Martin Karplus is one of three winners of the 2013 Nobel Prize in Chemistry. This year’s laureates have opened a door between the worlds of classical and quantum physics. The first step toward this collaboration was taken in Karplus’ laboratory at Harvard University at the beginning of the 1970s. His research group developed computer programs that could simulate chemical reactions with the help of quantum physics. Arieh Warshel came to visit Karplus at Harvard.

The goal was to study molecules similar to retinal, a cromophore responsible for animal vision that had attracted the attention of Karplus. They started out with similar molecules of a more simple structure and constructed a computer program that drew on quantum physics when it performed calculations on free electrons. In addition the program also applied more simple classical theories for all other electrons and all atomic nuclei. Karplus and Warshel published their results in 1972. That was the first work to show that it’s possible to construct hybrid methods combining the advantages of classical and quantum methods to describe complex chemical systems. 

A pioneer

Martin Karplus is also well-known as a pioneer in the application of nuclear magnetic resonance in chemistry. During his years as a postdoctoral fellow at Oxford, Martin Karplus became interested in finding areas where theory could make a contribution of general utility in chemistry. He entered into the field of magnetic resonance, which was a vital new area at the time. Karplus returned to the states, started at the University of Illinois and devoted a major part of his research on theoretical methods for relating nuclear and electron spin magnetic resonance parameters to the electronic structures of molecules. He later developed what is known as the  Karplus equation, a well-known method among chemists that is based on the quantum chemical properties of molecules  and is used within nuclear magnetic resonance (NMR).  

The computational methods the three Nobel laureates pioneered in the 1970s are now routinely used by chemists to understand how molecules will interact, including understanding how drugs interact with proteins in the body. The approach has been used to understand how to inhibit an enzyme in HIV, for example, and to understand the formation of amyloid fragments in the brains of people with Alzheimer’s disease. 

I always said that the dream for these methods is that they become another tool that experimentalists use to help them understand what their experiments mean.

“I think the most important thing is to understand the living world much better than we did before and talk about all the drugs that more and more are being based on computational methods. Today there are some unbelievable applications, to which we contributed by making the understanding available. That was not really the original objective. We just wanted to understand things. I always said that the dream for these methods is that they become another tool that experimentalists use to help them understand what their experiments mean,” says Martin Karplus.

Even though the prize is awarded in chemistry, it was actually biology that drew his attention from the beginning. “I’ve always liked to understand things,” he says. His older brother Bob was given a chemistry set and started doing experiments. Inspired by his brother Martin Karplus pleaded for a chemistry set of his own. But his parents were worried what the results would be if two teenage boys had two chemistry sets and instead gave the younger brother a microscope.

At first he wasn’t overjoyed about receiving the microscope, seeing this more as a second prize relative to the chemistry set. But then he started using it, looking at things swimming around, particularly the rotifers which he found to be amazing little creatures turning and swimming in any direction.

“I wanted to understand how this could work. I started observing nature, similar to my father. He liked to go fishing as an excuse to observe the fishes and their behavior. I think that also helped to excite my interest,” Martin Karplus explains.

Eventually this led him to grow a deeper love for nature and birds, and he decided that he really wanted to understand biology. “I started out learning chemistry and physics, because that’s the way to understand biology at a fundamental level,” Martin Karplus states. 

Martin Karplus was born in Vienna in 1930. The family managed to escape the Nazi takeover of Austria in 1938 by slipping out of the country to Switzerland and then some months later the family started a new life in the United States. Growing up in another country gave him a push and a desire to succeed. Also, his father’s optimistic mindset had an influence on him and his view on life and science, he says.

You have to have faith somehow that if you work at it, if you look at it in different ways, you will be able to solve the problems that first maybe were very difficult to solve.

“I think that had a great effect on me. I’m very optimistic about things and I sort of forget the past when things didn’t work out and remember the positive parts. I think that has been very important in my life, as when you’re doing research you don’t always succeed. You have to have faith somehow that if you work at it, if you look at it in different ways, you will be able to solve the problems that first maybe were very difficult to solve,” Martin Karplus advises.

The desire to comprehend the world around him, combined with an attraction toward unexplored areas, is the driving force in Martin Karplus’ scientific work. “I want to understand things that nobody else has understood before. Each time I had understood a certain area I then got somewhat bored with it and I tried to find something new,” He says. His characteristic fascination and curiosity is reflected in his two other big passions in life: food (he’s an amateur chef who for years during vacations volunteered to work in the kitchens of three-star restaurants in France and Spain) and photography.

I have a way of seeing very quickly a scene and sort of just composing it.

The 83-year-old Nobel laureate, contemplative, slightly modest, gets the same intensive glow in his eyes when describing his love for science as when he talks about photography.

“I have a way of seeing very quickly a scene and sort of just composing it. My ability to focus very quickly and see a scene comes partly from when I was bird watching. When you see some little thing somewhere out there you have to be able to take your binoculars and focus on that thing. It’s this instant moment when I see something and just do it,” Martin Karplus states.

Martin Karplus
  • Family: Wife and three children.
  • Position: Theodore William Richards Professor of Chemistry, Emeritus, at Harvard University and Director of the Biophysical Chemistry Laboratory, a joint laboratory of the French National Center for Scientific Research and the University of Strasbourg, France.
  • Career: PhD in Chemistry, California Institute of Technology (1953), postdoctoral fellow in Oxford, England, Professor of Chemistry at Harvard University (1966), Profeseur Conventionné at the Université Louis Pasteur (1996).