In the Protein Engineering lab of TU/e professor Maarten Merkx directed evolution is a familiar method. New proteins for use as medicines, or as a catalyst for a chemical process, these you can try to design sitting at your computer, he explains, but it is very difficult. “The alternative is the method for which the Nobel Prize has now been awarded: directed evolution. Here, you start with a set of billions of different proteins, and you devise a smart way of retrieving the variant that best satisfies your criteria. Then you make a number of variants of that particular one, from which you again make a selection. And so you continue until the selected protein has the desired characteristics. Comparable to how natural evolution works over successive generations, but much faster.”

With these awards, the Nobel Committee is neatly rewarding both tracks within the field of directed evolution, according to Merkx. He personally uses the method developed by Smith and Winter, ‘phage display’, whereby bacteriophages (viruses whose hosts are bacteria) are used to find new antibodies – proteins that bind to elements foreign to the body such as bacteria and viruses, and which in so doing play an essential role in our immune system. “Therapeutic antibodies made with the help of ‘phage display’ are currently the most important class of new medicines. So this technology is already tried and tested and therefore, in my opinion, the Nobel Prize is certainly justified.”

The work of winner Frances Arnold focuses on the directed evolution of another class of proteins: enzymes. These molecules act as a catalyst in the conversion of chemicals. Such enzymes are already used in the environmentally friendly production of raw materials for medicines and renewable fuels.