Months after the death of the dictator Francisco Franco, a 19-year-old American girl landed in Madrid to do a summer internship at the Westinghouse company, manufacturer of the first nuclear reactors in Spain. The young woman, an engineering student, settled in a shared flat on Ibiza Street, next to the Retiro Park. “I spent a wonderful summer in Madrid in 1976. I was young, the new democracy was young … It was a constant party,” he recalls now Frances Arnold, born 64 years ago in Pittsburgh. In her hometown she had already been a pizza maker, a receptionist, a waitress at a jazz club and even a taxi driver. In Madrid, with a dictionary in hand, he began to devour the books of the Argentine writer Jorge Luis Borges. And according to Arnold, Borgian literature helped him win the Nobel Prize in Chemistry in 2018.
The American scientist explains that she is dedicated to raising proteins like other dogs breed: with directed evolution. If animals as different as poodles, greyhounds and Dalmatians have been obtained from wild wolves, Arnold causes mutations in the proteins and selects the ones that interest him the most. The result is new molecules that, according to highlights your Nobel token, “Solve the chemical problems of humanity”, such as the manufacture of drugs without pollution or the production of renewable energy. Arnold, a chemical engineer from the California Institute of Technology, has returned to Spain to participate this Thursday in the award ceremony of the Princess of Girona Foundation Awards, in Barcelona.
Question. What was that young Frances Arnold who lived in Madrid in 1976 like?
Answer. Curious I wanted to learn everything: Spanish, Spanish culture, Spanish gastronomy, tapas, music, literature. I read all the time. It absorbed a lot of information.
P. You had worked as a taxi driver in Pittsburgh before.
R. Yes, she was one of the few female taxi drivers. They were huge yellow cabs and the streets of Pittsburgh are very narrow. I learned to orient myself and maneuver in difficult circumstances.
P. I was just 18 years old, it would be tough.
R. I didn’t even think about it, I was capable of doing anything, like all 18-year-olds. Only later do we learn our limitations.
“At 18 you are capable of doing anything, only afterwards do we learn our limitations”
P. Having been a taxi driver is not the usual résumé at the Nobel Prize winners. Do you know if there are more former taxi drivers who have won the Nobel?
R. I’m not sure I’m the only one, because most of us had to work our way to college. It was not uncommon for young people to work. In a pizzeria they paid you 75 cents an hour, but as a taxi driver you made two or three dollars an hour. It was so much easier to earn money. At Princeton I also worked as a taxi driver for two years.
P. You also worked cleaning the house of the philosopher of science Thomas Kuhn.
R. Yes, Thomas Kuhn had an embroidery on the wall that said, “Bless this paradigm.” He was never at home, because I was going to clean during the day.
P. He couldn’t learn philosophy from Thomas Kuhn, then.
R. No, I just learned that he smoked too many pipes. [Risas]
P. You counted in the Nobel speech that Jorge Luis Borges had a great influence on his work in chemistry. How?
R. One of Borges’s tales, The library of Babel [sobre una biblioteca que parece tener todos los libros posibles], is the best description I know of a universe of possibilities. If you pick letters of the alphabet at random and put them together in a book, what you usually get is gibberish. The same goes for DNA, the book of life. This frustrated the librarians of The library of Babel, because they never found a certain book. If you have a library with all possible books, you cannot find anything that makes sense. Instead, if we think of all the possible books in life, you can find the ones that have meaning simply by scratching the sole of your shoe. Life’s library of books is as big as Jorge Luis Borges’s, but books with meaning are everywhere, thanks to evolution. Evolution has already reviewed all the possibilities and found the ones that encode life, so we can find these beautiful books anywhere. Jorge Luis Borges described the dimension of possibilities and [el naturalista inglés Charles] Darwin discovered how to navigate that library.
P. The story of The library of Babel is required reading in your molecular engineering classes at the California Institute of Technology.
R. Yes, the students love it. If you read The library of Babel you understand what the word big means.
P. As a young man he was not interested in chemistry at all and has ended up winning the Nobel Prize in Chemistry. Do you have a message for young people who are not attracted to chemistry?
R. Life is long, you can have many different lives. You can learn many different things, you never know when they will serve you well, so learn as much as you can and combine your knowledge in new ways. Adapt, be flexible and learn permanently.
P. What applications of directed evolution can we see in everyday life?
R. Almost everyone uses the products of directed evolution. For example, when you wash clothes there are enzymes [proteínas que favorecen una reacción química] in detergent and all are made by directed evolution, optimized to work in a washing machine. And there are tons of other examples. Many drugs are produced by enzymes made with directed evolution. And these enzymes are also used to diagnose and treat diseases.
P. You never patented the technology to achieve directed evolution. Why?
R. I wanted the world to use it. Nor did I believe I had the right to be the owner of evolution. You can patent very specific methods, but you can’t patent a general idea. And I felt that the general idea was so obvious and important that the world should take advantage of it.
“I did not patent my technology because I did not believe I had the right to be the owner of evolution”
P. He regrets? Now you could be swimming in money.
R. I do not regret. Nor am I interested in swimming in money, I am much more interested in the world using this powerful process.
P. You proclaimed in his Nobel speech that the code of life is like a symphony. Do you think there is a Beethoven, a god, who wrote that code?
R. I think evolution wrote that code.
P. How do you envision the future with directed evolution?
R. My dream is to stop using dirty human chemistry for our daily needs. What we wear, where we sit, what we burn in cars … all are products of human chemistry. If we could make a transition to a clean, efficient, circular, sustainable biological chemistry … Encode in bacteria the ability to do whatever you want. I dream of stopping using polluting procedures and adopting really clean alternatives.
P. Do you think chemistry is dirty nowadays?
P. The chemical industry tries to give a clean image.
R. It is much cleaner than before, but much of it is still inefficient and its by-products continue to pollute the planet. Now it is much better than before, because manufacturers have to pay to pollute. And when they have to pay the price of pollution, they clean up. But there is still a lot of room for improvement.
“Evolution wrote the code of life”
P. What are you working on now?
R. Evolution, for about 4 billion years, has done everything in the biological world, but this is the past. Chemists can now explore completely new things using evolution. I am not talking about optimization, which is what we did in the past: take something that already exists and improve it, as with laundry detergent. I’m talking about doing something completely new: a new chemistry, with chemical bonds that nature has never made. Carbon and silicon bonds, for example. Here [dice señalando a su alrededor en la azotea de un hotel de Barcelona] There will be 50 products with carbon and silicon bonds, all made with dirty human chemistry. If we could code for that in DNA, we could achieve the same with clean chemistry, but no one has found an enzyme in nature that makes that carbon and silicon bond. So I have made it thanks to evolution.
P. Last year you had to retract a study published in the magazine Science because their results were not reproducible. You tweeted: “It hurts to admit it, but it is important to do so. I apologize to everyone. I was pretty busy when we sent the study and I didn’t do my job well. ” What happened to that study? Did the first signer make up the data?
R. I do not want to talk about that. I made it very clear that I take the blame. It is my responsibility.
P. His apologies were applauded. Why do you think there was such a reaction?
R. The first reaction was: “Take away the Nobel Prize.” That lasted about six hours, because afterwards everyone said, “Wait, it’s great to admit a mistake and correct it.” I did not want students to waste time trying to reproduce what I had published. It was not fair. It was much easier to admit it publicly so that no one was wasting time. People forgive you if you are honest, because they know that people make mistakes.