The symmetric designer protein Pizza as a scaffold for metal coordination.

Symmetric proteins are currently of interest as they allow creation of larger assemblies and facilitate the incorporation of metal ions in the larger complexes. Recently this was demonstrated by the biomineralization of the cadmium-chloride nanocrystal via the Pizza designer protein. However, the mechanism behind this formation remained unclear.

Development and applications of artificial symmetrical proteins.

Since the determination of the first molecular models of proteins there has been interest in creating proteins artificially, but such methods have only become widely successful in the last decade. Gradual improvements over a long period of time have now yielded numerous examples of non-natural proteins, many of which are built from repeated elements. In this review we discuss the design of such symmetrical proteins and their various applications in chemistry and medicine.

Molecular assemblies built with the artificial protein Pizza.

Recently an artificial protein named Pizza6 was reported, which possesses six identical tandem repeats and adopts a monomeric -propeller fold with sixfold structural symmetry. Pizza2, a truncated form that consists of a double tandem repeat, self-assembles into a trimer reconstructing the same propeller architecture as Pizza6. The ability of pizza proteins to self-assemble to form complete propellers makes them interesting building blocks to engineer larger symmetrical protein complexes such as symmetric nanoparticles.