Johann Deisenhofer

DEISENHOFER, JOHANN (1943-). Awarded the Nobel prize for chemistry in 1988. along with Robert Huber and Hanmut Michel, for work that revealed the three-dimensional structure of closely linked proteins that are essential to photosynthesis. Doctorate awarded in 1974 by Max Planck Institute of Biochemistry. Germany. 

The structure of the UQ-cyt c reductase, also known as the cytochrome bc complex, has been determined by Johann Deisenhofer and his colleagues. (Deisenhofer was a co-recipient of the Nobel Prize in Chemistry for his work on the structure of a photosynthetic reaction center [see Chapter 22]). The complex is a dimer, with each monomer consisting of 11 protein subunits and 2165 amino acid residues (monomer mass, 248 kD). The dimeric structure is pear-shaped and consists of a large domain that extends 75 A into the mito-... 

What molecular architecture couples the absorption of light energy to rapid electron-transfer events, in turn coupling these e transfers to proton translocations so that ATP synthesis is possible Part of the answer to this question lies in the membrane-associated nature of the photosystems. Membrane proteins have been difficult to study due to their insolubility in the usual aqueous solvents employed in protein biochemistry. A major breakthrough occurred in 1984 when Johann Deisenhofer, Hartmut Michel, and Robert Huber reported the first X-ray crystallographic analysis of a membrane protein. To the great benefit of photosynthesis research, this protein was the reaction center from the photosynthetic purple bacterium Rhodopseudomonas viridis. This research earned these three scientists the 1984 Nobel Prize in chemistry. 

Johann Deisenhofer Germany and United States, b. Germany photosynthesis... 

For many years, die nature and location of the complex of proteins (sometimes referred to as the engine of photosynthesis) were poorly understood. During the 1980s, much more was learned as the result of research carried out by Johann Deisenhofer (Howard Hughes Medical Institute), Robert Huber, and Harmut Michel (Max Planck Institute), and for this work the investigators were awarded the 1988 Nobel Prize for chemistry. The protein complex, called the membrane-bound proteins, are difficult to define structurally because they do not crystallize readily and thus could not be subjected to x-ray crystallography. However, over a period of three years, the researchers were able to create crystals and thus were able to determine precisely the position of some 10,000 atoms in the protein complex. 

Johann Deisenhofer, Howard Hughes Medical Institute, The University of Texas, Dallas,... 

The crystal structure of reaction centers from R. viridis was determined by Hartmut Michel, Johann Deisenhofer, Robert Huber, and their colleagues in 1984. This was the first high-resolution crystal structure to be obtained for an integral membrane protein. Reaction centers from another species, Rhodobacter sphaeroides, subsequently proved to have a similar structure. In both species, the bacteriochlorophyll and bacteriopheophytin, the iron atom and the quinones are all on two of the polypeptides, which are folded into a series of a helices that pass back and forth across the cell membrane (fig. 15.1 la). The third polypeptide resides largely on the cytoplasmic side of the membrane, but it also has one transmembrane a helix. The cytochrome subunit of the reaction center in R. viridis sits on the external (periplasmic) surface of the membrane. 

Figure 3-6. (a) Molecules illustrating C symmetries (b) The structure of the photosynthetic reaction center with approximate C2 symmetry (courtesy of Johann Deisenhofer, Dallas, Texas) [15],... 

Tou had been appointed to a directorship before the Nobel Prize whereas Johann Deisenhofer had difficulties in securing a similar position in Germany. What was the difference ... 

Johann Deisenhofer and Hartmut Michel at the reception of the Nobel Foundation during the centennial Nobel celebrations in Stockholm, December 2001 (photograph by I. Hargittai). 

Johann Deisenhofer received his Diploma in Physics from the Technical University of Munich in 1971 and his Dr. rer. nat. degree in 1974 from the Technical University of Munich for research done at the Max-Planck-Institute for Biochemistry in Martinsried under Robert Huber. His thesis work was the structure refinement of the basic pancreatic trypsin inhibitor at 1.5 angstrom resolution. He worked as a Research Associate and then as Staff Scientist at the Max Planck Institute between 1974 and 1988. He habilitated at the Technical University Munich in 1987. He has been at the University of Texas Southwestern Medical Center at Dallas since 1988. 

Overall view of the reaction center structure and view along the approximate symmetry axis. Protein chains are represented as curved lines (courtesy of Johann Deisenhofer). 

Hartmut Michel was Dieter Oesterhelfs associate and Johann Deisenhofer was yours. Oesterhelt was also a director at the Max Planck Institute so you were of equal ranking. Then came the Nobel Prize, which included Deisenhofer, Huber, and Michel. Oesterhelt was not a co-author of the papers reportin 0 the structure determination of the photosynthetic reaction center, and more than three persons could not have shared the Nobel Prize in the first place. My question is, how much change did the Nobel Prize introduce into your careers Was there a watershed effect ... 

Johann Deisenhofer, Robert Huber, Hartmut Michel... 

Color Plate 1. Side view of Rp. viridls reaction-center model. See book cover for the broad view of the same model. Both figures are kindly provided by Dr. Johann Deisenhofer. (See Chapter 2, Fig. 7.)... 

Johann Deisenhofer (1943- ), Federal Republic of Germany, Robert Huber (1937- ), Federal Republic of Germany, and Hartmut Michel (1948- ), Federal Republic of Germany. For the determination of the three-dimensional structure of a photosynthetic reaction center. ... 

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