The 2018 Nobel Prize in Chemistry has gone to three scientists that used the principle of evolution to produce new chemical compounds. Half of the prize goes to Professor Frances Arnold who conducted the first directed evolution of enzymes, proteins that speed up chemical reactions. The second half goes to Professor George Smith and Professor Gregory Winter for their work on using viruses to evolve new proteins and antibodies.
The work conducted by the winners has had life-changing applications. Their techniques have been used in various industries, have led to greener methods of production, and have helped us develop new cancer-fighting drugs. As the Nobel committee has stated, this work has hugely benefitted humankind.
In 1993, Professor Arnold pioneered methods of directed evolution, namely genetic change and selection, to produce important enzymes. Enzymes are tiny proteins that act as natural catalysts, speeding up natural reactions. Living organisms are constantly using them in a variety of important bodily processes, such as digestion.
Enzymes are produced by following instructions on DNA, so by adding mutations, it is possible to create very useful ones, as well as some rubbish ones. By employing bacteria as a production line, Arnold was able to mutate different enzymes. She then selected the most efficient at catalyzing a particular chemical reaction. This approach has found application in pharmaceuticals, biofuels, and many other areas.
In contrast, Smith and Winter's work is based on bacteriophages, the viruses that infect bacteria. Professor Smith, like Frances Arnold, altered bacteria to get proteins but in a different way. Smith altered bacterial DNA by inserting a specific protein into the genetic code of a bacteriophage. These viruses use the apparatus inside a bacterium to reproduce, so adding the gene meant that this protein was present on the surface of the virus. The next step just requires a specific antibody to go and fish out the protein. This is a very useful way to evolve new proteins.
Professor Winter's work focused on the creation of new antibodies. The approach, known as phage display, has similarities to Smith’s but differs from it in a few key ways. The phages have antibodies growing on them and these are selected based on how well they interact with certain compounds. There are several iterations of this approach to tune how well the antibodies target the particular compound. This method was used to create antibodies that can neutralize toxins, cure cancer that has spread, and counteract autoimmune diseases. The first new drug that uses this method was approved in 2002 and is used to treat psoriasis, rheumatoid arthritis, and inflammatory bowel disease.
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