Upon 70º C thermal exposure, MOF-encapsulated BSA remains folded while native BSA unfolds. From R. Murty et al., J. Am. Chem. Soc. 2023, 145 © 2023 The Authors. Published by American Chemical Society

It has been hypothesized that the confinement of guest molecules within a rigid metal−organic framework (MOF) scaffold results in a heightened stability of the guests, but no direct evidence of this mechanism had, until now, been observed. A research team employed a novel analytical method using small-angle x-ray scattering (SAXS) at the Anomalous Small and Wide Angle X-ray Scattering facility of ChemMatCARS at the Advanced Photon Source, Argonne National Laboratory, to solve the structure of bovine serum albumin encapsulated in two zeolitic imidazolate frameworks (ZIF-67 and ZIF-8).

This study indicates that encapsulating biomacromolecules within MOFs can confer thermostability to entrapped guests and that protein thermostability by MOF encapsulation may be due to the physical entrapment of the protein that prevents conformational change.

These results support the potentiality of future in situ SAXS analyses of proteins or other compounds encapsulated in MOFs (as well as other host matrices) to advance fundamental research and translation into applications involving protein encapsulation and stabilization.

The study also introduced a new method for calculating the SAXS spectra associated with proteins encapsulated in MOF host matrices measured in situ.

Rohan Murty1, Mrinal K. Bera2, Ian M. Walton1, Christina Whetzel1, Mark R. Prausnitz1*, and Krista S. Walton1**, “Interrogating Encapsulated Protein Structure within Metal−Organic Frameworks at Elevated Temperature,” J. Am. Chem. Soc. 2023, 145, 7323−7330. DOI: 10.1021/jacs.2c13525 1Georgia Institute of Technology, 2The University of Chicago Correspondence: *prausnitz@gatech.edu

For information about anomalous small-angle x-ray scattering at NSF’s ChemMatCARS:

Mrinal Bera
(630) 252-0472