Frances Arnold

Frances Arnold is an American scientist and engineer renowned for pioneering the directed evolution of enzymes, a revolutionary method for protein engineering. Her work, which harnesses the principles of natural selection to create novel biological catalysts, has had profound impacts across pharmaceuticals, renewable energy, and industrial chemistry. A professor at the California Institute of Technology, she was awarded the Nobel Prize in Chemistry in 2018, becoming the fifth woman to receive that honor. Her research continues to drive innovations in sustainable technology and green chemistry.

Early life and education

Born in Pittsburgh, she developed an independent spirit early on, moving out at a young age and working various jobs including as a taxi driver and cocktail waitress. She pursued undergraduate studies in mechanical and aerospace engineering at Princeton University, earning her Bachelor of Science degree in 1979. Following a stint working on solar energy projects in Chile and at the Solar Energy Research Institute in Colorado, she shifted her academic focus. She then completed her doctorate in chemical engineering at the University of California, Berkeley in 1985, conducting postdoctoral research at UC Berkeley and the California Institute of Technology before joining the Caltech faculty.

Scientific career and research

After joining the faculty at the California Institute of Technology, she established a research program focused on protein engineering and biocatalysis. Her early work sought to understand and improve the stability and function of enzymes in non-natural environments, such as industrial solvents. This quest led her to challenge the prevailing rational design approaches of the 1980s and early 1990s, which relied on detailed structural knowledge from techniques like X-ray crystallography. Instead, she proposed mimicking Darwinian evolution in the laboratory, a conceptual leap that would define her career. Her laboratory's breakthroughs have been applied by numerous companies in sectors ranging from agriculture to medicine, and she co-founded several biotechnology firms, including Gevo and Provivi.

Directed evolution of enzymes

The method of directed evolution developed involves introducing random mutagenesis into the gene encoding a target enzyme, creating a vast library of variants. These variants are then expressed and subjected to a selective pressure for a desired function, such as catalyzing a new chemical reaction or operating in high temperatures. The best-performing variants are identified, and the process of mutation and selection is repeated over multiple generations, mimicking natural selection. This technique has successfully created enzymes for manufacturing pharmaceuticals like sitagliptin, for producing renewable fuels, and for synthesizing novel materials. It represents a fundamental advance in biotechnology, providing a powerful tool for the green chemistry movement by enabling more efficient and less toxic industrial processes.

Awards and honors

Her contributions have been recognized with numerous prestigious awards. She was elected to all three major United States National Academies: the National Academy of Sciences, the National Academy of Engineering, and the National Academy of Medicine. She received the National Medal of Technology and Innovation from President Barack Obama in 2011 and was inducted into the National Inventors Hall of Fame in 2014. The apex of her recognition came in 2018 when she was awarded the Nobel Prize in Chemistry, which she shared with George Smith and Sir Gregory Winter. Other notable honors include the Millennium Technology Prize (2016) and the Charles Stark Draper Prize (2019).

Personal life and advocacy

She is a vocal advocate for science policy and diversity in STEM fields, often speaking about her own experiences. She has served on various high-level advisory councils, including the President's Council of Advisors on Science and Technology under the Obama administration. In her personal life, she is a mother of three sons and has been open about her battles with breast cancer. An accomplished pilot, she has also flown solo across the Atlantic Ocean. She actively promotes the global adoption of sustainable chemistry practices and continues to mentor the next generation of scientists at Caltech and through her public engagements.