Dr. Eyal Golub
University of California, San Diego
Department of Chemistry and Biochemistry
Biopolymers are among the largest groups of materials in nature that exhibit diversified surface chemistry that when coupled with a multitude of folds and assembly motifs give rise to a large variety of functionalities. Proteins, nature’s favorite building block, exhibit compositional and functional abundance that is accompanied by complicated self-assembly properties that are very challenging to design. Although various methods for controlled protein self-assembly were developed, they are still lacking in efficient design of high symmetry axes (C>2) and dynamic constructs that are essential bottlenecks in material design. As such, an inorganic approach was adopted whereby interfaces were selectively formed by tailoring the affinity of a specific metal for a desired interface using the Pearson Hard-Soft Acid-Base classification combined with the inherent symmetry imposed by a specific set of ligands. To that end native ligands were used to coordinate Zn(II) ions and stabilize C2 symmetry nodes, while bioinspired hydroxamic acid was used as a strategic handle to coordinate hard Fe(III) ions, leading to tris-hydroxamate-Fe(III) complexes at the C3 nodes. This strategy was successfully implemented for the formation of two types of nanometer-size protein cages as well as in the design of a supramolecular protein switch that traverses between various constructs. Thus, such an approach enables the design of robust and well-defined materials that their unique assembly motifs imbues them with multi-stimuli assembly mechanisms.