Protein-Structure-Directed Metal-Organic Zeolite-like Networks as Biomacromolecule Carriers

Abstract

Fabrication of zeolite-like metal-organic frameworks (ZMOFs) for advanced applications, such as enzyme immobilization, is of great interest but is a great synthetic challenge. Herein, we have developed a new strategy using proteins as structure-directed agents to direct the formation of new ZMOFs that can act as versatile platforms for the in situ encapsulation of proteins under ambient conditions. Notably, protein incorporation directs the formation of a ZMOF with a sodalite (sod) topology instead of a non-porous diamondoid (dia) topology under analogous synthetic conditions. Histidines in proteins play a crucial role in the observed templating effect. Modulating histidine content thereby influenced the resultant MOF product (from dia to dia + sod mixture and, ultimately, to sod MOF). Moreover, the resulting ZMOF-incorporated proteins preserved their activity even after exposure to high temperatures and organic solvents, demonstrating their potential for biocatalysis and biopharmaceutical applications.

Keywords: enzyme immobilization; metal-organic frameworks; protein structure; self-assembly; template synthesis; zeolite analogues.