Three investigators with university appointments in the United States and France were named co-winners of the 2013 Nobel Prize in Chemistry this morning for laying the groundwork behind today’s computer models for understanding and predicting chemical processes—models whose applications include drug discovery.
Martin Karplus, Ph.D., of Harvard University and France’s University of Strasbourg, Michael Levitt, Ph.D., of Stanford University School of Medicine, and Arieh Warshel, Ph.D., of the University of Southern California were cited “for the development of multiscale models for complex chemical systems,” namely, models that marry the classical physics of Isaac Newton with quantum physics in modeling processes that involve chemical reaction.
Previously, chemists had to choose to use either classical or quantum physics, the Royal Swedish Academy of Sciences noted in announcing today’s prize, which includes 8 million Swedish kronor (about $1.2 million) to be shared by the three laureates.
“We were always sure the theoreticians were wrong again” any time experimentation didn’t match theoretical results based on simpler past computer simulations, Sven Lidin, chairman of the selection committee, stated in an interview webcast on the Nobel Prize website.
In drug discovery, the academy noted, marrying classical and quantum physics has entailed simulations of how a drug binds with its target protein in the body—combining computer-generated quantum theoretical calculations on atoms in the target protein interacting with the drug, while simulating the rest of the large protein using classical physics.
“In short, what we developed is a way which requires computers to look, to take the structure of a protein, and then to eventually understand how exactly it does what it does,” Dr. Warshel said at a press conference following the announcement of the prize winners.
“If you have an enzyme that digests food, and the structure exists, you want to understand exactly how it’s happening. And then, you could use it to design drugs, or in my case, to satisfy your curiosity,” added Dr. Warshel, distinguished professor in chemistry at USC.
At present, he said, he continues to apply the combination of quantum and traditional molecular mechanics to understand how increasingly complex molecules such as proteins transfer signals within cells. “Our current studies continue in pursuing the frontiers of the field focusing on developing rigorous yet effective ways for evaluation of activation free energies of enzymatic reactions,” according to the home page of Dr. Warshel’s lab.
Asked how he felt upon winning, Dr. Warshel said on the webcast he felt “extremely, extremely well.”
The work being honored began in the early 1970s when, from his Harvard lab, Dr. Karplus developed programs capable of simulating chemical processes by applying quantum physics.
Dr. Warshel met Dr. Levitt, now the Robert W. and Vivian K. Cahill Professor in Cancer Research at Stanford Medicine, while both were in the laboratory of Shneior Lifson at Israel’s Weizmann Institute of Science. Dr. Warshel later worked in the lab of Dr. Karplus, now the Theodore William Richards Professor of Chemistry, Emeritus at Harvard’s department of chemistry and chemical biology.
Drs. Warshel and Levitt published a landmark paper in 1976 in the Journal of Molecular Biology that introduced the hybrid quantum mechanical/molecular mechanics method and a microscopic dielectric model that represented an entire enzyme-substrate complex in solution. This facilitated the first consistent modeling of the catalytic effect of an enzyme.
“We had the idea about doing computer calculations on the large molecules that make life possible,” Dr. Levitt recalled in remarks published this morning on Stanford Medicine’s Scope blog.
“Like everyone else, one is surprised,” he said of the early morning call informing him that he had won the Nobel prize. The first person he contacted to share the news was his 98-year-old mother in London, whom he reached by telephone.
“Now I just hope to get through the day and make sure that, in the end, my life doesn’t change very much. Because I really have a wonderful life,” Dr. Levitt added.