Peter A. Kollman (1944–2001)

Abstract

Peter A. Kollman (Figure 1)(Figure 1) died earlier this year after a brief but inspirational struggle with cancer at the age of 56. Although his career was foreshortened, his contributions to the application of quantum and molecular mechanics calculations to address important chemical and biological problems will live on in the students he trained and the AMBER suite of programs that he produced. His booming voice, unbridled enthusiasm for science, generosity of spirit, and friendship will all be missed.Figure 1Peter KollmanView Large Image | View Hi-Res Image | Download PowerPoint SlideI came to know Peter Kollman during his first sabbatical. I had moved to Oxford for graduate school and Peter had come to immerse himself in structural biology. His interests were drawn to extending detailed computational chemistry tools to study biological macromolecules. This was 1978, and the era of distributed computing had not yet arrived. Instead, the computer that we used was centralized and filled a very large room. The staff could be watched mounting magnetic tapes on large drives. Even in Oxford, air-conditioning was required. Punch cards were the norm, although the first terminals were becoming more common. Peter dashed off an early version of what would ultimately become AMBER, and I set out to calculate the energy landscape of an interacting pair of helices in vacuo. We learned several things: the computers were not fast enough, there were too many variables to manage, and a CalComp plotter drawing stereo images was a tough way to analyze the results. To his credit, Peter was not deterred. I sought out simpler problems that might lead to completion of my degree.Peter went on to build an incredibly productive research and training program. Through over 400 publications, Peter and his students and collaborators helped us to understand the behavior of water, alkanes, peptides, nucleic acids, proteins, and pharmaceuticals. Perhaps he is best known for his scholarly contributions to the field of Free Energy Perturbation calculations. While several scientists understood that it would be easier to simulate the alchemical transformation of a hydrogen atom to a methyl group attached to a complex macromolecular system in two or more distinct conformations, Peter foresaw the power of this method to address important medicinal and biochemical problems. To paraphrase one of his colleagues, I knew that Free Energy Perturbation calculations were important and wrote two papers on this subject; Peter wrote fifty. Encapsulated within this observation is Peter's enthusiasm for his work. This enthusiasm was effectively transmitted to his students who now hold important academic and industrial positions. Peter's enthusiasm was evident in all aspects of his life. He was a devoted husband and father to his children and step-children. Whether it was basketball, tennis, or ping pong, he loved to compete and he always wanted to play. I had the pleasure of playing with Peter. There was always a kind word for a good shot and enthusiastic support delivered with a booming baritone.Peter developed weight loss earlier this year that he attributed to an overzealous exercise program. A visit to his doctor and follow up tests led to a more insidious conclusion, a cancer of uncertain origin that had spread to his liver and bones. For all of Peter's work on the mechanism of action of DNA intercalaters, his disease had progressed too far to benefit from chemotherapy. We discussed the medical options. Peter reached the brave conclusion that the rigors of aggressive chemotherapy would not enhance the quality of his life. Instead, he decided to spend what time he had left with his family and friends. Peter told me more than once that he had no regrets. He had the good fortune to work on problems he loved with colleagues that he enjoyed. At a time when many of us would focus on all that we had not made time for, Peter displayed a rare sense of contentment as he listened to the music he loved and sent out a few extra e-mail messages. In the last few weeks of his life, the bone pain from his tumor required morphine. When discussing mundane subjects, he had a difficult time staying focused. But, when his thoughts turned to science, he was as lucid as ever. Science clearly held a privileged spot in Peter's mind, a spot that was not subject to ephemeral or biochemical distraction.I will miss him greatly.[One of Dr. Kollman's last papers appears on pp. 905–916 of this issue.]