Frances Arnold

Pioneer of directed evolution awarded the Nobel Prize in Chemistry for enzyme engineering

Frances Arnold, an American chemical engineer, revolutionized biotechnology by developing directed evolution, a method to engineer enzymes for sustainable chemistry. Awarded the 2018 Nobel Prize in Chemistry, her work enables the creation of biofuels, pharmaceuticals, and environmentally friendly industrial processes.

Arnold began her career at Princeton University, where she studied mechanical and aerospace engineering. A growing interest in renewable energy led her to UC Berkeley for graduate studies in chemical engineering. In the 1990s, she pioneered directed evolution at Caltech, mimicking natural selection to optimize enzymes. By introducing random mutations and selecting proteins with desired traits, she created enzymes that perform reactions not found in nature.

One landmark achievement was engineering a cytochrome P450 enzyme to catalyze carbon-silicon bonds—a reaction absent in biological systems. This breakthrough, published in Science, demonstrated the vast potential of bioengineered catalysts. Arnold's methods are now industry standards, used to produce drugs like Januvia (for diabetes) and sustainable alternatives to petroleum-based chemicals.

An advocate for green chemistry, Arnold co-founded Gevo, a company developing bio-based fuels. She also serves on the President’s Council of Advisors on Science and Technology. Despite facing gender barriers in engineering, she remains a role model, emphasizing perseverance and intellectual risk-taking.