Deisenhofer, Johann (1943-…), a German biophysicist, with his colleagues Robert Huber and Hartmut Michel, painstakingly worked out the positions of over 10,000 atoms making up a complex molecule. The molecule plays a key role in photosynthesis, a process in which complex materials of life are built up using the energy of sunlight. The work of Deisenhofer and his colleagues revealed much information about photosynthesis in general. The three scientists won the 1988 Nobel Prize for chemistry for this work.
Deisenhofer’s work involved X-ray crystallography (analysis of crystal structure using X rays) of large biological molecules. By analyzing experimental data, Deisenhofer established the structures of a succession of important biological molecules. He developed computer software to aid in the analysis.
In 1982, Deisenhofer began the work for which he was awarded the Nobel Prize. At that time he was working at the Max Planck Institute for Biochemistry at Martinsried, near Munich, Germany. Hartmut Michel, a colleague at the institute, had succeeded in crystallizing an important molecule found in a certain bacterium. This molecule, called the bacterium’s photosynthetic reaction center, forms part of the bacterium’s cell wall. The reaction center molecule did not combine with water, and no one had succeeded in crystallizing it. Michel achieved this feat in 1981, using a substitute for water. This meant that it could now be studied by X-ray crystallography, and in 1982 Deisenhofer began to work with Michel and others to analyze the structure. It took until 1985 to establish the rough structure of the molecule and another two years to clarify the fine structure, with a level of detail approximately equal to an atom’s diameter.
Deisenhofer was born in Zusamaltheim, a village in Bavaria. After military service, he began to study physics at the Munich Technical University in 1965. He became interested in solid-state physics and then in biophysics, the physics of life processes. By 1974, he had gained a Ph.D. at the Max Planck Institute for Biochemistry headed by Robert Huber, and stayed to continue his research. In 1988, Deisenhofer became professor of biochemistry at the University of Texas Southwestern Medical Center at Dallas, continuing his research on the structure of giant molecules.
