Proteins with Professor Juliet Gerrard
There are thousands of different proteins in every cell, and they do not work alone. The cell is like a giant, moving, three-dimensional jigsaw puzzle, and the way all these pieces interact dictates the way they carry out biological functions, like carrying oxygen, or replicating themselves when we grow. Proteins do not act on their own; they need to interact with other biomolecules, often more than one; they are promiscuous! Scientists are now beginning to understand how these biomolecular interactions take place, and how all these proteins choose their partners, which is leading to some exciting discoveries. The Nobel Prizes in both Medicine and Chemistry this year were awarded to scientists who uncovered important details about biomolecular interactions. In Medicine, three scientists (Elizabeth H. Blackburn, Carol W. Greider and Jack W. Szostak) were awarded the prize for uncovering how a protein called telomerase interacts with our chromosomes to ensure they are accurately replicated. This knowledge was not only of fundamental interest, but has also helped provide some new leads in the search for anti-cancer agents. In Chemistry, the Nobel Prize went to three scientists (Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath) for elucidating the structure of the ribosome, a biomolecular machine that has numerous interacting components that enable it to crack the genetic code and turn the information carried in our chromosomes into functioning proteins to carry out the work of the cell. Again, the pursuit of knowledge led to some applications that are useful to society. It turns out that bacteria and humans carry out this process with slightly different machinery, and that antibiotics can be designed to switch off the bacterial process and leave the human one untouched. These discoveries were made in some of the great Universities of the world. What can we achieve here in Canterbury, New Zealand? Here we will highlight several examples of research on the interactions of proteins, all carried out locally. The four examples in the title describe projects carried out by researchers at the Biomolecular Interaction Centre (BIC), a multi-disciplinary endeavour based at the University of Canterbury and involving researchers from Plant & Food Research, ESR, AgResearch, Lincoln University and Otago University’s Christchurch School of Medicine. Researchers at the BIC, led by Conan Fee, Juliet Gerrard, Emily Parker and William Swallow, share a common interest in understanding how proteins interact with each other and how we can harness this knowledge in cells and in a range of applications for biotechnology to benefit society.
The way in which proteins interact with one another is critical to the roles they carry out in cells. As described above for the ribosome, the way proteins snuggle together in bacterial cells is subtly different to the way they interact in our own cells. One thing that bacteria do, that human cells can’t do, is to make their own amino acids. Taking advantage of this knowledge allows us to design new drugs that stop bacterial cells doing this, and kill them, while leaving human cells untouched. Researchers in the BIC, in collaboration with the Maurice Wilkins Centre and researchers from the University of Melbourne, are using this approach to find new ways to combat diseases such as tuberculosis and meningitis.
Proteins are incredibly sophisticated molecular machines that carry out a huge number of different functions in the cell. We now understand them well enough to start using them for our own ends outside cells. Another project in the BIC uses waste materials from New Zealand abattoirs to manufacture nanotubes from protein. These protein nanotubes can be used for a wide range of applications, for example as nanowires (in collaboration with the MacDiarmid Institute), biosensors, or nanoscaffolds for enzymes with useful functions.
Some lateral thinking has enable BIC researchers to put ideas from both the above projects to good use in defence applications. Antibiotic strategies are readily applied to combat anthrax, a major bioterrorism issue. Use of protein nanotubes as a nanoscaffold is being applied to chemical detoxification too, with an enzyme that can specifically destroy deadly molecules like Sarin. This work may also have spill-over benefit in bioremediation of the environment.
Big fluffy croissants:
As well as all the high-tech applications opened up by an understanding of protein interactions, they remain an important component of our diet. Not only do proteins give us nutritional benefit, they are also responsible for the texture and quality of many foods. Work with Plant & Food Research has included an exploration of how to manipulate the way that proteins interact within a food matrix, to improve their properties. This has led to improvements in the quality of many foods, including the big fluffy croissants in the title!These examples are just the tip of the iceberg. Proteins are extremely versatile molecules and our contemporary understanding of how they interact with each other opens up an increasing number of applications of huge potential benefit to society, in New Zealand and beyond.