Nobel Prize in Chemistry Goes to a Woman for the Fifth Time in History

Frances H. Arnold in 2016. She was awarded the Nobel Prize in Chemistry for her work conducting the directed evolution of enzymes.CreditCreditHeikki Saukkomaa/Agence France-Presse — Getty Images

Since 1901, when the Nobel Prize in Chemistry was first awarded, 177 people have captured the honor. On Wednesday, Frances H. Arnold became only the fifth woman to be awarded the prize.

Dr. Arnold, 62, an American professor of chemical engineering, bioengineering and biochemistry at the California Institute of Technology in Pasadena, earned the award for her work with the directed evolution of enzymes.

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.

“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.

[On Tuesday, a woman was awarded the Nobel Prize in Physics for the third time ever.]