Moons J, Loosen A, Simms C, de Azambuja F, Parac-Vogt TN. Heterogeneous nanozymatic activity of Hf oxo-clusters embedded in a metal-organic framework towards peptide bond hydrolysis.
NANOSCALE 2021;
13:12298-12305. [PMID:
34254101 DOI:
10.1039/d1nr01790j]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Materials with enzyme-like activities and proteolytic potential are emerging as a robust and effective alternative to natural enzymes. Herein, a Hf6O8-based NU-1000 metal organic framework (Hf-MOF) is shown to act as a heterogeneous catalyst for the hydrolysis of peptide bonds under mild conditions. In the presence of Hf-MOF, a glycylglycine model dipeptide was hydrolysed with a rate constant of kobs = 8.33 × 10-7 s-1 (half-life (t1/2) of 231 h) at 60 °C and pD 7.4, which is significantly faster than the uncatalyzed reaction. Other Gly-X peptides (X = Ser, Asp, Ile, Ala, and His) were also smoothly hydrolysed under the same conditions with similar rates, except for the faster reactions observed for Gly-His and Gly-Ser. Moreover, the Hf6O8-based NU-1000 MOF also exhibits a high selectivity in the cleavage of a protein substrate, hen egg white lysozyme (HEWL). Our results suggest that embedding Hf6O8 oxo-clusters is an efficient strategy to conserve the hydrolytic activity while smoothing the strong substrate adsorption previously observed for a discrete Hf oxo-cluster that hindered further development of its proteolytic potential. Furthermore, comparison with isostructural Zr-NU-1000 shows that although the Hf variant afforded the same cleavage pattern towards HEWL but slightly slower reaction rates, it exhibited a larger stability window and a better recyclability profile. The results suggest that these differences originate from the intrinsic differences between HfIV and ZrIV centers, and from the lower surface area of Hf-NU-1000 in comparison to Zr-NU-1000.
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