Johann Deisenhofer is a biochemist and biophysicist whose career has been devoted to analyzing the composition of molecular structures. An expert in the use of X-ray technology to analyze the structure of crystals, he became part of a team of scientists in the 1980s who were studying photosynthesis--the process by which plants convert sunlight into chemical energy. In 1988, he shared the Nobel Prize for Chemistry with Robert Huber and Hartmut Michel, awarded for their work in mapping the chemical reaction at the center of photosynthesis.
Deisenhofer was born September 30, 1943, in Zusamaltheim, Bavaria, approximately fifty miles from Munich, Germany. He was the only son of Johann and Thekla Magg Deisenhofer; his parents were both farmers and they expected him to take over the family farm, as was the tradition. It was clear from an early age, however, that Deisenhofer was not interested in agriculture, and his parents sent him away to school in 1956. Over the next seven years, Deisenhofer attended three different schools, graduating from the Holbein Gymnasium in 1963. He then took the Abitur, an examination German students must take in order to qualify for university. He passed the exam and was awarded a scholarship. He then spent eighteen months in the military, as was required for young German men, before enrolling at the Technical University of Munich to study physics. His interest in physics had been developed through reading popular works on the subject, and he had an early passion for astronomy. Deisenhofer soon found himself doing an increasing amount of work in solid-state physics, which concerns the structures of condensed matter or solids. He secured a position in the laboratory of Klaus Dransfeld, and there he narrowed his interests further to biophysics, the application of the principles of the physical sciences to the study of biological occurrences. In 1971, Deisenhofer published his first scientific paper and received his diploma, roughly equal to a master's degree. He then began work on his Ph.D. in biochemistry at the Max Planck Institute in Munich under the direction of Robert Huber. Here, Deisenhofer began using a technique known as X-ray crystallography, which had first been demonstrated by Max Laue in 1912.
A crystal is a solid characterized by a very ordered internal atomic structure. The structural base of any crystal is called a lattice, which is defined by M.F.C. Ladd and R.A. Palmer in Structure Determination by X-ray Crystallography as "a regular, infinite arrangement of points in which every point has the same environment as any other point." Crystallography, the study of crystals, is considered a field of the physical sciences, and X-ray crystallography is the study of crystals using radiation of known length. When X rays hit crystals, they are scattered by electrons. Knowing the wavelength of the X rays used, and measuring the intensities of the scattered X rays, the crystallographer is able to determine first the specific electron structure of the crystal and then its atomic structure.
Deisenhofer finished work for his Ph.D. in 1974. He chose to remain in Huber's laboratory and continue his work with X-ray crystallography, first on a postdoctoral basis, and later as a staff scientist. At the same time, he was developing computer software to be used in the mapping of crystals. While working on his doctorate, Deisenhofer had embarked on a collaborative effort with Wolfgang Steigemann; they studied crystallographic refinement of the structure of Bovine Pancreatic Trypsin Inhibitor, and their findings were published in Acta Crystallographica in 1975.
Collaboration Leads to Nobel
In 1979, Hartmut Michel joined Huber's laboratory. He had been studying photosynthesis for several years and was trying to develop a method for a detailed analysis of the molecules essential to this reaction. Photosynthesis is a very complicated process, about which much is still not known. The photosynthetic reaction center, which is a membrane protein, is considered a key to understanding the process, since it is here the electron receives the energy which drives the reaction. In 1981, Michel discovered a way to crystallize the photosynthetic reaction center from the purple bacterium Rhodopseudomonas viridis. Once Michel had developed this technique, he turned to Huber for help in analyzing it. Huber directed Michel to Deisenhofer, and a four-year collaboration began.
Deisenhofer, with Kunio Miki and Otto Epp, used his X-ray crystallography techniques to determine the position of over 10,000 atoms in the molecule. They produced the first three-dimensional analysis of a membrane protein. New Scientist magazine, as quoted in Nobel Prize Winners Supplement 1987-1991, called the combined efforts "the most important advance in the understanding of photosynthesis for twenty years." The Royal Swedish Academy of Sciences awarded the 1988 Nobel Prize for Chemistry jointly to Huber, Michel, and Deisenhofer for this work. Their findings opened the possibility of creating artificial reaction centers, but the scientists were credited with more than an increase in knowledge of photosynthesis. Their findings will aid efforts to increase the scientific understanding of other functions, such as respiration, nerve impulses, hormone action, and the introduction of nutrients to cells. Deisenhofer and Michel were also recipients of the 1986 Biological Physics Prize of the American Physical Society and the 1988 Otto-Bayer Prize.
In 1987, Deisenhofer accepted the Virginia and Edward Linthicum Distinguished Chair in Biomolecular Science at the University of Texas Southwestern Medical Center at Dallas; his goal there is to establish a major center for X-ray crystallography. He has continued his research interests in the areas of protein crystallography, macromolecules, and crystallographic software. Deisenhofer has been awarded the Knight Commander's Cross of the Order of Merit of the Federal Republic of Germany, as well as the Bavarian Order of Merit. He is a fellow of the American Association for the Advancement of Science and a member of the American Crystallographic Association, the German Biophysical Society, and Academia Europa. In 1993, Deisenhofer, with James R. Norris of the Argonne National Laboratory, published a two-volume book called The Photosynthetic Reaction Center, based on work that grew out of Diesenhofer's collaboration with Michel.
Deisenhofer was married in 1989 to a fellow scientist, Kirsten Fischer Lindahl. He enjoys music, history, skiing, swimming, and chess in his free time. After Diesenhofer won the Nobel Prize, Dr. Kern Wildenthal, president of the Southwestern Medical School, described him to the New York Times as "very shy" and a man whose "life was his work." Wildenthal further observed that the scientist is "quiet, peaceful and calm. But beneath that exterior, he is scientifically fearless."
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