Nobel winners in chemistry pushed evolutionary biology

Three scientists shared this year’s Nobel Prize in chemistry for tapping the power of evolutionary biology to design molecules with a range of practical uses. Those include new drugs, more-efficient and less-toxic reactions in the manufacture of chemicals and plant-derived fuels to replace oil, gas and coal.

Half of the prize and the accompanying $1 million went to Frances Arnold, a professor of chemical engineering at the California Institute of Technology. She is only the fifth woman to win a chemistry Nobel and the first since 2009.

The other half of the prize is shared by George Smith, an emeritus professor of biological sciences at the University of Missouri, and Gregory Winter, a biochemist at the MRC Laboratory of Molecular Biology in England.

“I always wanted to be a protein engineer,” Arnold said. “I wanted to be an engineer of the biological world. … I copied nature’s inventions, this wonderful process of evolution, to breed molecules like you breed cats and dogs.”

For this “directed evolution” research, Arnold inserted the gene that produced the enzyme she wanted to study into fast-reproducing bacteria. With mutations of the gene, she could then examine how well variations of the enzyme worked. She chose the one that worked best and repeated the process — just like evolution chooses the survival of the fittest over succeeding generations.

In her initial experiments in the 1990s, she was able to find an enzyme more than 200 times as effective as the one she started with by the third generation.

Smith and Winter harnessed the power of bacteriophages — viruses that infect bacteria — for applications that eventually contributed to novel drugs that treat a range of diseases.

The first antibody drug developed this way, adalimumab, which is sold under the brand name Humira, was approved in 2002 to treat rheumatoid arthritis, psoriasis and inflammatory bowel diseases.

Other antibodies are used to kill cancer cells, neutralize anthrax and slow the progress of lupus, an autoimmune disease. Additional antibodies are in testing to treat diseases like Alzheimer’s.