteins containing noble metals in place of iron. Nature 534, 534–537 (2016).

    CAS  Article  Google Scholar 

  6. 6.

    Kan, S. B. J., Lewis, R. D., Chen, K. & Arnold, F. H. Directed evolution of cytochrome c for carbon–silicon bond formation: Bringing silicon to life. Science 354, 1048–1051 (2016).

    CAS  Article  Google Scholar 

  7. 7.

    Green, M. L. H. A new approach to the formal classification of covalent compounds of the elements. J. Organomet. Chem. 500, 127–148 (1995).

    CAS  Article  Google Scholar 

  8. 8.

    Jing, Q. & Kazlauskas, R. J. Regioselective hydroformylation of styrene using rhodium-substituted carbonic anhydrase. ChemCatChem 2, 953–957 (2010).

    CAS  Article  Google Scholar 

  9. 9.

    Horitani, M. et al. Radical SAM catalysis via an organometallic intermediate with an Fe-[5′-C]-deoxyadenosyl bond. Science 352, 822–825 (2016).

  10. 10.

    Gloaguen, F. & Rauchfuss, T. B. Small molecule mimics of hydrogenases: hydrides and redox. Chem. Soc. Rev. 38, 100–108 (2009).

    CAS  Article  Google Scholar 

  11. 11.

    Skander, M. et al. Artificial metalloenzymes: (strept)avidin as host for enantioselective hydrogenation by achiral biotinylated rhodium−diphosphine complexes. J. Am. Chem. Soc. 126, 14411–14418 (2004).

    CAS  Article  Google Scholar 

  12. 12.

    Lin, C.-C., Lin, C.-W. & Chan, A. S. C. Catalytic hydrogenation of itaconic acid in a biotinylated Pyrphos–rhodium(I) system in a protein cavity. Tetrahedron Asymmetry 10, 1887–1893 (1999).

    CAS  Article  Google Scholar 

  13. 13.

    Rebelein, J. G., Cotelle, Y., Garabedian, B. & Ward, T. R. Chemical optimization of whole-cell transfer hydrogenation using carbonic anhydrase as host protein. ACS Catal. 9, 4173–4178 (2019).

    CAS  Article  Google Scholar 

  14. 14.

    Chevalley, A., Cherrier, M. V., Fontecilla-Camps, J. C., Ghasemi, M. & Salmain, M. Artificial metalloenzymes derived from bovine β-lactoglobulin for the asymmetric transfer hydrogenation of an aryl ketone – synthesis, characterization and catalytic activity. Dalton Trans. 43, 5482–5489 (2014).

    CAS  Article  Google Scholar 

  15. 15.

    Merkler, D. J. & Schramm, V. L. Catalytic mechanism of yeast adenosine 5′-monophosphate deaminase. Zinc content, substrate specificity, pH studies, and solvent isotope effects. Biochemistry 32, 5792–5799 (1993).

    CAS  Article  Google Scholar 

  16. 16.

    Håkansson, K., Carlsson, M., Svensson, L. A. & Liljas, A. Structure of native and apo carbonic anhydrase II and structure of some of its anion-ligand complexes. J. Mol. Biol. 227, 1192–1204 (1992).

    Article  Google Scholar 

  17. 17.

    Friedfeld, M. R., Zhong, H., Ruck, R. T., Shevlin, M. & Chirik, P. J. Cobalt-catalyzed asymmetric hydrogenation of enamides enabled by single-electron reduction. Science 360, 888–893 (2018).

    CAS  Article  Google Scholar 

  18. 18.

    Knowles, W. S. Asymmetric hydrogenations (Nobel lecture). Angew. Chem. Int. Ed. 41, 1998–2007 (2002).

    CAS  Article  Google Scholar 

  19. 19.

    Mukherjee, D., Ellern, A. & Sadow, A. D. Conversion of a zinc disilazide to a zinc hydride mediated by LiCl. J. Am. Chem. Soc. 132, 7582–7583 (2010).

    CAS  Article  Google Scholar 

  20. 20.

    Kläui, W., Schilde, U. & Schmidt, M. Fluoro[η3-hydrotris(3-R-5-methylpyrazol-1-yl)borato]zinc(ii): The first TpZnF complexes, convenient precursors to zinc hydride complexes. Inorg. Chem. 36, 1598–1601 (1997).

  21. 21.

    Sattler, W. & Parkin, G. Zinc catalysts for on-demand hydrogen generation and carbon dioxide functionalization. J. Am. Chem. Soc. 134, 17462–17465 (2012).

    CAS  Article  Google Scholar 

  22. 22.

    Ilic, S., Alherz, A., Musgrave, C. B. & Glusac, K. D. Thermodynamic and kinetic hydricities of metal-free hydrides. Chem. Soc. Rev. 47, 2809–2836 (2018).

    CAS  Article  Google Scholar 

  23. 23.

    Sun, Z. et al. Catalytic asymmetric reduction of difficult-to-reduce ketones: Triple-code saturation mutagenesis of an alcohol dehydrogenase. ACS Catal. 6, 1598–1605 (2016).

    CAS  Article  Google Scholar 

  24. 24.

    Paul, C. E., Lavandera, I., Gotor-Fernández, V., Kroutil, W. & Gotor, V. Escherichia coli/ADH-A: An all-inclusive catalyst for the selective biooxidation and deracemisation of secondary alcohols. ChemCatChem 5, 3875–3881 (2013).

