"Directed evolution" scientists awarded 2018 Nobel Prize for Chemistry
The 2018 Nobel Prize in Chemistry has been awarded to three scientists who tapped into evolution to produce vital chemicals for medicine and industry. Half of the prize was awarded to Frances H. Arnold, for developing a method of directing the evolution of enzymes, and the other half is shared by George P. Smith and Sir Gregory P. Winter, who manipulated phages to create new antibodies.
Evolution is one of nature's most powerful forces – random genetic mutations may help a particular organism survive, meaning those traits are more likely to be passed down to its offspring. Over time, that of course leads to diverse species that are particularly well-suited to certain biological tasks.
That same technique can be recreated in the lab. Scientists can introduce mutations into the genes of bacteria and other microorganisms, and by selecting those with the desired results and running the tests again, they can end up with microbes that get better and better at a particular job.
Frances Arnold was the first to use directed evolution to produce new, more active enzymes, in research published in 1993. She started by editing the genes in the bacteria that expressed an enzyme, then grew the bugs on plates full of casein and an organic solvent. If the enzyme worked, it would "eat" the casein and leave a clear ring around the bacteria colony. Arnold then selected the bacteria with the biggest rings around them, and repeated the process four times. The end result was an enzyme that was 256 times more active than normal.
Since then, Arnold has continued to refine the process, which nowadays is used to engineer new enzymes and chemicals for pharmaceuticals and renewable fuels.
Smith and Winter developed a similar process in 1985, manipulating bacteriophages to grow new proteins. The technique, known as phage display, involves editing the genes of phages so that they in turn manipulate the bacteria they infect in specific ways. Like Arnold's enzymes, this process can result in antibodies that are more effective against certain ailments. Since then, scientists have used phage display to create antibodies directed at autoimmune diseases and even metastatic cancer.
The Chemistry Prize is the third Nobel Prize to have been awarded this week. The Medicine Prize was awarded to James Allison and Tasuku Honjo for their pioneering work in cancer immunotherapy, while the Physics Prize went to Arthur Ashkin, Gérard Mourou and Donna Strickland for their involvement in advancing laser physics.
Sara Snogerup Linse, member of the Nobel Committee for Physics, discusses the Laureates in the video below.
Source: Nobel Prize organization