Biomineralization of a Cadmium Chloride Nanocrystal by a Designed Symmetrical Protein. Issue 34 (1st July 2015)

• Record Type: Journal Article
• Authors: Voet, Arnout R. D.; Noguchi, Hiroki; Addy, Christine; Zhang, Kam Y. J.; Tame, Jeremy R. H.
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 34(2015)
• Page Start: 9857
• Page End: 9860
• Publication Date: 2015-07-01
• Subjects: biomineralization -- 2D crystals -- metalloproteins -- nanomaterials -- oligomers; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201503575
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: We have engineered a metal‐binding site into the novel artificial β‐propeller protein Pizza. This new Pizza variant carries two nearly identical domains per polypeptide chain, and forms a trimer with three‐fold symmetry. The designed single metal ion binding site lies on the symmetry axis, bonding the trimer together. Two copies of the trimer associate in the presence of cadmium chloride in solution, and very high‐resolution X‐ray crystallographic analysis reveals a nanocrystal of cadmium chloride, sandwiched between two trimers of the protein. This nanocrystal, containing seven cadmium ions lying in a plane and twelve interspersed chloride ions, is the smallest reported to date. Our results indicate the feasibility of using rationally designed symmetrical proteins to biomineralize nanocrystals with useful properties. Abstract : Protein design : A novel artificial protein with pseudo‐six‐fold symmetry creates a nanocrystal of cadmium chloride, sandwiched between two copies of the protein (see picture). X‐ray structural evidence for the formation of the nanocrystal inside the protein is presented.