Protein-Directed Self-Assembly of a Fullerene Crystal

Kook-Han Kim, Sungkyunkwan University
Dong-Kyun Ko, New Jersey Institute of Technology
Yong-Tae Kim, Sungkyunkwan University
Nam Hyeong Kim, Sungkyunkwan University
Jaydeep Paul, National Institute of Science Education and Research
Shao-Qing Zhang, University of California, San Francisco
Christopher B. Murray, University of Pennsylvania
Rudresh Acharya, National Institute of Science Education and Research
William F. DeGrado, University of California, San Francisco
Yong Ho Kim, Sungkyunkwan University
Gevorg Grigoryan, Dartmouth College


Learning to engineer self-assembly would enable the precise organization of molecules by design to create matter with tailored properties. Here we demonstrate that proteins can direct the self-assembly of buckminsterfullerene (C60) into ordered superstructures. A previously engineered tetrameric helical bundle binds C60 in solution, rendering it water soluble. Two tetramers associate with one C60, promoting further organization revealed in a 1.67-Å crystal structure. Fullerene groups occupy periodic lattice sites, sandwiched between two Tyr residues from adjacent tetramers. Strikingly, the assembly exhibits high charge conductance, whereas both the protein-alone crystal and amorphous C60 are electrically insulating. The affinity of C60 for its crystal-binding site is estimated to be in the nanomolar range, with lattices of known protein crystals geometrically compatible with incorporating the motif. Taken together, these findings suggest a new means of organizing fullerene molecules into a rich variety of lattices to generate new properties by design.