Press Releases

Success in taking a protein alive in an artificial capsule-A protein was encapsulated within a self-assembled capsular molecule- : Professor Makoto Fujita & Lecturer Sota Sato, Department of Applied ChemistryJapanese Page

October 3, 2012

    The research group of Professor Makoto Fujita in Department of Applied Chemistry, School of Engineering, The University of Tokyo succeeded in encapsulation of a whole protein within a synthesized capsular molecule with the diameter of seven nanometers.

    In nature, biomolecules like proteins or DNA are encapsulated within huge capsular materials like virus cages, where the structures or activities of the biomolecules are controlled or the biomolecules are stored until they are used. In an artificial chemical phenomena, small organic molecules are encapsulated within hollow capsular molecules, called “host molecules”, where the structures or activities of the encapsulated guest molecules are also controlled. However, huge biomolecules like proteins have never been encapsulated because the sizes of the artificial capsular molecules with precise structures are limited.

    Here, the research group synthesized huge metal-organic complexes (artificial capsules) utilizing self-assembly process, where metal ions and organic compounds are just mixed in a flask and the coordination bonds between the starting materials automatically construct the ordered precise structures. A whole protein was successfully encapsulated in the capsular complex.

    A wide variety of applications in the fields of industry, drug discovery, and so on are expected, because the encapsulation of proteins could be useful for structural analysis or functional improvement of the trapped proteins.


The structure of the self-assembled, huge capsular molecule encapsulating a whole protein from building units of organic molecules and palladium ions. The product has a single, precise structure,  where sugar chains make an internal hydrophilic interface to hold the protein stably.