Hierarchical self-assembly of a supramolecular protein-metal cage encapsulating a polyoxometalate guest

DOI: 10.1021/acs.cgd.1c01138

Authors: Laurens Vandebroek (KU Leuven) , Hiroki Noguchi (KU Leuven) , Alexander Anyushin (KU Leuven) , Luc Van Meervelt (KU Leuven) , Arnout R. D. Voet (KU Leuven) , Tatjana N. Parac-Vogt (KU Leuven)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Crystal Growth & Design , VOL 22 , PAGES 1515 - 1520

State: Published (Approved)
Published: March 2022

Abstract: Hierarchical self-assembly of hybrid bioinorganic structures is a challenging task which requires specific and tailored interactions. Here we report a supramolecular assembly formed between the six-bladed symmetrical designer protein Pizza6-S (Pizza6) and the {K3Cu3(NO3)[A-α-PW9O34]2} (Cu3) polyoxometalate (POM). The crystal structure (1.8 Å resolution) revealed that the Cu3 dissociated and reassembled with the protein to form a novel POM-protein cage. In this hybrid assembly, six CuII ions link two Pizza6 molecules in a controlled way by binding to the six symmetrically equivalent histidine side chains. Such coordination results in the formation of a “bioinorganic cage” in which a lacunary [A-α-PW9O34]9– (PW9) anion is tightly encapsulated via coordination to CuII ions and hydrogen bonding with protein side chains. Further spectroscopic characterization of the Pizza6/Cu3 solution suggests that dissociation of Cu3 is facilitated by the synergetic effect of six histidine residues which have high affinity toward Cu(II) ions, resulting in the formation of the hierarchical supramolecular assembly.

Journal Keywords: Encapsulation; Ligands; Ions; Anions; Imidazoles

Subject Areas: Biology and Bio-materials


Instruments: I03-Macromolecular Crystallography

Added On: 27/04/2022 11:38

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)