    CAS  Article  Google Scholar 

  25. 25.

    Kitamura, M. et al. Homogeneous asymmetric hydrogenation of functionalized ketones. J. Am. Chem. Soc. 110, 629–631 (1988).

    CAS  Article  Google Scholar 

  26. 26.

    Li, W., Lu, B., Xie, X. & Zhang, Z. Ru-catalyzed chemo- and enantioselective hydrogenation of β-diketones assisted by the neighboring heteroatoms. Org. Lett. 21, 5509–5513 (2019).

    CAS  Article  Google Scholar 

  27. 27.

    Gajewy, J., Gawronski, J. & Kwit, M. Mechanism and enantioselectivity of [zinc(diamine)(diol)]-catalyzed asymmetric hydrosilylation of ketones: DFT, NMR and ECD studies. Eur. J. Org. Chem. 2013, 307–318 (2013).

    CAS  Article  Google Scholar 

  28. 28.

    Mukherjee, D., Thompson, R. R., Ellern, A. & Sadow, A. D. Coordinatively saturated tris(oxazolinyl)borato zinc hydride-catalyzed cross dehydrocoupling of silanes and alcohols. ACS Catal. 1, 698–702 (2011).

    CAS  Article  Google Scholar 

  29. 29.

    Rauch, M., Rong, Y., Sattler, W. & Parkin, G. Synthesis of a terminal zinc hydride compound, [TpBut,Me]ZnH, from a hydroxide derivative, [TpBut,Me]ZnOH: Interconversions with the fluoride complex, [TpBut,Me]ZnF. Polyhedron 103, 135–140 (2016).

    CAS  Article  Google Scholar 

  30. 30.

    Bergquist, C., Koutcher, L., Vaught, A. L. & Parkin, G. Reactivity of the B−H bond in tris(pyrazolyl)hydroborato zinc complexes: Unexpected example of zinc hydride formation in a protic solvent and its relevance towards hydrogen transfer to NAD+ mimics by tris(pyrazolyl)hydroborato zinc complexes in alcoholic media. Inorg. Chem. 41, 625–627 (2002).

    CAS  Article  Google Scholar 

  31. 31.

    Bergquist, C. & Parkin, G. Modeling the catalytic cycle of liver alcohol dehydrogenase: Synthesis and structural characterization of a four-coordinate zinc ethoxide complex and determination of relative Zn−OR versus Zn−OH bond energies. Inorg. Chem. 38, 422–423 (1999).

    CAS  Article  Google Scholar 

  32. 32.

    Senn, H. M. & Thiel, W. QM/MM methods for biomolecular systems. Angew. Chem. Int. Ed. 48, 1198–1229 (2009).

    CAS  Article  Google Scholar 

  33. 33.

    Field, M. J., Bash, P. A. & Karplus, M. A combined quantum mechanical and molecular mechanical potential for molecular dynamics simulations. J. Comput. Chem. 11, 700–733 (1990).

    CAS  Article  Google Scholar 

  34. 34.

    Lewis, R. D. et al. Catalytic iron-carbene intermediate revealed in a cytochrome c carbene transferase. Proc. Natl Acad. Sci. USA 115, 7308–7313 (2018).

    CAS  Article  Google Scholar 

  35. 35.

    Baker Dockrey, S. A., Lukowski, A. L., Becker, M. R. & Narayan, A. R. H. Biocatalytic site- and enantioselective oxidative dearomatization of phenols. Nat. Chem. 10, 119–125 (2018).

    CAS  Article  Google Scholar 

  36. 36.

    Howard, E. I. et al. Ultrahigh resolution drug design I: Details of interactions in human aldose reductase–inhibitor complex at 0.66 Å. Proteins 55, 792–804 (2004).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

The work on enantioselective reductions was supported by the NIH (grant no. R37 GM130387) and the studies pertaining to the intermediacy of the metal hydride were supported by the Director, Office of Science, of the US Department of Energy under Contract No. DEAC02-05CH11231. We thank the Berkeley DNA Sequencing Facility for plasmid sequencing. We thank the College of Chemistry’s Molecular Graphics and Computing Facility for resources provided and K. Durkin for her assistance. The COC-MGCF is supported in part by the NIH (grant no. S10OD023532). P.J. acknowledges support from the Miller Institute for Basic Research in Science at the University of California Berkeley for a postdoctoral fellowship.

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Contributions

P.J. and J.F.H. conceived and designed the project. P.J. performed initial discovery and optimization of reaction conditions, mechanistic studies and all computational experiments. P.J. and J.-Y.P. performed the study of substrate scope. Y.G. and P.J. screened the activity of different mutants. P.J., D.S.C. and J.F.H analysed the data. P.J. and J.F.H. wrote the manuscript with input from all other authors.

Corresponding author

Correspondence to John F. Hartwig.

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The authors declare no competing interests.

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Peer review information Nature Chemistry thanks the, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary information includes methods for protein expression and purification, DNA and protein sequences, protocols for catalytic reactions (including those with purified protein and with the whole cells), procedure for mechanistic experiments, preparation of racemic standards, computational study, products and characterizations and NMR spectra, Supplementary Figs. 1–33 and Table 1.

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Ji, P., Park, J., Gu, Y. et al. Abiotic reduction of ketones with silanes catalysed by carbonic anhydrase through an enzymatic zinc hydride. Nat. Chem. 13, 312–318 (2021). https://doi.org/10.1038/s41557-020-00633-7

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