She shared this year’s chemistry Nobel — worth close to $1 million — with George P. Smith, 77, and Gregory P. Winter, 67. Dr. Arnold received half of the prize, and Dr. Smith and Dr. Winter split the other half.
Dr. Arnold won for her work conducting the directed evolution of enzymes, proteins that catalyze chemical reactions. She first pioneered the bioengineering method, which works similar to the way dog breeders mate specific dogs to bring out desired traits, in the early 1990s, and has refined it since then.
Her enzymes have been used to make biofuels, medicines and laundry detergent, among other things. In many processes, they have taken the place of toxic chemicals.
Dr. Smith was honored for developing a method, known as phage display, in which a virus that infects bacteria can be used to evolve new proteins. Dr. Winter won for evolving antibodies through phage display to combat autoimmune diseases and in some cases, cure metastatic cancer.
“I think of what I do as copying nature’s design process,” Dr. Arnold said in an interview with NobelPrize.org. “All this tremendous beauty and complexity of the biological world all comes about to this one simple beautiful design algorithm.”
In the 1980s, Dr. Arnold tried to rebuild enzymes, but because they are very complex molecules built from different amino acids that can be infinitely combined, she found it difficult to remodel the enzymes’ genes in order to give them new properties.
In the 1990s, she abandoned what she called her “somewhat arrogant approach” of trying to create modified enzymes through her logic and knowledge, and examined nature’s way of doing things. She looked into evolution.
Dr. Arnold with President Barack Obama at an award ceremony for the National Medal of Technology and Innovation in 2013. Dr. Arnold was awarded the prize in 2011.CreditBrendan Hoffman/Getty Images