Sometimes it’s amazing living and working in the Silicon Valley. Glew Engineering Consulting’s office is located in the thick of it all – Mountain View – home to Google, next door to Palo Alto’s HP and Facebook, the heart of the Silicon Valley. Palo Alto is also home to Stanford University. Several consultants from Glew’s team are Stanford graduates, so it’s easy to stay connected with academia and technology. Reading a Stanford news bulletin lately was indeed a thrill – a Stanford professor was awarded the Nobel Prize in Chemistry this past October!
Dr. Michael Levitt, Stanford University School of Medicine, Dr. Martin Karplus, Université de Strasbourg, France and Harvard University, and Dr. Arieh Warshel, University of Southern California, Los Angeles all share the 2013 Nobel Prize in Chemistry. Below is their story of how they created a computer model that maps chemical reactions.
Chemical reactions occur so fast, in a fraction of a millisecond. Classical chemistry can hardly keep pace, making it almost impossible to experimentally map every step in a chemical process. In the past, if scientists wanted to simulate molecules on the computer they had to choose between software that was based upon either classical Newtonian physical theories or quantum physics. Classical physics programs had it strengths with simple calculations that could be used to model and process large molecules. The molecules could only be displayed in a state of rest however, but allowed scientists a basic understanding of how the atoms were positioned in the molecules. If you wanted to stimulate a reaction, where the molecules are filled with energy, classical physics programs were not an option, as classical physics has no understanding of such states. To stimulate reactions, scientists had to turn to quantum physics, which supports a theory that electrons can be both particles and waves simultaneously. Quantum physic calculations require enormous computing power however, as the computer had to process every electron and every atomic nucleus in the molecule. 1970s computers could only perform calculations on small molecules and had to ignore interactions with the surrounding environment.
The 2013 Nobel Laureates in Chemistry opened the doors that allowed for collaboration between Newton’s classical physics and quantum physics. In the early 1970s Dr. Karplus was working at Harvard University to develop computer programs that could simulate chemical reactions with the help of quantum physics. Also in early 1970, Dr. Warshel and Dr. Levitt developed a revolutionary computer program that utilized classical theories. Their program allowed for modeling of all sorts of molecules, even large biological molecules. Dr. Washel joined Dr. Karplus at Harvard and together began developing a program that could perform different kinds of calculations on different electrons. In 1972 they published their results: the first chemically relevant collaboration between classical and quantum physics. While ground-breaking their program could only handle molecules with mirror symmetry.
After working at Harvard for two years, Dr. Warshel joined Dr. Levitt with a goal of developing a program that could be used to study enzymes. In order to do this, Dr. Warshel and Dr. Levitt had to make classical and quantum physics collaborate smoothly. In 1976 they finally reached their goal and published the first computerized model of an enzymatic reaction. This model was revolutionary because it could be used for any type of molecule.
Dr. Levitt and Dr. Warshel have worked to streamline their model. The computer does not always have to account for every atom in some parts of the molecule. During their work to improve the model, they demonstrated that it is possible to merge several atoms during the calculations. Dr. Karplus, Dr. Levitt, and Dr. Warshel’s method is very powerful because it is universal. It can be utilized when studying all branches of chemistry. Their methods have led to improvements in solar panel technologies, motor vehicle reactions, and even drug reactions. Now more then ever the computer is as common of a tool to a chemist as the test tube.