Nobel Prize in Chemistry Awarded to Frances H. Arnold

Dr. Arnold, a 62-year-old professor of chemical engineering, bioengineering and biochemistry at the California Institute of Technology in Pasadena, received the award for his work on enzyme evolution. In the 1980s, Dr. Arnold attempted to rebuild enzymes, but struggled to reprogram their genes to acquire new properties because they are highly complex molecules made of different amino acids that could be combined in unlimited ways. Previously, he attempted to modify an enzyme called subtilisin. He wanted it to accelerate change in an organic solvent, so he created random mutations in the enzyme's genetic code and introduced the mutated genes into bacteria that subsequently produced different subtilisin variants. Dr. Arnold selected the subtilisin variant that performed best. Once he found the best subtilisin variant, he continued his work by modifying it repeatedly until he obtained the optimal version. Through this directed evolution, rather than relying on human logic and understanding how genes and enzymes should work, he was able to demonstrate the power behind allowing chance and directed selection. This was the first step toward revolution in enzyme mutation. Speaking at a press conference at Caltech on Wednesday, Dr. Arnold predicted a "steady stream" of future Nobel Prizes in Chemistry going to women. Arnold stated: "This is simply a rich resource. As long as we encourage everyone—color, gender does not matter; anyone who wants to do science, we encourage them to do it—we will see Nobel Prizes coming from all these different groups. Women will be very successful."