Beamlines | I19 Case Study

Molecule reorganises itself for new functions

The discovery of a synthetic molecule made up of 60 simple components able to reorganise themselves to produce new functions will lead to better understanding of Nature’s processes.

The incredibly complex structure of the pentagonal prismatic molecule was discovered when researchers working at The University of Queensland, The University of Cambridge, and Randolph-Macon College in the USA, formed the structure by transforming a tetrahedral molecule into a second structure - a barrel-like pentagonal prism. They used Diamond Light Source to look at the atomic structure of their molecule and confirm its geometry.
 
Understanding the structure of synthetic molecules which are able to reorganise themselves is important as it helps scientists to understand natural processes in molecules such as viruses which are assembled from small parts. The finding was published in the journal Nature Chemistry.
 
 
In synthesising the molecule, the researchers used a technique known as “self-assembly”, which regulates many of the complex and functional components in biological systems like DNA, to prepare a molecular tetrahedron from twenty-two simple building blocks.
 
The building blocks employed were then chemically programmed to spontaneously react together to form the desired molecule.

Upon addition of a chemical template, the tetrahedral molecule was reconfigured into a new barrel-like structure composed of an impressive 60 smaller molecules. The team then used an X-ray beam on the Diamond synchrotron’s Small Molecule Diffraction beamline, I19, to determine the structure. The intense source of the synchrotron was required because of the shear size of the molecule. It crystallises with more than 1000 distinct atoms and an enormous unit cell. The shortest side of the unit cell is more than 70 Å long and with a cell volume of more than 450,000 Å3 the size of the structure is close to that of proteins. It is one of the largest structures ever solved on I19.

Anion-induced reconstitution of a self-assembling system to express a chloride-binding Co10L15 pentagonal prism
Imogen A. Riddell, Maarten M. J. Smulders, Jack K. Clegg, Yana R. Hristova, Boris Breiner, John D. Thoburn & Jonathan R. Nitschke
Nature Chemistry 4, 751–756 (2012)
doi:10.1038/nchem.1407